摘要
摘要:为探讨磁化水灌溉处理在促进植物生长、提高植株重金属耐受性方面的作用机制，本研究采用随机区组试验设计，研究了镉胁迫（0 μmol·L^-1、50 μmol·L^-1、100 μmol·L^-1）下磁化水灌溉处理对1 a生欧美杨'I-107'光合特性、叶绿素荧光动力学参数及生长特性的影响。结果表明：1）镉胁迫会显著降低植株高生长和根茎叶干物质量；低浓度（50 μmol·L^-1）镉处理促进根系直径及体积增大（P < 0.05），高浓度（100 μmol·L^-1）则会抑制根系各形态参数；镉胁迫下欧美杨叶绿素b和类胡萝卜素含量分别降低12.50%、43.24%和19.27%、46.37%（P < 0.05），净光合速率（P_n）、蒸腾速率（T_r）、胞间二氧化碳（C_i）分别降低13.68%和33.68%、8.07%和27.81%、5.00%和14.99%（P < 0.05），同时，PSⅡ潜在活性（F_v/F_m）、最大光化学速率（F_v/F_o）、光合性能指数（PIabs）和量子产额（Φ_Eo）均有不同程度降低。2）磁化水灌溉提高镉胁迫植株高生长及根茎叶干物质量，增加植株根系长度及表面积；同时，叶绿素a、叶绿素b和类胡萝卜素含量在0 μmol·L^-1和100 μmol·L^-1镉胁迫下分别提高16.99%、40.20%，8.67%、39.10%和17.32%、50.52%（P < 0.05）；G_s、C_i及WUE显著升高，T_r则降低24.20%、23.33%、12.06%（P < 0.05）；另外，F_v/F_m、F_v/F_o、PIabs显著升高（P < 0.05）。综上所述，磁化水灌溉处理有助于提高镉胁迫下欧美杨幼苗光合色素含量，维持光合机构功能，增强光合碳同化速率，减轻镉胁迫对植株生长发育的抑制。
关键词:镉胁迫/
磁化水灌溉/
欧美杨I-107/
光合/
生长
Abstract:In order to investigate the effect of magnetized water irrigation on plant growth and tolerance to heavy metals, a randomized block experiment was designed to explore the photosynthetic characteristics, chlorophyll fluorescence kinetic parameters and growth characteristics of 1-year-old Populus×euramericanna 'Neva' under three cadmium concentrations (0 μmol·L^-1, 50 μmol·L^-1, 100 μmol·L^-1) of magnetized water solution. The results showed that:1) plant height, stem growth and dry matter weights of roots, leaves and stems significantly dropped under cadmium stress. While root diameter and volume were enhanced under low cadmium concentration (50 μmol·L^-1, P < 0.05), root morphology parameters were inhibited under high concentration (100 μmol·L^-1). Compared with 0 μmol·L^-1 cadmium treatment, chlorophyll b and carotenoid contents decreased respectively by 12.50% and 19.27% under 50 μmol·L^-1 cadmium treatment, and 43.24% and 46.37% under 100 μmol·L^-1 cadmium treatment (P < 0.05). Net photosynthetic rate (P_n), transpiration rate (T_r) and intercellular carbon dioxide concentration (C_i) respectively decreased by 13.68%, 8.07% and 5.00% under 50 μmol·L^-1 cadmium treatment, and by 33.68%, 27.81% and 14.99% (P < 0.05) under 100 μmol·L^-1 cadmium treatment. PSⅡ potential activity (F_v/F_m), maximum photo-chemical rate (F_v/F_o), photosynthetic performance index (PIabs) and quantum yield (Φ_Eo) also dropped to varying degrees. 2) Compared with non-magnetic water treatment, magnetic water treatment enhanced the growth of plants under cadmium stress in terms of height and stem, increased dry weight of roots and leaves and also root length and surface area of the plant. The contents of chlorophyll a increased by 16.99%, 6.55% and 4.02%, and carotenoid content increased by 17.32%, 19.38% and 50.52% (P < 0.05), respectively, under 0, 50 and 100 μmol·L^-1 cadmium treatments. While P_n, G_s, C_i and WUE increased, the differences were not significant. However, T_r reduced respectively by 24.20%, 23.33% and 12.06% (P < 0.05). In addition, F_v/F_m, F_v/F_o and Φ_Eo remained stable whereas PIabs increased respectively by 8.01%, 20.63% and 31.09% (P < 0.05). In summary, magnetic treatment of water increased the contents of photosynthetic pigments, maintained the function of photosynthetic apparatus, heightened the rate of photosynthetic carbon assimilation and subsequently relieved the inhibition of plant growth by cadmium stress.
Key words:Cadmium stress/
Magnetic treatment of water/
Populus×euramericanna 'Neva'/
Photosynthesis/
Plant growth



PDF全文下载地址:

http://www.ecoagri.ac.cn/article/exportPdf?id=b194f9c9-359f-4543-8556-fc6a6c311819