摘要
摘要:本试验以‘中杂9号’番茄为试材，采用砂培法，设置对照（0.66 mmol·L^-1）、轻度缺磷（0.44 mmol·L^-1）、重度缺磷（0.22 mmol·L^-1）和无磷（0 mmol·L^-1）4个磷浓度，研究了柠檬酸（7.5 mmol·L^-1）浸种对低磷胁迫下番茄种子萌发、幼苗生长及生理特性的影响，旨在阐明柠檬酸浸种缓解番茄低磷胁迫的生理机制。结果表明：与蒸馏水浸种相比，不同浓度柠檬酸浸种引发显著提高了番茄发芽率、发芽势、发芽指数，最佳浓度为7.5 mmol·L^-1。与对照相比，低磷胁迫下番茄幼苗生长受到严重抑制，丙二醛（MDA）、活性氧（$ $\text{O}_2^{\bar \cdot }$$、H₂O₂）含量显著升高，超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性显著减低；可溶性蛋白、可溶性糖及甜菜碱含量显著升高，渗透势降低；而柠檬酸浸种引发明显促进了番茄幼苗的生长，增加了生物量的积累；提高了番茄中抗氧化酶活性，降低了MDA和活性氧的积累，减轻了番茄幼苗的氧化胁迫；显著提高了有机酸、可溶性糖等的含量，缓解了渗透势的下降；显著提高了番茄幼苗中的磷含量，缓解了植株的低磷胁迫症状。综上所述，柠檬酸浸种引发通过缓解低磷胁迫对番茄造成的氧化损伤，提高磷素吸收，维持正常生长代谢，从而增强番茄幼苗对低磷胁迫的抵抗能力。
关键词:番茄/
低磷胁迫/
种子引发/
柠檬酸/
抗氧化系统/
渗透调节
Abstract:To explore the effects of seed priming with citric acid on tomato seed germination, seedling growth and physiological characteristics under low phosphorus stress, 'Zhongza 9' was cultured in sand at four phosphorus concentrations: control (0.66 mmol·L^-1), mild phosphorus deficiency (0.44 mmol·L^-1), severe phosphorus deficiency (0.22 mmol·L^-1), and non-phosphorus (0 mmol·L^-1). The tomato seeds were soaked in citric acid (7.5 mmol·L^-1), and the seed germination, seedlings growth and physiological characteristics were examined. This experiment aimed to clarify the physiological mechanisms of citric acid seed priming in alleviating low phosphorus stress in tomatoes. The results showed that, compared with seed soaking in distilled water, the different concentrations of citric acid seed soaking significantly increased the germination rate, germination potential, and germination index; the optimal concentration was 7.5 mmol·L^-1. Compared with the control, tomato seedling growth under low phosphorus stress was severely inhibited; the malondialdehyde (MDA) and reactive oxygen species ($ $\text{O}_2^{\bar \cdot }$$, H₂O₂) contents significantly increased; and the superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities significantly decreased. The soluble protein, soluble sugar, and betaine contents significantly increased, and the osmotic potential was low. The seed priming with citric acid significantly promoted tomato seedling growth, increased biomass accumulation, increased the activities of antioxidant enzymes, reduced the accumulation of MDA and reactive oxygen species, and reduced the oxidative stress in tomato seedlings. It also significantly improved the organic acid and soluble sugar contents, alleviated osmotic potential decline, increased the phosphorus content, and lessened the symptoms of low phosphorus stress. In summary, priming tomato seeds with citric acid alleviated the oxidative damage caused by low phosphorus, improved the absorption efficiency of phosphorus, maintained normal growth and metabolism, and enhanced the resistance of tomato seedlings to low phosphorus stress.
Key words:Tomato/
Low phosphorus stress/
Seed priming/
Citric acid/
Antioxidant system/
Osmotic regulation



PDF全文下载地址:

http://www.ecoagri.ac.cn/article/exportPdf?id=27e850e8-1bc1-447e-871a-65f26af2b8d2