水杨酸对盐胁迫下辣椒种子萌发及幼苗生长的影响

Effects of Salicylic Acid on Seed Germination and Seedling Growth of Pepper Under Salt Stress

该试验对NaCl胁迫下生长的辣椒幼苗进行水杨酸(SA)处理,分别采用浸种法和水培法在种子萌发期和幼苗期进行研究,以期研究外源SA对盐胁迫下作物生长的缓解作用,降低盐胁迫对作物的伤害,提高中、轻度盐碱地的利用率。结果表明:盐胁迫会抑制辣椒种子的萌发和幼苗生长,当SA浓度为0.15 mmol·L^-1时,种子的发芽势、发芽率等最高,缓解盐胁迫的效果最佳;利用外源水杨酸对盐胁迫下的辣椒苗进行生长调控,叶片的净光合速率(Pn)、气孔导度(Gs)显著降低,细胞间隙CO2浓度(Ci)持续升高,表明SA可以缓解盐胁迫对植物的抑制作用,提高叶片光合作用的效率,同时与NaCl处理相比,叶绿素含量在第3、6、9天分别增加51%、34%、40%,这表明SA可以缓解盐胁迫对辣椒幼苗的生长抑制,促进叶片叶绿素的合成,保护其光合作用,维持植物的正常生长。

To investigate the role of exogenous salicylic acid(SA) in alleviating the damage of salt stress on crops and improving the utilization of medium and light saline-alkali soils,the pepper seedlings under NaCl stress were treated with SA,and the seed germination and seedling stages were studied by soaking and hydroponic methods respectively in this study.The results showed that salt stress could inhibit the germination and seedling growth of pepper.When the concentration of SA was 0.15 mmol·L^-1,the germination potential and germination percentage of the seeds were the highest,and the effect of alleviating salt stress damage was the best.The net photosynthetic rate(Pn) and the stomatal conductance(Gs) decreased significantly and the intercellular CO2 concentration(Ci) of pepper seedlings continued to increase under salt stress treated with SA,indicated SA could alleviate the inhibition of on plants under salt stress and improve the photosynthesis efficiency of leaves.Meanwhile,compared with NaCl treatment,the chlorophyll content of SA treatment increased by 51%,34% and 40% for 3,6 and 9 days,respectively,showed that SA could alleviate pepper seedlings damage under salt stress,promote the synthesis of chlorophyll,protect photosynthesis system and maintain the normal growth of plants.