摘要
【目的】探讨叶面预喷施不同浓度水杨酸(SA)对西瓜幼苗高温胁迫伤害的缓解效应及其生理机制,为SA在西瓜栽培和生产中合理应用提供理论基础。【方法】以温室内盆栽‘K53’西瓜幼苗为试验材料,先叶面喷施不同浓度(0,0.5,1.0,1.5,2.0 mmol/L)SA,后经昼夜42℃胁迫36 h,观测西瓜幼苗生长特性、解剖结构及生理生化指标,并用隶属函数法综合评价各处理的缓解效应。【结果】在高温胁迫后,西瓜幼苗叶片萎蔫严重,根长生长受到抑制,叶片变薄、叶肉细胞结构受损。施加SA后叶片变厚,光合色素含量、光合气体交换参数、抗氧化酶(POD、SOD、CAT)活性及渗透调节物质(脯氨酸、可溶性糖、可溶性蛋白)含量显著升高,MDA含量和相对电导率显著下降。与高温胁迫处理相比,1.0 mmol/L SA处理叶片的MDA含量和相对电导率分别显著降低33.70%、58.58%,叶绿素a含量、叶绿素b含量、净光合速率及SOD、CAT活性分别显著升高22.71%、21.63%、98.34%、23.98%和19.71%。【结论】叶面预喷施不同浓度的SA均能有效缓解西瓜幼苗高温胁迫伤害,并以1.0 mmol/L SA处理效果最佳。
[Objective]This study aims to investigate the mitigation effect and physiological mechanism of salicylic acid(SA)on high temperature stress injury of watermelon seedlings,and to provide a theoretical basis for the application of SA in watermelon cultivation.[Methods]Potted‘K53’watermelon seedlings in greenhouse were used as experimental materials.After spraying different concentrations(0,0.5,1.0,1.5,and 2.0 mmol/L)of SA on the leaves,the seedlings were stressed at 42℃for 36 h.The growth characteristics,anatomical structure,physiological and biochemical indexes of watermelon seedlings were observed,and the mitigation effects of each treatment were comprehensively evaluated by membership function method.[Results]After high temperature stress,the leaves of watermelon seedlings were wilted seriously,the growth of root length was inhibited,the leaves became thinner,and the mesophyll cell structure was damaged.After SA application,the leaves became thicker,photosynthetic pigment content,photosynthetic gas exchange parameters,antioxidant enzyme(POD,SOD,CAT)activity and osmotic ad-justment substances(proline,soluble sugar,soluble protein)content were increased significantly,while MDA content and relative conductivity were decreased significantly.Compared with the high temperature stress group,the MDA content and relative conductivity of leaves under 1.0 mmol/L SA treatment were reduced by 33.70%and 58.58%,while the contents of chlorophyll a and chlorophyll b,net photosynthetic rate,and the activities of SOD and CAT were increased by 22.71%,21.63%,98.34%,23.98%and 19.71%,respectively.[Conclusion]Pre-spraying SA could alleviate the damage of watermelon seedlings under high temperature stress,with 1.0 mmol/L SA had the best effect.
作者
石文昕
郎俊凯
许玲兴
李爱
张卫华
张梁葛
SHI Wenxin;LANG Junkai;XU Lingxing;LI Ai;ZHANG Weihua;ZHANG Liangge(College of Horticulture and Landscape Architecture,Tianjin Agricultural University,Tianjin 300392,China)
出处
《西北植物学报》
CAS
CSCD
北大核心
2024年第11期1692-1702,共11页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金项目(61971312)
国家级大学生创新创业训练计划项目(202410061038)。
关键词
西瓜
水杨酸
高温胁迫
叶片解剖结构
生理生化特性
Citrullus lanatus
salicylic acid
high temperature stress
leaf anatomical structure
physio-logical and biochemical characteristics
