Abstract:
Water stress is a major cause of yield loss in peanut cultivation. Melatonin seed priming has been used to enhance stress tolerance in several crops, but not in peanut. We investigated the impact of seed priming with melatonin on the growth, development, and drought tolerance of two peanut cultivars, TUFRunner™ \'511\', a drought tolerant cultivar, and New Mexico Valencia A, a drought sensitive cultivar. Peanut seed priming tests using variable rates of melatonin (0-200 μM), indicated that 50 μM of melatonin resulted in more uniform seed germination and improved seedling growth in both cultivars under non stress conditions. Seed priming with melatonin also promoted vegetative growth, as evidenced by higher whole-plant transpiration, net CO2 assimilation, and root water uptake under both well-watered and water stress conditions in both cultivars. Higher antioxidant activity and protective osmolyte accumulation, lower reactive oxygen species accumulation and membrane damage were observed in primed compared with non-primed plants. Seed priming with melatonin induced a growth promoting effect that was more evident under well-watered conditions for TUFRunnner™ \'511\', whereas for New Mexico Valencia A, major differences in physiological responses were observed under water stress conditions. New Mexico Valencia A primed plants exhibited a more sensitized stress response, with faster down-regulation of photosynthesis and transpiration compared with non-primed plants. The results demonstrate that melatonin seed priming has significant potential to improve early establishment and promote growth of peanut under optimal conditions, while also improve stress tolerance during water stress.
摘要:
水分胁迫是花生栽培产量损失的主要原因。褪黑激素种子引发已用于增强几种作物的胁迫耐受性,但不是花生。我们研究了褪黑激素引发种子对生长的影响,发展,和两个花生品种的耐旱性,TUFRunner™\'511\',耐旱品种,和新墨西哥州瓦伦西亚A,对干旱敏感的品种。使用可变速率的褪黑激素(0-200μM)进行花生种子引发试验,表明在非胁迫条件下,50μM的褪黑激素可使两个品种的种子萌发更均匀,并改善幼苗生长。用褪黑激素引发种子也促进了营养生长,更高的整株植物蒸腾作用证明了这一点,净二氧化碳同化,在两个品种的水分充足和水分胁迫条件下,根系吸水。较高的抗氧化活性和保护性渗透物质积累,与未引发的植物相比,在引发的植物中观察到较低的活性氧积累和膜损伤。用褪黑激素引发种子诱导生长促进作用,在充分浇水的条件下,TUFRunnner™\'511\',而对于新墨西哥州瓦伦西亚A,在水分胁迫条件下观察到生理反应的主要差异。新墨西哥州瓦伦西亚一种引发的植物表现出更敏感的应激反应,与未引发的植物相比,光合作用和蒸腾作用的下调更快。结果表明,在最佳条件下,褪黑激素种子引发具有改善花生早期建立和促进生长的显着潜力。同时也提高了水分胁迫期间的胁迫耐受性。