,, 张吉旺, 赵斌, 任佰朝山东农业大学农学院/作物生物学国家重点实验室,山东泰安 271018Effects of Different Cultivation Modes on Canopy Structure and Photosynthetic Performance of Summer Maize
LI Jing, WANG HongZhang, XU JiaYi, LIU Peng,, ZHANG JiWang, ZHAO Bin, REN BaiZhaoCollege of Agriculture, Shandong Agricultural University/State Key Laboratory of Crop Biology, Taian 271018, Shandong通讯作者:
责任编辑: 杨鑫浩
收稿日期:2020-01-19接受日期:2020-06-30网络出版日期:2020-11-16
| 基金资助: |
Received:2020-01-19Accepted:2020-06-30Online:2020-11-16
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李静, 王洪章, 许佳诣, 刘鹏, 张吉旺, 赵斌, 任佰朝. 不同栽培模式对夏玉米冠层结构及光合性能的影响[J]. 中国农业科学, 2020, 53(22): 4550-4560 doi:10.3864/j.issn.0578-1752.2020.22.003
LI Jing, WANG HongZhang, XU JiaYi, LIU Peng, ZHANG JiWang, ZHAO Bin, REN BaiZhao.
开放科学（资源服务）标识码（OSID）：
0 引言
【研究意义】玉米作为我国第一大粮食作物,在维护国家粮食安全中发挥重要作用,高产栽培模式探究对进一步提高玉米单产保证增产至关重要[1],合理增大种植密度是玉米高产的有效途径[2]。光照是影响作物生长发育的关键环境因子,它通过影响叶片发育、激活光合作用关键酶、增强生理反应需要的能量供应等过程调节作物光合作用[3]。密植群体易造成叶片间相互遮荫[4],导致群体内光分布不合理,影响叶片结构发育,直接影响叶片光合性能及群体光能利用效率,形成不合理的群体冠层结构[5]。叶绿体是作物进行光合作用的场所,群体内光照条件会对叶绿体结构产生影响,进而影响叶片光合性能[6]、同化物的积累及产量形成[7]。探究不同栽培模式群体内夏玉米冠层结构特性、叶片发育特点与光合性能的差异,阐明不同群体冠层结构对夏玉米叶片超微结构、叶片光合性能的影响,对进一步研发夏玉米高产栽培技术具有重要意义。【前人研究进展】增大种植密度、调整氮肥用量及施肥方式是研究较多的提高产量的栽培措施。单纯增大种植密度,会导致玉米叶片之间相互遮荫,中下部叶片受光不足,加快下部叶片及根系衰老速度[4, 8]。氮肥合理运筹[9]、优化株行距配置[10,11,12]可调节叶片着生状态,构建合理的群体冠层结构,中下部叶片接收更多光能[13],改善群体内光环境。综合密植和优化肥料运筹的栽培措施可提高氮肥利用率[14]和光能生产效率[15]。光照会通过影响叶片发育、调节叶绿体超微结构,进而影响叶片光合作用[16],叶片受光不足时,叶绿体排布变得不规则,结构膨胀、基粒片层排列异常、基粒个数和片层数减少,叶绿体膜开始溶解,导致叶片早衰[17,18],影响其光合作用。【本研究切入点】尽管有较多****对夏玉米群体结构、光合性能进行了研究,但多集中在密度、肥料等单一措施的影响,关于不同栽培措施对夏玉米群体发育及光合性能的综合影响的研究相对较少,难以系统解释夏玉米生长发育及产量形成过程中所受外界因素的综合影响,难以精准确定增产措施。【拟解决的关键问题】本文通过研究夏玉米不同栽培模式的群体冠层特性、叶片发育状况及其光合能力,从所处光环境及叶绿体结构两方面分析不同群体内叶片光合能力及产量差异的原因,为进一步制定可构建高效冠层结构的夏玉米高产栽培模式提供理论依据。1 材料与方法
1.1 试验区概况
本试验于2018—2019年在山东省泰安市岱岳区马庄镇（35°58′41″N,116°58′22″E）进行,播前土壤耕层养分含量为有机质9.22 g·kg-1,碱解氮70.54 mg·kg-1,速效磷35.75 mg·kg-1,速效钾137.57 mg·kg-1。该区域为温带季风性气候,种植制度为一年两熟,夏玉米生育期内（6—10月）日平均气温、日光合有效辐射量、降雨量详见图1。室内试验在山东农业大学作物生物学国家重点实验室进行。图1
新窗口打开|下载原图ZIP|生成PPT图1玉米生育期内试验地的日平均气温、日光合有效辐射、日降雨量
Fig. 1Daily average temperature, effective photosynthetic radiation, and daily rainfall of the test site during the maize growth period
1.2 试验设计
本试验以玉米品种登海605为材料,在同一地块结合种植密度、肥水管理及种植方式设置超高产（SH）、高产高效（HH）、农户习惯（FP）3种栽培模式,各处理的具体种植密度、肥料管理详见表1。试验所用氮肥为包膜缓控尿素（PU,含N 42%）和普通尿素（U,含N 46%）,磷肥为过磷酸钙（含P2O5 12%）,钾肥为硫酸钾（含K2O 51%）,有机肥料为山东友邦肥业科技有限公司生产的商品有机肥（含有机碳（干基）304 g·kg-1、P2O5 31.2 g·kg-1、K2O 30.4 g·kg-1、C/N为11.2）。试验为随机区组设计,各试验小区长18 m、宽12 m,3次重复,各小区之间设立1 m的隔离带。在小麦收获后旋耕（25 cm）灭茬,整平播种。夏玉米生育期内根据土壤墒情采用微喷带统一喷灌,遇涝及时排水。统一采用病虫害预防方案进行病虫害防控。Table 1
表1
表1密度及肥料运筹
Table 1
| 处理 Treatment | 种植密度 Planting density (plant/hm2) | 行距 Row spacing | 肥料类型 Fertilizer | 肥料用量 Dosage (kg·hm-2) | 比例 Proportion | |||
|---|---|---|---|---|---|---|---|---|
| 播种 Seeding | 大喇叭口 V12 | 开花 VT | 乳熟 R3 | |||||
| SH | 82500 | 80+40 cm | 有机肥 Organic fertilizer | 7500 | 100% | |||
| N | 540 | 30%PU+10%U | 30%U | 20%U | 10%U | |||
| P2O5 | 180 | 100% | ||||||
| K2O | 360 | 75% | 25% | |||||
| HH | 82500 | 60+60 cm | 有机肥 Organic fertilizer | 7500 | 100% | |||
| N | 225 | 30%PU+10%U | 30%U | 20%U | 10%U | |||
| P2O5 | 150 | 100% | ||||||
| K2O | 300 | 75% | 25% | |||||
| FP | 67500 | 60+60 cm | 种肥同播三元复合肥（N-P2O5-K2O=14-16-15）750 kg·hm-2 Ternary compound fertilizer (N-P2O5-K2O=14-16-15) 750 kg·hm-2 | |||||
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1.3 测定项目与方法
1.3.1 地上部干物质积累量 玉米生长至拔节期（V6）、大喇叭口期（V12）、吐丝期（R1）、吐丝后30 d（R1+30 d）、成熟期（R6）时,取各处理内长势一致的玉米植株5株,将植株按茎秆、叶片、雌穗（穗轴和籽粒）、雄穗、苞叶分开,105℃杀青30 min,80℃烘至恒重并称重,计算不同生育时期群体干物质积累量。1.3.2 茎叶夹角、叶向值和叶面积指数 R1期分别于各小区选取长势一致的植株10株,穗位叶、穗位上叶及下叶为中部叶层,中部叶层以上为上部叶层,中部叶层以下为下部叶层。测量各层叶片叶长（Li）、沿叶片方向叶基部至叶片最高点的距离（Lf）,用量角器测量茎叶夹角,并计算叶向值（LOV）。
LOV=$\frac{\sum{i=1}{n} Qi(\frac{Lf}{Li})}{n}$
式中,θi为叶片与水平面夹角,Lf为沿叶片方向叶基部至叶片最高点的距离,Li为叶片伸直时长度,n为叶片数。
拔节期（V6）每个处理内选取长势一致的植株5株,定株。分别于V6、V12、R1、R1+30 d、R6期测量所选定植株绿叶的叶长、叶宽。单株叶面积（m2）=∑完全展开叶的叶长（m）×叶宽（m）×0.75+∑未完全展开叶的叶长（m）×叶宽（m）×0.5;叶面积指数（LAI）=（单株叶面积×单位面积株数）/占地面积。
1.3.3 群体冠层结构 采用大田切片法测定R1期群体冠层垂直结构[16],在每个处理内选取2 m2（1 m×2 m）内的植株,从基部起以40 cm为每层高度,按照层高分层割取样品,每层按照茎秆、叶片、雌穗、雄穗分样。在烘箱内105℃杀青30 min,80℃烘干至恒重,并称重。
1.3.4 冠层光能截获率 采用SunScan（Delta,英国）冠层分析仪,在玉米生长至R1期,选择晴朗无云的天气,于10：00—13：00测定各处理群体冠层内不同叶层及冠层顶部的光合有效辐射（PAR）。
光能截获率=PARi/TPAR×100%
式中,PARi为某叶层的PAR;TPAR为冠层顶部PAR。
1.3.5 叶绿体超微结构 在玉米R1期,在各处理中选取长势一致的植株,在其穗位叶片中段（避开叶脉）割取边长为0.5 cm的方形叶片,用3.3%戊二醛固定液（0.1 mol·L-1 pH 7.2的磷酸缓冲液配制）固定,抽真空,4℃下固定24 h。用磷酸缓冲盐溶液洗3次,每次20 min,再将材料转移到锇酸中,4℃固定4 h,用磷酸缓冲盐溶液冲洗3次。常规梯度（45%、55%、70%、85%、95%、100%）乙醇系列脱水,环氧丙烷置换。Epon812树脂包埋,70℃下聚合8 h,LKB-V型切片机切割超薄切片,经醋酸双氧铀和柠檬酸铅双重染色后,用日立-600 型透射电镜随机选取视野观察并拍照。
1.3.6 净光合速率 在玉米R1期,选择晴朗无云的天气,于9：00—11：00使用CIRAS-Ⅲ（PP System,美国）光合仪,每个处理选具有代表性植株10—15株,测定其穗位叶净光合速率（Pn）。
1.3.7 籽粒产量及产量构成因素 于玉米R6期,在每个处理内选取5个9 m2（5 m×1.8 m）具有代表性玉米带,将其全部果穗收获、晾晒,测定其产量和产量构成因素。
1.4 数据分析与作图
采用Microsoft Excel 2010进行数据处理;采用DPS进行数据统计分析,用LSD法做显著性分析（α=0.05）;用Sigmaplot 14.0作图。2 结果
2.1 不同栽培模式对夏玉米群体冠层结构的影响
栽培方式影响玉米叶片着生状态及生长发育,各叶层茎叶夹角均表现为FP＞SH＞HH,叶向值则表现为SH＞HH＞FP,SH和HH模式群体上部叶片上冲,利于中、下部叶片接收光能（表2）。全生育期内叶面积指数呈现先增大后降低的变化趋势,在吐丝期达到最大值,各个生育期内均表现为SH＞HH＞FP,在吐丝期后处理之间呈显著性差异（图2）。相比于FP模式,SH、HH模式群体中单位面积内干物质积累量显著提高;SH、HH模式群体内植株干重在120 cm以下的比例有显著增加,穗位叶及以下叶片的长势较好（图3）,2年试验不同处理间变化趋势一致。Table 2
Table 2Effects of different cultivation modes on the implantation status of summer maize
| 年份 Year | 处理 Treatment | 茎叶夹角 Stem-leaf angle (°) | 叶向值 Leaf orientation value | ||||
|---|---|---|---|---|---|---|---|
| 上层 Upper leave | 中层 Middle leave | 下层 Lower leave | 上层 Upper leave | 中层 Middle leave | 下层 Lower leave | ||
| 2018 | SH | 17.17ab | 24.01a | 25.35b | 69.72a | 62.51a | 54.08ab |
| HH | 16.58b | 19.75b | 23.17b | 69.59a | 61.64ab | 59.22a | |
| FP | 18.02a | 24.81a | 28.24a | 67.67b | 59.02b | 48.20b | |
| 2019 | SH | 11.88ab | 27.5ab | 33.7c | 75.41a | 54.57a | 46.57a |
| HH | 11.13b | 23.33b | 32.0c | 73.77ab | 54.17a | 44.86ab | |
| FP | 12.58a | 29.08a | 41.87a | 70.57b | 51.51ab | 33.83c | |
Values followed by different letters within a column are significantly different between treatments at P ＜ 0.05. The same as below
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图2
新窗口打开|下载原图ZIP|生成PPT图2不同栽培模式群体叶面积指数在各生育时期的变化 V6、V12、R1、R1+30、R6分别表示拔节期、大喇叭口期、吐丝期、吐丝后30 d、完熟期。
*和**分别表示在0.05和0.01水平上处理之间差异显著,ns表示处理之间差异不显著
Fig. 2Changes of leaf area index of populations in different cultivation modes at different growth stages V6, V12, R1, R1+30 and R6 represent jointing stage, 12 leaves stage, silking stage, 30 days after silking stage and maturation stage of summer maize.
* and ** indicate significantly different at P ＜ 0.05 and P ＜ 0.01, respectively, ns: No significance
图3
新窗口打开|下载原图ZIP|生成PPT图3不同栽培模式下夏玉米吐丝期冠层结构垂直分布
图中不同小写字母表示处理间差异达0.05显著水平
Fig. 3Vertical distribution of canopy structure of summer maize during silking stage under different cultivation modes Different small letters indicate significantly different between treatments at P ＜ 0.05
2.2 不同栽培模式夏玉米群体内光分布的差异
各冠层高度光能截获率均表现为SH＞HH＞FP,SH模式的光能截获率最大,漏光损失最小,HH模式次之,FP模式最易造成漏光损失,2年试验规律一致。2年试验SH、HH、FP模式中部叶层较上部叶层光能截获率分别平均增大39.67%、47.21%、45.04%,HH模式中、上部叶层结构最优（图4）。图4
新窗口打开|下载原图ZIP|生成PPT图4不同栽培模式群体光能截获率
U：上部叶层;M：中部叶层;D：下部叶层。同组数据后不同小写字母表示处理间差异达0.05显著水平。下同
Fig. 4Light energy interception rate of different cultivation modes
U: Upper leaf layer; M: Middle leaf layer; D: Lower leaf layer. Bars superscripted by different small letters are significantly different between treatments at P ＜ 0.05. The same as below
2.3 不同栽培模式对夏玉米叶绿体超微结构的影响
不同处理叶片叶绿体在外形上无明显差异,均为正常的“纺锤形”;SH、HH模式的叶绿体内部结构发育良好,FP模式发育相对较差。SH和HH模式的类囊体发育良好数目较多,基粒片层和基质片层排列整齐、清晰,细胞内膜结构完整;FP模式的叶绿体中类囊体发育相对较差,未发育完全的类囊体数目占比较大,且其基质片层模糊,且排列不齐（图5）。图5
新窗口打开|下载原图ZIP|生成PPT图5不同栽培模式群体内叶片叶绿体的发育状况
CM：叶绿体膜;GL：基粒片层;SL：基质片层。A、B、C分别为2018年超高产模式、高产高效模式、农户习惯管理模式;D、E、F分别为2019年超高产模式、高产高效模式、农户习惯管理模式
Fig. 5Development of leaf chloroplasts in different cultivation mode populations
CM: Chloroplast membrane; GL: Grana lamella; SL: Stroma lamella. A, B, and C are the super-high-yield mode, high-yield and efficient mode, and farmer management mode in 2018. D, E, and F are the super-high-yield mode, high-yield and efficient mode, and farmer management mode in 2019
2.4 不同栽培模式夏玉米穗位叶净光合速率的差异
夏玉米不同栽培模式的穗位叶吐丝期净光合速率表现为SH＞HH＞FP,且处理之间差异显著,2年大田试验呈现相同的变化趋势。2年试验中,SH模式较FP模式分别增大26.09%、24.34%;HH模式较FP模式分别增大15.07%、18.02%;SH模式较HH模式分别增大9.57%、5.48%（图6）。图6
新窗口打开|下载原图ZIP|生成PPT图6不同栽培模式中夏玉米穗位叶吐丝期净光合速率
Fig. 6Net photosynthetic rate of panicle leaves of summer maize during silking stage under different cultivation modes
2.5 不同栽培模式对夏玉米干物质积累量及产量的影响
不同栽培模式干物质积累量表现为SH＞HH＞FP。在2年试验中,干物质积累量SH、HH模式较FP模式平均增加27.74%、7.45%;对比玉米开花前、开花后干物质积累量的比例,与FP模式相比,SH、HH模式在开花后干物质积累量显著提高,SH、HH、FP模式干物质在吐丝后积累量占全生育期的比例分别为64.38%、60.03%、58.04%（表3）。SH、HH模式较FP模式可显著提高夏玉米籽粒产量,SH模式较FP模式平均增产14.20%,HH模式较FP模式平均增产4.91%。与FP模式相比,SH、HH模式的穗粒数及千粒重降低,单位面积穗数显著提高。SH、HH模式籽粒产量提高的主要原因是单位面积穗数的增加（表4）。Table 3
表3
表3不同栽培模式夏玉米干物质积累量及吐丝前后分配比例
Table 3
| 年份 Year | 处理 Treatment | 干物质积累量 Dry matter accumulation (kg·hm-2) | 干物质分配比例 Dry matter distribution ratio (%) | |||
|---|---|---|---|---|---|---|
| V6 | R1 | R6 | 吐丝前 Pre-silking | 吐丝后 Post-silking | ||
| 2018 | SH | 1842a | 9876a | 26885a | 36.73b | 63.27a |
| HH | 1793a | 9541b | 24214b | 39.41ab | 60.59ab | |
| FP | 1367b | 9226b | 22486c | 41.06a | 58.94b | |
| 2019 | SH | 1358a | 10111a | 29303a | 34.50b | 65.50a |
| HH | 1210b | 10019a | 24715b | 40.53a | 59.47b | |
| FP | 1193b | 9886a | 23069c | 42.85a | 57.15b | |
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Table 4
表4
表4不同栽培模式玉米籽粒产量及产量构成因素
Table 4
| 年份 Year | 处理 Treatment | 单位面积穗数 Ear number (ear·hm-2) | 穗粒数 Grains per ear | 千粒重 Thousand kernel weight (g) | 产量 Yield (t·hm-2) |
|---|---|---|---|---|---|
| 2018 | SH | 78495a | 513.5ab | 372.5b | 12.7a |
| HH | 74610a | 502.2b | 369.8b | 11.8b | |
| FP | 64478b | 547.3a | 385.1a | 11.6b | |
| 2019 | SH | 82560a | 474.4b | 377.8c | 13.2a |
| HH | 79892b | 454.2c | 384.5b | 12.0b | |
| FP | 67336c | 497.7a | 389.9a | 11.1c |
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3 讨论
叶片是植株进行光合作用的主要场所,是植物吸收、利用光能的最重要器官[19],叶面积指数是反映植株生长发育和光能利用率的重要指标,夏玉米要实现高产就要保持较高的叶面积指数[20,21,22,23],调节叶片着生状态和伸展方向,构建合理的冠层结构[21,24]。合理的冠层结构有利于叶片发育、形成适宜的群体内环境,可接收充足的光照,提高叶光合能力,从而提高干物质积累量及产量[25]。种植密度过高,上部叶片发育良好、生长健壮[26],导致植株间叶片相互遮荫[4],群体内光照不足,中下部叶片光能利用能力降低。适宜的肥料运筹、种植方式可调节植株生长发育状况[13,27],调整群体冠层结构使上层叶片上冲,群体内不同高度叶层的光照分布趋于合理化,保证叶片处于适宜的光环境[28],以提高光能利用率。本研究中,通过统筹各栽培措施构建的2种高产栽培模式,与农户生产模式相比具有较为合理的冠层结构。SH、HH模式叶面积指数显著大于FP模式,且具有更长的叶面积指数高值持续期（图2）。SH、HH模式群体上层叶片茎叶夹角小于FP模式、叶向值大于FP模式（表2）。对于120 cm以下叶片干物质积累量,SH模式显著大于FP模式,HH模式大于FP模式。SH、HH模式调节了上部叶片的着生状态,使上部叶片上冲,中下部叶层可接受充足的光能,既防止漏光损失、又减缓了高密植群体内叶片相互遮荫,SH模式中、下层叶片生长发育状况显著优于HH和FP模式,这是SH、HH模式可实现高产但增产水平不同的重要原因之一。叶绿体是叶片进行光合作用的主要细胞器,叶绿体超微结构与植株叶片光合性能密切相关。发育良好的叶绿体呈纺锤形,靠近细胞膜排布在细胞内,类囊体结构完整,叶绿体基粒数目增加、基粒片层和基质片层排列紧密[29]。当受光不足时,叶片细胞及叶绿体结构会被破坏,导致光合系统受损,从而影响光合性能[18,30]。施用适量的氮、钾肥可保持番茄[31]、甘蔗[32]的叶绿体超微结构。在本研究中,SH、HH模式的叶绿体内部结构发育良好,FP模式发育相对较差。SH和HH模式的类囊体发育良好且数目较多,基粒片层和基质片层排列整齐、清晰,细胞内膜结构完整;FP模式的叶绿体类囊体发育相对较差,未发育完全的比例较高,基质片层模糊且排列不齐（图5）。进一步说明SH、HH模式2个群体冠层结构适宜,群体内光环境良好,未造成叶片之间相互遮荫影响叶绿体结构发育,而且SH、HH模式的叶绿体结构更有利于进行光合作用。HH模式的叶绿体结构发育良好,但其净光合速率显著低于SH模式,这可能与光合相关酶的活性有关。
与农户生产模式相比,通过优化种植密度和肥料运筹等措施构建的超高产模式和高产高效模式可显著促进根系发育、提高氮肥利用率[14]和光能生产效率[15]。本试验结果表明,超高产模式和高产高效模式可实现增产的原因是优化了群体冠层结构,促进植株及叶绿体结构的发育,延缓叶片衰老,提高了叶片光合能力。
4 结论
相比于农户习惯管理模式,超高产模式、高产高效模式实现产量提高的原因是优化了群体冠层结构,促进叶片的发育,保证叶绿体结构的完整性,显著提高了叶片光合能力。与超高产模式相比,高产高效模式减小肥料施用量,其群体结构适宜且叶片发育良好,是更有助于利用光能的栽培模式。参考文献 原文顺序
文献年度倒序
文中引用次数倒序
被引期刊影响因子
DOI:10.3864/j.issn.0578-1752.2017.11.001URL [本文引用: 1]
Maize is the first major crop in China and in the world, it plays an important role in ensuring China’s food security. At present, in the face of the rapid development of economic society and a series of problems such as population growth and land reduction, resources shortage and ecological environment deterioration, maize cultivation science is facing new historic opportunities and challenges. In this crucial historical juncture, it is of great significance to review the scientific research and technical progress of maize cultivation in China and to explore the future development direction. Analysis shows that, the aim of maize cultivation research has been transformed from yield production to collaborative development of high yield, high quality, high efficiency, eco-friendly, security and other goals after 60 years of efforts. The research contents were gradually widened and further deepened with remarkable Chinese characteristics. Since entering into the 21th century, the research of maize cultivation has entered a golden development stage. In this stage, a series of breakthroughs in maize cultivation theory, key technology innovation and application have been achieved, which have taken a positive role in ensuring China’s food security. According to the demand of maize production for science and technology in the future and the development trend of modern science and technology, this article indicated that, in the future, high quality, high efficiency, eco-friendly, security will still be the main objectives of maize cultivation. In this article, the key directions and tasks of maize cultivation research in the next 20 years were put forward: (1) Continue to explore the potential of maize yield in different ecological areas and technologies that can realize these potentials, and make every effort to raise the level of yield per unit; (2) Transform the mode of production and take the improving efficiency of resource utilization and labor productivity as goals, reduce the production costs, improve product quality and the market competitiveness of maize; to develop silage and fresh maize so as to promote the diversified development of maize production; (3) In order to respond to the global climate change, carry out the theoretical and technological researches on yield stability and anti-disaster to realize the sustainable production of maize; (4) Based on modern information technology to carry out the researches of intelligent cultivation technology to achieve maize precise production and management; (5) Strengthen the basic researches of maize cultivation and tamp the researches on maize science and technology and the basement of maize production.
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DOI:10.3864/j.issn.0578-1752.2017.11.001URL [本文引用: 1]
Maize is the first major crop in China and in the world, it plays an important role in ensuring China’s food security. At present, in the face of the rapid development of economic society and a series of problems such as population growth and land reduction, resources shortage and ecological environment deterioration, maize cultivation science is facing new historic opportunities and challenges. In this crucial historical juncture, it is of great significance to review the scientific research and technical progress of maize cultivation in China and to explore the future development direction. Analysis shows that, the aim of maize cultivation research has been transformed from yield production to collaborative development of high yield, high quality, high efficiency, eco-friendly, security and other goals after 60 years of efforts. The research contents were gradually widened and further deepened with remarkable Chinese characteristics. Since entering into the 21th century, the research of maize cultivation has entered a golden development stage. In this stage, a series of breakthroughs in maize cultivation theory, key technology innovation and application have been achieved, which have taken a positive role in ensuring China’s food security. According to the demand of maize production for science and technology in the future and the development trend of modern science and technology, this article indicated that, in the future, high quality, high efficiency, eco-friendly, security will still be the main objectives of maize cultivation. In this article, the key directions and tasks of maize cultivation research in the next 20 years were put forward: (1) Continue to explore the potential of maize yield in different ecological areas and technologies that can realize these potentials, and make every effort to raise the level of yield per unit; (2) Transform the mode of production and take the improving efficiency of resource utilization and labor productivity as goals, reduce the production costs, improve product quality and the market competitiveness of maize; to develop silage and fresh maize so as to promote the diversified development of maize production; (3) In order to respond to the global climate change, carry out the theoretical and technological researches on yield stability and anti-disaster to realize the sustainable production of maize; (4) Based on modern information technology to carry out the researches of intelligent cultivation technology to achieve maize precise production and management; (5) Strengthen the basic researches of maize cultivation and tamp the researches on maize science and technology and the basement of maize production.
DOI:10.3724/SP.J.1006.2012.00080URL [本文引用: 1]
Maize high-yield potential and small-area super-high yield research in different areas were conducted in 2006–2010. The geographical distribution, yield components and key culture techniques of 159 maize super-high yield plots with yield of ≥15 000 kg ha-1 were analyzed comprehensively. Results showed that: (1) most high-yield plots distributed in higher latitude (40°–43°N) and higher elevation regions (1 000–1 500 m) with abundant sunlight and higher temperature in the daytime and lower temperature in the nighttime which were the primary factors affected super-high yield; (2) the yield structure was 88 950 ears ha-1, 541 kernels per ear, 360.0 g per 1000-kernel, 191.8 g per ear, and the average yield was 16 692 kg ha-1;the ear and kernel numbers among yield components were correlated significantly with yield; (3) the key culture techniques for maize high-yield was selecting high density tolerant maize cultivar combined with reasonable dense planting, abundant water and fertilizer supply, scientific management, and film mulching.
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DOI:10.3724/SP.J.1006.2012.00080URL [本文引用: 1]
Maize high-yield potential and small-area super-high yield research in different areas were conducted in 2006–2010. The geographical distribution, yield components and key culture techniques of 159 maize super-high yield plots with yield of ≥15 000 kg ha-1 were analyzed comprehensively. Results showed that: (1) most high-yield plots distributed in higher latitude (40°–43°N) and higher elevation regions (1 000–1 500 m) with abundant sunlight and higher temperature in the daytime and lower temperature in the nighttime which were the primary factors affected super-high yield; (2) the yield structure was 88 950 ears ha-1, 541 kernels per ear, 360.0 g per 1000-kernel, 191.8 g per ear, and the average yield was 16 692 kg ha-1;the ear and kernel numbers among yield components were correlated significantly with yield; (3) the key culture techniques for maize high-yield was selecting high density tolerant maize cultivar combined with reasonable dense planting, abundant water and fertilizer supply, scientific management, and film mulching.
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DOI:10.1007/s13580-016-0133-6URL [本文引用: 1]
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DOI:10.1093/jxb/ert389URL [本文引用: 3]
Plants compete with neighbouring vegetation for limited resources. In competition for light, plants adjust their architecture to bring the leaves higher in the vegetation where more light is available than in the lower strata. These architectural responses include accelerated elongation of the hypocotyl, internodes and petioles, upward leaf movement (hyponasty), and reduced shoot branching and are collectively referred to as the shade avoidance syndrome. This review discusses various cues that plants use to detect the presence and proximity of neighbouring competitors and respond to with the shade avoidance syndrome. These cues include light quality and quantity signals, mechanical stimulation, and plant-emitted volatile chemicals. We will outline current knowledge about each of these signals individually and discuss their possible interactions. In conclusion, we will make a case for a whole-plant, ecophysiology approach to identify the relative importance of the various neighbour detection cues and their possible interactions in determining plant performance during competition.
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[本文引用: 1]
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[本文引用: 1]
DOI:10.3724/SP.J.1006.2018.01867URL [本文引用: 1]
Light intensity plays a significant role in determining the growth and seed yield of crops under the sheltering of intercropping systems. By setting different light intensities, the photosynthetic characteristics, assimilate metabolism and the diurnal variation of chloroplast ultrastructure in leaf of different soybean cultivars to clarify the effect of light intensity on the structure of soybean leaf and the accumulation of carbohydrate, in order to provide a theoretical basis for improving soybean yield and quality. A pot experiment was carried out with three light intensities treatments, including CK (normal light, shading 0), A1 (black shading net, shading 10%) and A2 (two black shading nets, shading 36%) of two soybean cultivars (shade-resistant cultivar Nandou-12 and shade susceptible cultivar Guixia-3). With increased shading, net photosynthetic rate, stomatal conductance, transpiration rate and biomass decreased while intercellular carbon dioxide concentration and chlorophyll b increased in all treatments. There was a significant difference in the diurnal variation of sucrose and starch contents in soybean leaf under the same treatment. The diurnal variation of sucrose content in soybean leaf showed a bimodal curve with the peaks at 16:00 and next day 6:00 respectively under CK and A1 treatment. Under A2 treatment, the highest diurnal sucrose content was 32.80 μg g -1 in Nandou 12 and showed a unimodal changing trend with the peak at 16:00. The diurnal variation of starch content showed a single-peak curve and the highest value appeared at 21:00. Compared with the shade sensitive cultivar, the shade-tolerant soybean had greater diurnal variation of sucrose content and starch content under A2 treatment. The chloroplast structure of soybean leaf was intact and unbroken under the low light treatment. The diurnal variation of the cross-sectional area ratio of starch grain to chloroplast in the same cultivar changed significantly under the same treatment, showing a trend of decreasing after increasing. The changing rate was greater in shade-tolerant cultivar than in sensitive cultivar, and the maximum value appeared at 21:00. Therefore, biomass accumulation of soybean leaves and photosynthesis decreased with increasing shading. However, shade-tolerant cultivar maintained a good photosynthesis by adjusting the diurnal variation of photosynthetic organ structure, thus better adapting to the moderate shading condition.
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DOI:10.3724/SP.J.1006.2018.01867URL [本文引用: 1]
Light intensity plays a significant role in determining the growth and seed yield of crops under the sheltering of intercropping systems. By setting different light intensities, the photosynthetic characteristics, assimilate metabolism and the diurnal variation of chloroplast ultrastructure in leaf of different soybean cultivars to clarify the effect of light intensity on the structure of soybean leaf and the accumulation of carbohydrate, in order to provide a theoretical basis for improving soybean yield and quality. A pot experiment was carried out with three light intensities treatments, including CK (normal light, shading 0), A1 (black shading net, shading 10%) and A2 (two black shading nets, shading 36%) of two soybean cultivars (shade-resistant cultivar Nandou-12 and shade susceptible cultivar Guixia-3). With increased shading, net photosynthetic rate, stomatal conductance, transpiration rate and biomass decreased while intercellular carbon dioxide concentration and chlorophyll b increased in all treatments. There was a significant difference in the diurnal variation of sucrose and starch contents in soybean leaf under the same treatment. The diurnal variation of sucrose content in soybean leaf showed a bimodal curve with the peaks at 16:00 and next day 6:00 respectively under CK and A1 treatment. Under A2 treatment, the highest diurnal sucrose content was 32.80 μg g -1 in Nandou 12 and showed a unimodal changing trend with the peak at 16:00. The diurnal variation of starch content showed a single-peak curve and the highest value appeared at 21:00. Compared with the shade sensitive cultivar, the shade-tolerant soybean had greater diurnal variation of sucrose content and starch content under A2 treatment. The chloroplast structure of soybean leaf was intact and unbroken under the low light treatment. The diurnal variation of the cross-sectional area ratio of starch grain to chloroplast in the same cultivar changed significantly under the same treatment, showing a trend of decreasing after increasing. The changing rate was greater in shade-tolerant cultivar than in sensitive cultivar, and the maximum value appeared at 21:00. Therefore, biomass accumulation of soybean leaves and photosynthesis decreased with increasing shading. However, shade-tolerant cultivar maintained a good photosynthesis by adjusting the diurnal variation of photosynthetic organ structure, thus better adapting to the moderate shading condition.
DOI:10.3724/SP.J.1006.2018.01032URL [本文引用: 1]
DOI:10.3724/SP.J.1006.2018.01032URL [本文引用: 1]
DOI:10.3864/j.issn.0578-1752.2016.02.011URL [本文引用: 1]
Rice production, especially of good quality, must be increased to feed the world’s growing population in the future. Meanwhile, water scarcity and nitrogen over-fertilization is threatening rice production of irrigated region because of fresh water and fertilizer nitrogen crises. Therefore, a major challenge in rice production is to save both water and fertilizer nitrogen while increasing grain yield and improving quality characteristics. Rice production must synchronously focus on high grain yield and good-quality when rice is planted under both water and nitrogen saving cultivation. In brief, rice production and sustainable development are considered not only for high yield and good quality, but also to ensure high water/nitrogen use efficiencies. Based on this background, the paper reviews (1) the effect of water regimes, nitrogen managements, and water-nitrogen interaction managements on grain yield, water/nitrogen use efficiencies, and grain quality of rice plants, respectively; (2) eco-physiological mechanisms obtaining high-yielding and good quality with high water/nitrogen use efficiencies when irrigated rice plants are managed in different water treatments, nitrogen treatments, and water-nitrogen interaction treatments. Finally, some potential research points including theory and technology researches, which could increase yield and improve quality of rice plants with high resources (water and nitrogen ) use efficiencies, were presented in this review.
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DOI:10.3864/j.issn.0578-1752.2016.02.011URL [本文引用: 1]
Rice production, especially of good quality, must be increased to feed the world’s growing population in the future. Meanwhile, water scarcity and nitrogen over-fertilization is threatening rice production of irrigated region because of fresh water and fertilizer nitrogen crises. Therefore, a major challenge in rice production is to save both water and fertilizer nitrogen while increasing grain yield and improving quality characteristics. Rice production must synchronously focus on high grain yield and good-quality when rice is planted under both water and nitrogen saving cultivation. In brief, rice production and sustainable development are considered not only for high yield and good quality, but also to ensure high water/nitrogen use efficiencies. Based on this background, the paper reviews (1) the effect of water regimes, nitrogen managements, and water-nitrogen interaction managements on grain yield, water/nitrogen use efficiencies, and grain quality of rice plants, respectively; (2) eco-physiological mechanisms obtaining high-yielding and good quality with high water/nitrogen use efficiencies when irrigated rice plants are managed in different water treatments, nitrogen treatments, and water-nitrogen interaction treatments. Finally, some potential research points including theory and technology researches, which could increase yield and improve quality of rice plants with high resources (water and nitrogen ) use efficiencies, were presented in this review.
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DOI:10.2134/agronj2002.1317URL [本文引用: 1]
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[本文引用: 1]
DOI:10.3724/SP.J.1006.2010.01226URL [本文引用: 1]
With different plant population densities (6.75´104, 9.00´104, and 11.25´104 plants ha-1), the effects of the deneity and row spacing on grain yield and canopy apparent photosynthesis were studied in this article. The results were as follows: with the increase of planting density, grain yield, leaf area index (LAI) and capture efficiency of photosynthestically active radiation(PAR) in upper leaf layer, as well as canopy apparent photosynthesis (CAP) and canopy respiration (CR) and dry matter quantity increased accordantly; but, chlorophyll content and capture efficiency of PAR in the middle and lower layers of canopy decreased. Within different row spacing treatments, the wide-narrow row spacing were not superior to the uniform one significantly at 6.75´104 plants ha-1. However, at 9.00´104 and 11.25´104 plants ha-1, grain yield, LAI, chlorophyll content, capture efficiency of PAR in middle leaf layer and average rate of CAP after anthesis in row spacing of “80 cm+40 cm” were remarkably higher than those in other three row spacings (uniform, 70 cm + 50 cm, 90 cm + 30 cm); while CR/TCAP (ratio of canopy respiration to total canopy apparent photosynthesis) in row spacing of ’80 cm+40 cm’ was the lowest, compared to the others. From the above, it was suggested that at higher plant density the row spacing of ’80 cm+40 cm’ could enlarge photosynthetic area, enhance PAR in middle leaf layer, increase CAP, reduce CR and improve grain yield.
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DOI:10.3724/SP.J.1006.2010.01226URL [本文引用: 1]
With different plant population densities (6.75´104, 9.00´104, and 11.25´104 plants ha-1), the effects of the deneity and row spacing on grain yield and canopy apparent photosynthesis were studied in this article. The results were as follows: with the increase of planting density, grain yield, leaf area index (LAI) and capture efficiency of photosynthestically active radiation(PAR) in upper leaf layer, as well as canopy apparent photosynthesis (CAP) and canopy respiration (CR) and dry matter quantity increased accordantly; but, chlorophyll content and capture efficiency of PAR in the middle and lower layers of canopy decreased. Within different row spacing treatments, the wide-narrow row spacing were not superior to the uniform one significantly at 6.75´104 plants ha-1. However, at 9.00´104 and 11.25´104 plants ha-1, grain yield, LAI, chlorophyll content, capture efficiency of PAR in middle leaf layer and average rate of CAP after anthesis in row spacing of “80 cm+40 cm” were remarkably higher than those in other three row spacings (uniform, 70 cm + 50 cm, 90 cm + 30 cm); while CR/TCAP (ratio of canopy respiration to total canopy apparent photosynthesis) in row spacing of ’80 cm+40 cm’ was the lowest, compared to the others. From the above, it was suggested that at higher plant density the row spacing of ’80 cm+40 cm’ could enlarge photosynthetic area, enhance PAR in middle leaf layer, increase CAP, reduce CR and improve grain yield.
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DOI:10.2134/agronj2016.11.0675URL [本文引用: 2]
DOI:10.3864/j.issn.0578-1752.2017.12.008URL [本文引用: 2]
【Objective】The objective of this study was to promote the growth of maize roots, enhance root absorption performance, and then reduce the amount of fertilizer, and then provide a theoretical basis for promoting the production of high yield and high efficiency by investigating the effects of different cultivation patterns on the root performance, grain yield formation and nitrogen uptake and utilization of summer maize, and exploring the relationship between root morphological characteristics and nitrogen uptake capacity of maize under different cultivation patterns. 【Method】Under two soil fertilities, with no nitrogen treatment as control (CK), three cultivation patterns including super high-yielding cultivation pattern (SH), high-yielding and high efficiency cultivation pattern (HH) and local farmer's practice(FP) in the long-term experiments by using ZD958 as testing varieties. The regulation of root characteristics on yield formation and nitrogen utilization in summer maize under different cultivation patterns were measured in fixed field experiment. 【Result】The yields of summer maize was significantly different among different cultivation patterns, compared with the HH, FP and CK patterns, the average yield of SH pattern in two years both in high soil fertility (HSF) and low soil fertility (LSF) were increased by 3.54%, 17.50%, 30.12% and 3.16%, 18.45%, 27.72% respectively. Multivariate analysis showed that both soil fertility and cultivation patterns had significant effects on summer maize yield, and comprehensive effect of double factors varied by years. The population biomass in high and low soil fertilities was SH > HH > FP > CK during the whole growing season. The total nitrogen accumulation in SH pattern was significantly higher than those in other patterns at the VT and R6 stages, and the N use efficiency and agronomic N use efficiency were higher than that of FP. HH pattern had the highest agronomic N use efficiency, nutrient use efficiency and nitrogen harvest index. Its nitrogen partial factor productivity was lower than FP, but still higher than the SH pattern. The results showed that summer maize root growth was greatly affected by different cultivation patterns. Root dry weight density, root length density and root surface area density were all expressed as SH > HH > FP > CK. From V12 to VT stage, increases in root length, root dry weight and root surface density of SH and HH patterns were higher than that of FP pattern, and decreases in that of FP pattern were highest from VT to R3 stage. The proportion of active absorption area of SH and HH patterns at VT stage was significantly higher than that in FP pattern. The root length density, root surface area density, root dry weight density were very significantly and positively correlated with yield and nitrogen use efficiency. 【Conclusion】HH pattern effectively promoted root development, delayed the senescence of root, improved the nitrogen use efficiency, achieved the high yield and high efficiency of summer maize.
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DOI:10.3864/j.issn.0578-1752.2017.12.008URL [本文引用: 2]
【Objective】The objective of this study was to promote the growth of maize roots, enhance root absorption performance, and then reduce the amount of fertilizer, and then provide a theoretical basis for promoting the production of high yield and high efficiency by investigating the effects of different cultivation patterns on the root performance, grain yield formation and nitrogen uptake and utilization of summer maize, and exploring the relationship between root morphological characteristics and nitrogen uptake capacity of maize under different cultivation patterns. 【Method】Under two soil fertilities, with no nitrogen treatment as control (CK), three cultivation patterns including super high-yielding cultivation pattern (SH), high-yielding and high efficiency cultivation pattern (HH) and local farmer's practice(FP) in the long-term experiments by using ZD958 as testing varieties. The regulation of root characteristics on yield formation and nitrogen utilization in summer maize under different cultivation patterns were measured in fixed field experiment. 【Result】The yields of summer maize was significantly different among different cultivation patterns, compared with the HH, FP and CK patterns, the average yield of SH pattern in two years both in high soil fertility (HSF) and low soil fertility (LSF) were increased by 3.54%, 17.50%, 30.12% and 3.16%, 18.45%, 27.72% respectively. Multivariate analysis showed that both soil fertility and cultivation patterns had significant effects on summer maize yield, and comprehensive effect of double factors varied by years. The population biomass in high and low soil fertilities was SH > HH > FP > CK during the whole growing season. The total nitrogen accumulation in SH pattern was significantly higher than those in other patterns at the VT and R6 stages, and the N use efficiency and agronomic N use efficiency were higher than that of FP. HH pattern had the highest agronomic N use efficiency, nutrient use efficiency and nitrogen harvest index. Its nitrogen partial factor productivity was lower than FP, but still higher than the SH pattern. The results showed that summer maize root growth was greatly affected by different cultivation patterns. Root dry weight density, root length density and root surface area density were all expressed as SH > HH > FP > CK. From V12 to VT stage, increases in root length, root dry weight and root surface density of SH and HH patterns were higher than that of FP pattern, and decreases in that of FP pattern were highest from VT to R3 stage. The proportion of active absorption area of SH and HH patterns at VT stage was significantly higher than that in FP pattern. The root length density, root surface area density, root dry weight density were very significantly and positively correlated with yield and nitrogen use efficiency. 【Conclusion】HH pattern effectively promoted root development, delayed the senescence of root, improved the nitrogen use efficiency, achieved the high yield and high efficiency of summer maize.
DOI:10.3864/j.issn.0578-1752.2019.08.006URL [本文引用: 2]
【Objective】 In the present study, the biomass production and resource availability among yield levels were studied to quantify the gap of yield, radiation production efficiency and temperature production efficiency of summer maize in Shandong province. This study aimed to clarify the contribution rate of agricultural production conditions and cultivation measures to yield gap and efficiency gap, and to explore the possibility of synergistic narrow the yield gap and efficiency gap, so as to provide a theoretical basis for closing yield gap and improving resource utilization efficiency. 【Method】 The experiment was conducted in Taian, Zibo and Yantai in Shandong province from 2017 to 2018. Based on the investigation of summer maize production in Shandong province, four management models were designed in consideration of appropriate increase of plant density, optimization of fertilizer and water, increase of yield and efficiency with the same integrated management. The four yield levels, including super high yield (SH), high yield and high efficiency (HH), farmer level (FP) and basic production level (CK), were simulated. And the gap of yield, radiation production efficiency and temperature production efficiency of different yield levels were analyzed. With the integrative analysis of radiation-temperature production potential and crop yield performance, the factors affecting gap of yield and efficiency and the way closing yield gap and increasing efficiency were explored in the present study. 【Result】 At present, the yield gap between radiation temperature potential level and super high yield level, super high yield level and high yield high efficiency level, high yield and high efficiency level and farmer production level, farmer production level and basic production level of summer maize in Shandong province were 5.85, 0.82, 1.90 and 1.35 t·hm -2, respectively; The radiation production efficiency gap were 1.74, 0.15, 0.28 and 0.45 g·MJ -1, respectively; and the temperature production efficiency gap were 1.09, 0.10, 0.17 and 0.28 kg·hm -2·℃ -1, respectively. The current uncontrollable factors contributed 58.49% to yield gap, and contributed 66.09% to light and temperature production efficiency. And geographical difference factors contributed 1.98% to yield gap, contributed 2.49% to radiation production efficiency, and contributed 3.24% to temperature production efficiency. There was a significant correlation between the yield gap and the production efficiency gap. SH and HH had higher biomass, mean leaf area index (MLAI) and canopy light energy interception rate than FP and CK. 【Conclusion】 At present, the gap of yield, the radiation production efficiency, and the temperature production efficiency between the farmer production level and the radiation temperature potential level of summer maize in Shandong province were 8.56 t·hm -2, 2.17 g·MJ -1, and 1.35 kg·hm -2·℃ -1, respectively, so there was room for improvement in yield and utilization efficiency of radiation and temperature resources. There was a significant correlation between the yield gap and the production efficiency gap, on the basis of existing farmer management measures, the application of high-yield and high-efficiency management mode (increase the plant density of 15 000 plant·hm -2, and increasing the amount of fertilization appropriately, changing the one-time fertilization into the sub-fertilization mode with water and fertilizer integration during the stage of sowing, spike formation, flowering, and milking) could narrow the yield gap by 1.90 t·hm -2and increase the production efficiency of radiation and temperature resources by 14.74% and 14.41%, respectively, which was an effective technical way to synergistic close yield gap and increase efficiency.
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DOI:10.3864/j.issn.0578-1752.2019.08.006URL [本文引用: 2]
【Objective】 In the present study, the biomass production and resource availability among yield levels were studied to quantify the gap of yield, radiation production efficiency and temperature production efficiency of summer maize in Shandong province. This study aimed to clarify the contribution rate of agricultural production conditions and cultivation measures to yield gap and efficiency gap, and to explore the possibility of synergistic narrow the yield gap and efficiency gap, so as to provide a theoretical basis for closing yield gap and improving resource utilization efficiency. 【Method】 The experiment was conducted in Taian, Zibo and Yantai in Shandong province from 2017 to 2018. Based on the investigation of summer maize production in Shandong province, four management models were designed in consideration of appropriate increase of plant density, optimization of fertilizer and water, increase of yield and efficiency with the same integrated management. The four yield levels, including super high yield (SH), high yield and high efficiency (HH), farmer level (FP) and basic production level (CK), were simulated. And the gap of yield, radiation production efficiency and temperature production efficiency of different yield levels were analyzed. With the integrative analysis of radiation-temperature production potential and crop yield performance, the factors affecting gap of yield and efficiency and the way closing yield gap and increasing efficiency were explored in the present study. 【Result】 At present, the yield gap between radiation temperature potential level and super high yield level, super high yield level and high yield high efficiency level, high yield and high efficiency level and farmer production level, farmer production level and basic production level of summer maize in Shandong province were 5.85, 0.82, 1.90 and 1.35 t·hm -2, respectively; The radiation production efficiency gap were 1.74, 0.15, 0.28 and 0.45 g·MJ -1, respectively; and the temperature production efficiency gap were 1.09, 0.10, 0.17 and 0.28 kg·hm -2·℃ -1, respectively. The current uncontrollable factors contributed 58.49% to yield gap, and contributed 66.09% to light and temperature production efficiency. And geographical difference factors contributed 1.98% to yield gap, contributed 2.49% to radiation production efficiency, and contributed 3.24% to temperature production efficiency. There was a significant correlation between the yield gap and the production efficiency gap. SH and HH had higher biomass, mean leaf area index (MLAI) and canopy light energy interception rate than FP and CK. 【Conclusion】 At present, the gap of yield, the radiation production efficiency, and the temperature production efficiency between the farmer production level and the radiation temperature potential level of summer maize in Shandong province were 8.56 t·hm -2, 2.17 g·MJ -1, and 1.35 kg·hm -2·℃ -1, respectively, so there was room for improvement in yield and utilization efficiency of radiation and temperature resources. There was a significant correlation between the yield gap and the production efficiency gap, on the basis of existing farmer management measures, the application of high-yield and high-efficiency management mode (increase the plant density of 15 000 plant·hm -2, and increasing the amount of fertilization appropriately, changing the one-time fertilization into the sub-fertilization mode with water and fertilizer integration during the stage of sowing, spike formation, flowering, and milking) could narrow the yield gap by 1.90 t·hm -2and increase the production efficiency of radiation and temperature resources by 14.74% and 14.41%, respectively, which was an effective technical way to synergistic close yield gap and increase efficiency.
[本文引用: 2]
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[本文引用: 1]
DOI:10.13287/j.1001-9332.201803.021URLPMID:29722231 [本文引用: 2]
We examined the changes of photosynthetic characteristics and chloroplast ultrastructure in mesophyll cell of summer maize in response to different light intensities in the field, with the summer maize hybrid Denghai 605 as experimental material. Two treatments of both shading (S) and increasing light (L) from flowering to physiological maturity stage were designed, with the ambient sunlight treatment as control (CK). Under shading treatment, poorly developed thylakoid structure, blurry lamellar structure, loose granum, large gap between slices and warping granum were the major characteristics in chloroplast. Meanwhile, photosynthetic rate (Pn), transpiration rate, stomatal conductance, chlorophyll content, and actual photo-chemical efficiency (PhiPSII) decreased, whereas the maximal photochemical efficiency and non-photochemical quenching increased, which resulted in decreases in grain yield under shading treatment. However, a better development was observed in chloroplasts for L treatment, with the number of grana and lamellae increased and lamellae arranged compactly. In addition, Pn and PhiPSII increased under L treatment, which increased grain yield. The chloroplast arrangement dispersed in mesophyll cells and chloroplast ultrastructure was destroyed after shading, and then chlorophyll synthesis per unit leaf area and photosynthetic capacity decreased. In contrast, the number of grana and lamellae increased and lamellae arranged compactly after increasing light, which are beneficial for corn yield.
DOI:10.13287/j.1001-9332.201803.021URLPMID:29722231 [本文引用: 2]
We examined the changes of photosynthetic characteristics and chloroplast ultrastructure in mesophyll cell of summer maize in response to different light intensities in the field, with the summer maize hybrid Denghai 605 as experimental material. Two treatments of both shading (S) and increasing light (L) from flowering to physiological maturity stage were designed, with the ambient sunlight treatment as control (CK). Under shading treatment, poorly developed thylakoid structure, blurry lamellar structure, loose granum, large gap between slices and warping granum were the major characteristics in chloroplast. Meanwhile, photosynthetic rate (Pn), transpiration rate, stomatal conductance, chlorophyll content, and actual photo-chemical efficiency (PhiPSII) decreased, whereas the maximal photochemical efficiency and non-photochemical quenching increased, which resulted in decreases in grain yield under shading treatment. However, a better development was observed in chloroplasts for L treatment, with the number of grana and lamellae increased and lamellae arranged compactly. In addition, Pn and PhiPSII increased under L treatment, which increased grain yield. The chloroplast arrangement dispersed in mesophyll cells and chloroplast ultrastructure was destroyed after shading, and then chlorophyll synthesis per unit leaf area and photosynthetic capacity decreased. In contrast, the number of grana and lamellae increased and lamellae arranged compactly after increasing light, which are beneficial for corn yield.
URL [本文引用: 1]
【Objective】It is very important to study photosynthesis of super high-yielding maize hybrids, so a field trail was conducted to research the relation to photosynthetic traits and yield of over-15000 kg ha-1 summer maize hybrids during grain filling period. 【Method】Three summer maize hybrids (XY335, DH3632 and DH3806) were planted at 78000 plants ha-1 in National Corn Project Technology Research Center (Shandong) randomly. Above-ground biomass partitioning and photosynthetic characteristics of ear leaves were investigated to evaluate yield formation of three super high-yielding maize hybrids during grain filling period.【Result】Yields of three-type maize hybrids were over 15000 kg ha-1, and yield of XY335 was higher than that of DH3632 and DH3806 significantly (P＜0.05). Characteristic of grain filling analyzed by Richards equation showed XY335 had the higher grain-filling rate, the longer active growing period, and it reached the maximum grain-filling rate earlier than DH3632 and DH3806. The result indicated grain-filling traits like XY335 was favorable to high yield in the experiment. The leaves’ photosynthetic physiology quantity of XY335 was highest of the three-type hybrids. XY335 had high net photosynthetic rate (Pn), PEPCase activity, RuBPCase activity and chlorophyll a/b value after anthesis, and the leaf area index (LAI) and soluble protein content decreased slowly from 20d and 30d after flowering, respectively. 【Conclusion】To obtain 15000 kg ha-1 of super high-yielding breeding and cultivation in practice, we need to improve the leaves photosynthetic physiology quantity to maintain high grain-filling rate and long active growing period after anthesis, enhance the solar energy use efficiency.
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URL [本文引用: 1]
【Objective】It is very important to study photosynthesis of super high-yielding maize hybrids, so a field trail was conducted to research the relation to photosynthetic traits and yield of over-15000 kg ha-1 summer maize hybrids during grain filling period. 【Method】Three summer maize hybrids (XY335, DH3632 and DH3806) were planted at 78000 plants ha-1 in National Corn Project Technology Research Center (Shandong) randomly. Above-ground biomass partitioning and photosynthetic characteristics of ear leaves were investigated to evaluate yield formation of three super high-yielding maize hybrids during grain filling period.【Result】Yields of three-type maize hybrids were over 15000 kg ha-1, and yield of XY335 was higher than that of DH3632 and DH3806 significantly (P＜0.05). Characteristic of grain filling analyzed by Richards equation showed XY335 had the higher grain-filling rate, the longer active growing period, and it reached the maximum grain-filling rate earlier than DH3632 and DH3806. The result indicated grain-filling traits like XY335 was favorable to high yield in the experiment. The leaves’ photosynthetic physiology quantity of XY335 was highest of the three-type hybrids. XY335 had high net photosynthetic rate (Pn), PEPCase activity, RuBPCase activity and chlorophyll a/b value after anthesis, and the leaf area index (LAI) and soluble protein content decreased slowly from 20d and 30d after flowering, respectively. 【Conclusion】To obtain 15000 kg ha-1 of super high-yielding breeding and cultivation in practice, we need to improve the leaves photosynthetic physiology quantity to maintain high grain-filling rate and long active growing period after anthesis, enhance the solar energy use efficiency.
DOI:10.3864/j.issn.0578-1752.2011.21.005URL [本文引用: 1]
【Objective】 Canopy structure and canopy functional characteristics of super-high yield spring maize populations were studied to reveal the physiological mechanism of formation of super-high yield, which provided a theoretical basis for cultivation of super-high yield spring maize.【Method】The Jinshan 27 was grown under super-high-yield cultivation (SHY) and normal high-yield cultivation (CK) condition in 2009 and 2010 to assess the indexes of canopy structure and physiological characteristics of super-high yield maize.【Result】Compared with normal high-yield cultivation, the super-high yield spring maize had higher leaf area index (LAI), and three-ear leaves was more obvious after silking stage. Leaf angle of different leaf locations was lower and the leaf direction value was higher than normal high-yield cultivation, and particularly in the three-ear. With the process of the growing period, the difference of photosynthetic potential between the super-high-yield cultivation and the normal high-yield cultivation increased. In the silking stage and milking stage, the difference of the net photosynthetic rate of two cultivation modes was not significant, but canopy photosynthetic ability of super-high cultivation was significantly higher than normal high-yield cultivation. From the silking stage to 40 days, SOD and POD activities were higher than the normal cultivation and MDA content lower than the normal cultivation.【Conclusion】The super-high yield spring maize has higher LAI and population photosynthetic potential, smaller leaf angle and higher leaf direction value, and canopy structure is reasonable. The super-high yield spring maize has stronger SOD and POD activities, lower the MDA content, higher net photosynthetic rate and stronger photosynthetic potential. So under the reasonable cultivation technique condition, collaborative gain can be obtained from super-high-yield spring maize community structure and individual function.
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DOI:10.3864/j.issn.0578-1752.2011.21.005URL [本文引用: 1]
【Objective】 Canopy structure and canopy functional characteristics of super-high yield spring maize populations were studied to reveal the physiological mechanism of formation of super-high yield, which provided a theoretical basis for cultivation of super-high yield spring maize.【Method】The Jinshan 27 was grown under super-high-yield cultivation (SHY) and normal high-yield cultivation (CK) condition in 2009 and 2010 to assess the indexes of canopy structure and physiological characteristics of super-high yield maize.【Result】Compared with normal high-yield cultivation, the super-high yield spring maize had higher leaf area index (LAI), and three-ear leaves was more obvious after silking stage. Leaf angle of different leaf locations was lower and the leaf direction value was higher than normal high-yield cultivation, and particularly in the three-ear. With the process of the growing period, the difference of photosynthetic potential between the super-high-yield cultivation and the normal high-yield cultivation increased. In the silking stage and milking stage, the difference of the net photosynthetic rate of two cultivation modes was not significant, but canopy photosynthetic ability of super-high cultivation was significantly higher than normal high-yield cultivation. From the silking stage to 40 days, SOD and POD activities were higher than the normal cultivation and MDA content lower than the normal cultivation.【Conclusion】The super-high yield spring maize has higher LAI and population photosynthetic potential, smaller leaf angle and higher leaf direction value, and canopy structure is reasonable. The super-high yield spring maize has stronger SOD and POD activities, lower the MDA content, higher net photosynthetic rate and stronger photosynthetic potential. So under the reasonable cultivation technique condition, collaborative gain can be obtained from super-high-yield spring maize community structure and individual function.
URL [本文引用: 2]
【Objective】Rice is one of the most important food crops in China. The realization of its super-high-yielding has a great significance for food security of the country. This study investigated the growth and development characteristics of the super-high-yielding (grain yield >11 t·ha-1) of rice.【Method】Four mid-season japonica rice cultivars (including lines), Lianjiajing 2, Huajing 5, 0026 and 9823, were grown in a paddy field. Growth analysis was performed during the growth period, and yield and yield components were determined at maturity.【Result】Super-high-yielding rice had more sipkelets per panicle and higher filled-grain percentage than the high-yielding rice (CK, grain yield 8.98～9.16 t·ha-1). There was no significant difference in 1000-grain weight between the super-high-yielding and the CK. Super-high-yield rice exhibited fewer tillers at the early growth stage (from transplanting to jointing), while a higher ratio of productive tillers to total tillers, as compared with the CK. The leaf area index, photosynthetic potential and dry matter accumulation of the super-high-yielding rice were lower than those of the CK at the early growth stage, and their differences were not significant between the two rice types at heading, and were greater for the former than the later after heading. The root-shoot ratio at each growth stage, root bleedings from heading to maturity, grain-leaf ratio, translocation percentage of the matter from stems and sheaths and harvest index of super-high-yielding rice were greater than those of CK. 【Conclusion】 The indexes for the growth and development of super-high-yielding mid-season rice population were suggested, i. e., total spikelets > 4.5 × 104·m-2, filled-grain percentage > 90%, 1000-grain weight > 26 g; ratio of productive tillers > 80%, leaf area index at heading 7.5-8.0, photosynthetic potential during whole growth period > 5×106 m2·d·ha-1, total dry matter weight at maturity >22 t·ha-1, harvest index > 0.51; grain-leaf ratio (No of spikelets per cm2 leaf area) > 0.58; root-shoot ratio at heading stage >0.25 and the amount of root exudates > 5 g·m-2·h-1. The regulation approaches and key cultivation techniques for raising the super-high-yielding population were discussed.
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URL [本文引用: 2]
【Objective】Rice is one of the most important food crops in China. The realization of its super-high-yielding has a great significance for food security of the country. This study investigated the growth and development characteristics of the super-high-yielding (grain yield >11 t·ha-1) of rice.【Method】Four mid-season japonica rice cultivars (including lines), Lianjiajing 2, Huajing 5, 0026 and 9823, were grown in a paddy field. Growth analysis was performed during the growth period, and yield and yield components were determined at maturity.【Result】Super-high-yielding rice had more sipkelets per panicle and higher filled-grain percentage than the high-yielding rice (CK, grain yield 8.98～9.16 t·ha-1). There was no significant difference in 1000-grain weight between the super-high-yielding and the CK. Super-high-yield rice exhibited fewer tillers at the early growth stage (from transplanting to jointing), while a higher ratio of productive tillers to total tillers, as compared with the CK. The leaf area index, photosynthetic potential and dry matter accumulation of the super-high-yielding rice were lower than those of the CK at the early growth stage, and their differences were not significant between the two rice types at heading, and were greater for the former than the later after heading. The root-shoot ratio at each growth stage, root bleedings from heading to maturity, grain-leaf ratio, translocation percentage of the matter from stems and sheaths and harvest index of super-high-yielding rice were greater than those of CK. 【Conclusion】 The indexes for the growth and development of super-high-yielding mid-season rice population were suggested, i. e., total spikelets > 4.5 × 104·m-2, filled-grain percentage > 90%, 1000-grain weight > 26 g; ratio of productive tillers > 80%, leaf area index at heading 7.5-8.0, photosynthetic potential during whole growth period > 5×106 m2·d·ha-1, total dry matter weight at maturity >22 t·ha-1, harvest index > 0.51; grain-leaf ratio (No of spikelets per cm2 leaf area) > 0.58; root-shoot ratio at heading stage >0.25 and the amount of root exudates > 5 g·m-2·h-1. The regulation approaches and key cultivation techniques for raising the super-high-yielding population were discussed.
DOI:10.7606/j.issn.1009-1041.2010.06.018URL [本文引用: 1]
Super high yield wheat cultivars Luomai 21 and Wenmai 18 were planted in the high yield wheat field with favorable soil, fertilizer and water conditions were used to study grain yield capacity, photosynthetic characteristics and carbon and nitrogen metabolism at late growth stages of wheat. The results showed that: the yield of super high yield wheat cultivars Luomai 21 and Zhoumai 18 increased more significant than that of Wenmai 6(CK) by 13.02% and 9.92%,respectively. The difference in number of ears of super high yield wheat cultivars per hectare was not significant with CK,kernels per ear were 38, the thousand grain weight was more than 49 g,which were different significantly with CK. Pn, photosynthetic leaf area index and PSⅡmaximum photochemical efficiency (Fv/Fm) of super high yield wheat cultivars were higher than those of CK at late growth period, and their growth periods were longer and chlorophyll contents were higher. At the same time, soluble sugar content and soluble protein content in flag leaves of super high yield wheat were higher and decreased more slowly than CK; showing their higher ability to use light and longer duration of photosynthetic function. That was key physiological reason for grain yield enhancement during wheat cultivars improvement.
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DOI:10.7606/j.issn.1009-1041.2010.06.018URL [本文引用: 1]
Super high yield wheat cultivars Luomai 21 and Wenmai 18 were planted in the high yield wheat field with favorable soil, fertilizer and water conditions were used to study grain yield capacity, photosynthetic characteristics and carbon and nitrogen metabolism at late growth stages of wheat. The results showed that: the yield of super high yield wheat cultivars Luomai 21 and Zhoumai 18 increased more significant than that of Wenmai 6(CK) by 13.02% and 9.92%,respectively. The difference in number of ears of super high yield wheat cultivars per hectare was not significant with CK,kernels per ear were 38, the thousand grain weight was more than 49 g,which were different significantly with CK. Pn, photosynthetic leaf area index and PSⅡmaximum photochemical efficiency (Fv/Fm) of super high yield wheat cultivars were higher than those of CK at late growth period, and their growth periods were longer and chlorophyll contents were higher. At the same time, soluble sugar content and soluble protein content in flag leaves of super high yield wheat were higher and decreased more slowly than CK; showing their higher ability to use light and longer duration of photosynthetic function. That was key physiological reason for grain yield enhancement during wheat cultivars improvement.
URL [本文引用: 1]
The objective of study was to determine the changing trends of plant height, leaf area index, dry matter accumulation, crop growth rate and the correlation between those colony parameters and seed yield. The results indicated that the yield reached to the highest, 5695.2kg/hm2, with the planting density of 288700/hm2; the biggest leaf area index was gained after 84 days of emergence while the leaf area duration was 2602269g.m2/hm2; the net photosynthetic rate was 5.19 g/m2.d after the 105 days of emergence, which is the biggest in the whole growth period. The results also showed that those main colony physiological parameters of “Xin Dadou 1” in the early growth period were superior to that in the later. There were significant correlativities between most of parameters in the periods of beginning bloom and full bloom.
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URL [本文引用: 1]
The objective of study was to determine the changing trends of plant height, leaf area index, dry matter accumulation, crop growth rate and the correlation between those colony parameters and seed yield. The results indicated that the yield reached to the highest, 5695.2kg/hm2, with the planting density of 288700/hm2; the biggest leaf area index was gained after 84 days of emergence while the leaf area duration was 2602269g.m2/hm2; the net photosynthetic rate was 5.19 g/m2.d after the 105 days of emergence, which is the biggest in the whole growth period. The results also showed that those main colony physiological parameters of “Xin Dadou 1” in the early growth period were superior to that in the later. There were significant correlativities between most of parameters in the periods of beginning bloom and full bloom.
DOI:10.3864/j.issn.0578-1752.2013.12.004URL [本文引用: 1]
【Objective】Canopy structure and characteristics of high yield and high nitrogen efficiency summer maize were studied to discuss the physiological mechanism of achieving high yield and high nitrogen efficiency, which will provide a theoretical basis for high yield and high nitrogen efficiency cultivation of summer maize.【Method】Integrated management experiment (MT) and nitrogen treatments (NT) were designed to achieve high yield and high nitrogen efficiency and then reveal canopy structure and photosynthetic characteristics of summer maize by optimizing integrated agricultural management, such as sowing date, sowing methods, planting density, fertilizers applied date and levels, and so on.【Result】In NT, grain yield and light transmission of ear layer and ground floor achieved maximum at 184.5 kgN•hm-2 while the leaves area index (LAI) high value duration was long. Beyond this level, light transmission and net photosynthetic rate of ear layer decreased actually. In MT, the leaf area index (LAI) of further optimized combination of cropping systems and fertilizer treatment (Opt-2) always remained above 4.4 from twelve-leaf stage (V12) to six weeks after tasseling stage (6WAT) and its decrease speed was low in latter growing period; its light transmission of ear layer and ground floor, the internode length above ear, the uniformity of plant character was high, achieving grain yield of 10.91 t?hm-2 and nitrogen use efficiency of 54.97 kg?kg-1.【Conclusion】Grain yield did not increase as nitrogen fertilizer application increasing without limit and light transmission decreased when nitrogen fertilization was large. With an integration of agronomic measures and fertilizers management, the LAI high value duration of Opt-2 was longer. light transmittance of ear layer, the uniformity of plant character, the net photosynthetic rate, grain yield and nitrogen use efficiency were high. Consequently, Opt-2 achieved both higher yields and higher nitrogen use efficiency.
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DOI:10.3864/j.issn.0578-1752.2013.12.004URL [本文引用: 1]
【Objective】Canopy structure and characteristics of high yield and high nitrogen efficiency summer maize were studied to discuss the physiological mechanism of achieving high yield and high nitrogen efficiency, which will provide a theoretical basis for high yield and high nitrogen efficiency cultivation of summer maize.【Method】Integrated management experiment (MT) and nitrogen treatments (NT) were designed to achieve high yield and high nitrogen efficiency and then reveal canopy structure and photosynthetic characteristics of summer maize by optimizing integrated agricultural management, such as sowing date, sowing methods, planting density, fertilizers applied date and levels, and so on.【Result】In NT, grain yield and light transmission of ear layer and ground floor achieved maximum at 184.5 kgN•hm-2 while the leaves area index (LAI) high value duration was long. Beyond this level, light transmission and net photosynthetic rate of ear layer decreased actually. In MT, the leaf area index (LAI) of further optimized combination of cropping systems and fertilizer treatment (Opt-2) always remained above 4.4 from twelve-leaf stage (V12) to six weeks after tasseling stage (6WAT) and its decrease speed was low in latter growing period; its light transmission of ear layer and ground floor, the internode length above ear, the uniformity of plant character was high, achieving grain yield of 10.91 t?hm-2 and nitrogen use efficiency of 54.97 kg?kg-1.【Conclusion】Grain yield did not increase as nitrogen fertilizer application increasing without limit and light transmission decreased when nitrogen fertilization was large. With an integration of agronomic measures and fertilizers management, the LAI high value duration of Opt-2 was longer. light transmittance of ear layer, the uniformity of plant character, the net photosynthetic rate, grain yield and nitrogen use efficiency were high. Consequently, Opt-2 achieved both higher yields and higher nitrogen use efficiency.
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DOI:10.5846/stxb201203120329URL [本文引用: 1]
选用平展大穗型品种鲁单981(Ludan981,LD981)和紧凑中穗型品种鲁单818(Ludan818,LD818),在两种种植密度(60000和90000株/hm2)和两种种植方式(单株和双株)下,研究了密植及种植方式对夏玉米冠层和根系结构与功能以及子粒产量等的影响。研究发现,随种植密度增加,冠层垂直分布呈现干重比例权重上移的趋势,根系则呈现下移的趋势。密植条件下, LD981冠层对生长空间更为敏感,其根系对生长空间的竞争强于冠层,其群体产量限制因素是子粒库容;LD818根系对生长空间更为敏感,冠层对生长空间的竞争强于根系,其群体产量限制因素是单位面积穗数。60000株/hm2下,LD981的群体结构质量和功能较优,双株种植可缓解其冠层竞争,根、冠协调,表现增产;在90000株/hm2下,LD818的群体结构质量和功能较优,双株种植可缓解其根系竞争,部分改善冠层群体结构质量和功能,根、冠协调,表现增产。
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DOI:10.5846/stxb201203120329URL [本文引用: 1]
选用平展大穗型品种鲁单981(Ludan981,LD981)和紧凑中穗型品种鲁单818(Ludan818,LD818),在两种种植密度(60000和90000株/hm2)和两种种植方式(单株和双株)下,研究了密植及种植方式对夏玉米冠层和根系结构与功能以及子粒产量等的影响。研究发现,随种植密度增加,冠层垂直分布呈现干重比例权重上移的趋势,根系则呈现下移的趋势。密植条件下, LD981冠层对生长空间更为敏感,其根系对生长空间的竞争强于冠层,其群体产量限制因素是子粒库容;LD818根系对生长空间更为敏感,冠层对生长空间的竞争强于根系,其群体产量限制因素是单位面积穗数。60000株/hm2下,LD981的群体结构质量和功能较优,双株种植可缓解其冠层竞争,根、冠协调,表现增产;在90000株/hm2下,LD818的群体结构质量和功能较优,双株种植可缓解其根系竞争,部分改善冠层群体结构质量和功能,根、冠协调,表现增产。
DOI:10.3724/SP.J.1006.2008.00447URL [本文引用: 1]
Canopy structure has strong effects on photosynthesis and grain yield in maize (Zea mays L.). Planting density is one of the most important factors that can regulate canopy structure. Many researches have shown that leaf area index (LAI) and leaf area duration (LAD) increase accordantly with the proper increase of planting density, but the percent transmission decreases sharply under excessive high density, resulting in uneven light distribution within canopy and photosynthesis reduction. We need to know which proper planting densities for cultivars lead to little influence on photosynthesis and higher grain yield in summer maize. However, so far few reports on this topic have been found and no quantitative criteria can be used in evaluating canopy structure of different maize cultivars. Therefore, we conducted an experiment with three cultivars and three planting densities in the field having medium soil fertility and application of 180 kg N ha-1 in Wuqiao Experimental Station (37°41′02″N，116°37′23″E) of China Agricultural University in 2006 to establish such quantitative criteria for high yielding cultivars in North China Plain. The split plot design was employed with main plot of plant density (low, medium, and high respectively), sub-plot of cultivar (CF008, Zhengdan 958, and Jinhai 5 respectively), and three replicates in each sup-plot. According to plant type, the densities of three cultivars were 9.75×104 (low), 11.25×104 (medium), and 12.45×104 (high) plants ha-1 for CF008; 8.25×104 (low), 9.75×104 (medium), and 11.25×104 (high) plants ha-1 for Zhengdan 958; and 6.75×104 (low), 8.25×104 (medium), and 9.75×104 (high) plants ha-1 for Jinhai 5. The high-yielding canopy structure and photosynthesis were obtained under both low and medium densities of the three cultivars. Percent transmission, leaf angle, and stem diameter decreased with the increase of plant density. The chlorophyll relative content (SPAD) and the rate of net photosynthesis rate (Pn) were the smallest under high density because of the uneven light distribution within canopy. For CF008, SPAD value of ear leaf and the third leaf under ear decreased sharply in later growth stages. LAD and LAI values before mid-filling stage were greater under medium or high densities, while different tendency occurred in the maturity stages. Moreover, the proportion of after-silking LAD was greater under low or medium densities, showing that canopy structure was unsuitable under high density due to early senescence. For Zhengdan 958 and Jinhai 5, LAD after silking was greater than that before silking, which was benefit for high grain yield. Our results confirmed that proper planting density can establish high-yielding canopy structure and improve population photosynthesis and yield in maize. We also obtained a series quantitative criteria for high-yielding canopy structure based on the data from Wuqiao area: percent transmission of 13.4%–19.45% in silking stage and 16.19%–21.48% in mid-filling stage under low or medium densities; LAI of 5.59–6.75 in silking stage and 2.24–3.68 in maturity stage, especially highen in middle and upper leaf layers in maturity stage under low or medium densities; Pn of 33.6–43.8 μmol CO2 m-2 s-1 in middle and upper layer leaves in silking stage under low or medium densities; higher LAD after silking under low or medium densities, with 172.01–235.91 m2 d m-2 under medium density.
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DOI:10.3724/SP.J.1006.2008.00447URL [本文引用: 1]
Canopy structure has strong effects on photosynthesis and grain yield in maize (Zea mays L.). Planting density is one of the most important factors that can regulate canopy structure. Many researches have shown that leaf area index (LAI) and leaf area duration (LAD) increase accordantly with the proper increase of planting density, but the percent transmission decreases sharply under excessive high density, resulting in uneven light distribution within canopy and photosynthesis reduction. We need to know which proper planting densities for cultivars lead to little influence on photosynthesis and higher grain yield in summer maize. However, so far few reports on this topic have been found and no quantitative criteria can be used in evaluating canopy structure of different maize cultivars. Therefore, we conducted an experiment with three cultivars and three planting densities in the field having medium soil fertility and application of 180 kg N ha-1 in Wuqiao Experimental Station (37°41′02″N，116°37′23″E) of China Agricultural University in 2006 to establish such quantitative criteria for high yielding cultivars in North China Plain. The split plot design was employed with main plot of plant density (low, medium, and high respectively), sub-plot of cultivar (CF008, Zhengdan 958, and Jinhai 5 respectively), and three replicates in each sup-plot. According to plant type, the densities of three cultivars were 9.75×104 (low), 11.25×104 (medium), and 12.45×104 (high) plants ha-1 for CF008; 8.25×104 (low), 9.75×104 (medium), and 11.25×104 (high) plants ha-1 for Zhengdan 958; and 6.75×104 (low), 8.25×104 (medium), and 9.75×104 (high) plants ha-1 for Jinhai 5. The high-yielding canopy structure and photosynthesis were obtained under both low and medium densities of the three cultivars. Percent transmission, leaf angle, and stem diameter decreased with the increase of plant density. The chlorophyll relative content (SPAD) and the rate of net photosynthesis rate (Pn) were the smallest under high density because of the uneven light distribution within canopy. For CF008, SPAD value of ear leaf and the third leaf under ear decreased sharply in later growth stages. LAD and LAI values before mid-filling stage were greater under medium or high densities, while different tendency occurred in the maturity stages. Moreover, the proportion of after-silking LAD was greater under low or medium densities, showing that canopy structure was unsuitable under high density due to early senescence. For Zhengdan 958 and Jinhai 5, LAD after silking was greater than that before silking, which was benefit for high grain yield. Our results confirmed that proper planting density can establish high-yielding canopy structure and improve population photosynthesis and yield in maize. We also obtained a series quantitative criteria for high-yielding canopy structure based on the data from Wuqiao area: percent transmission of 13.4%–19.45% in silking stage and 16.19%–21.48% in mid-filling stage under low or medium densities; LAI of 5.59–6.75 in silking stage and 2.24–3.68 in maturity stage, especially highen in middle and upper leaf layers in maturity stage under low or medium densities; Pn of 33.6–43.8 μmol CO2 m-2 s-1 in middle and upper layer leaves in silking stage under low or medium densities; higher LAD after silking under low or medium densities, with 172.01–235.91 m2 d m-2 under medium density.
URLPMID:11962320 [本文引用: 1]
Taken maize in two plant types of compact-type and flat-type as research object, the relationships between density-tolerance and light distribution in population, indices of productivity(LAI, NAR, and CGR), and population sink-source were studied synthetically by means of crop growth analysis method. The results showed that light distribution in population was the chief index to measure density-tolerance of different maize varieties. The kinetic rules of LAI, NAR, and CGR were the basic feature reflecting density-tolerance. The correspondent relationship in population sink-source was a comprehensive index to appraise density-tolerance of different maize varieties.
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URLPMID:11962320 [本文引用: 1]
Taken maize in two plant types of compact-type and flat-type as research object, the relationships between density-tolerance and light distribution in population, indices of productivity(LAI, NAR, and CGR), and population sink-source were studied synthetically by means of crop growth analysis method. The results showed that light distribution in population was the chief index to measure density-tolerance of different maize varieties. The kinetic rules of LAI, NAR, and CGR were the basic feature reflecting density-tolerance. The correspondent relationship in population sink-source was a comprehensive index to appraise density-tolerance of different maize varieties.
URL [本文引用: 1]
Tomato plants were dealed with 35℃ sub-high temperature in greenhouse from the first bud of tomato effloresced to 30 days after florescence. The results showed that under the condition of sub2high temperature, the net photosynthetic rate, stomatal limitation of photosynthesis and the content of chlorophyll of tomato leaves decreased. Ultrastructure of chlorop last was changed. The numbers of stoma increased obviously, and the opening degree of stoma was much larger than the control at 25℃. The envelope of chloroplast was partially injured, the number of grana decreased, and the thylakoids of grana was loose. The number of oil body increased while the starch grain decreased first then increased. Effects of 35℃ sub-high temperature on the photosynthesis of tomato leaveswere independent of stoma factors.
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URL [本文引用: 1]
Tomato plants were dealed with 35℃ sub-high temperature in greenhouse from the first bud of tomato effloresced to 30 days after florescence. The results showed that under the condition of sub2high temperature, the net photosynthetic rate, stomatal limitation of photosynthesis and the content of chlorophyll of tomato leaves decreased. Ultrastructure of chlorop last was changed. The numbers of stoma increased obviously, and the opening degree of stoma was much larger than the control at 25℃. The envelope of chloroplast was partially injured, the number of grana decreased, and the thylakoids of grana was loose. The number of oil body increased while the starch grain decreased first then increased. Effects of 35℃ sub-high temperature on the photosynthesis of tomato leaveswere independent of stoma factors.
DOI:10.1007/s11099-006-0011-zURL [本文引用: 1]
The contents of chlorophyll (Chl) and carotenoids (Car) per fresh mass were lower in shade needles than in sun needles. Ribulose-1,5-bisphosphate carboxylase (RuBPC) activity and contents of soluble proteins were also significantly lower in shade needles. In isolated thylakoids, a marked lower rate of whole chain and photosystem (PS) 2 activities were observed in shade needles. Smaller lower rate of PS1 activity was also observed in shade needles. The artificial exogenous electron donors, diphenyl carbazide (DPC) and NH2OH, significantly restored the loss of PS2 activity in shade needles. Similar results were obtained when Fv/Fm was evaluated by Chl fluorescence measurements. The marked lower rate of PS2 activity in shade needles was due to the lower contents of 47, 33, 28–25, 23, and 17 kDa polypeptides. This conclusion was confirmed by immunological studies showing that the content of the 33 kDa protein of the watersplitting complex was diminished significantly in shade needles.
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