南方农业学报2024，Vol.55Issue(6)：1700-1712,13.DOI:10.3969/j.issn.2095-1191.2024.06.015
盐胁迫对嫁接西瓜幼苗盐离子分布和生理特性的影响
Effects of salt stress on salt ion distribution and physiological characteristics of grafted watermelon seedlings
摘要
Abstract
[Objective]This study aimed to investigate the effects of salt stress on salt ion distribution and physiologi-cal characteristics of grafted watermelon seedlings,providing a theoretical reference basis for regulating the growth of wa-termelon under salt stress and rationally developing and utilizing underground brackish water and salinized soil.[Method]The grafted watermelon seedlings were used as experimental materials,and the Hoagland nutrient solution with a nutrient solution salinity of 2.5 g/L as control(CK)was set as the base,supplemented with brackish water solutions with different salinities(3.0,3.5,4.0,and 4.5 g/L),to determine the fresh weight(FW),dry weight(DW),the relative content of chlorophyll(SPAD value),K+,Na+,Cl-accumulation and K+/Na+values in different tissues,as well as various physio-logical indicators[superoxide dismutase(SOD)and catalase(CAT)activities,proline(Pro),and malondialdehyde(MDA)contents)]of watermelon seedlings under the different treatments.Correlation analysis,principal component analysis(PCA),and salt stress threshold evaluation were conducted.[Result]With the increase of brackish water salini-ty,both FW and DW of watermelon seedlings showed a decreasing trend.FW decreased significantly by 33.38％and 38.08％compared with that of CK at salinities of 4.0 and 4.5 g/L respectively(P＜0.05,the same below).Cl-accumula-tion in the root system increased significantly by 348.43％to 492.52％at salinities of 3.0 and 4.5 g/L compared with the CK,while it peaked in stems and leaves under 4.5 g/L salinity.K+accumulation in different tissues decreased with increa-sing salinity,with significant reductions of 52.15％,52.16％and 54.61％in roots,stems and leaves respectively under 4.5 g/L salinity compared with CK.Na+accumulation in different tissues and whole plants of watermelon seedlings increased with increasing salinity of nutrient solution.K+/Na+values in roots,stems and leaves significantly decreased by 59.68％,61.63％and 52.70％under nutrient solution salinity of 4.5 g/L compared to CK respectively.The SPAD value of water-melon seedling leaves gradually decreased with increasing nutrient solution salinity,showing a linear correlation.SOD and CAT activities and Pro content in the leaves of watermelon seedlings showed quadratic,linearly decreasing and para-bolic relationships with the salinity respectively.The MDA content in both roots and leaves of watermelon seedlings in-creased with increasing brackish water salinity,with significant increases of 27.30％and 25.83％in roots,and 19.07％and 12.71％in leaves,compared with CK and 3.5 g/L salinity,respectively.Correlation analysis and PCA results showed a certain correlation between FW and ion accumulation in all tissues of watermelon seedlings.The cumulative contribution rate of the first principal component(PC1)and the second principal component(PC2)reached 67.8％.Salt stress thresh-old analysis and evaluation showed that the salinity thresholds under mild,moderate,and severe salt stress for water-melon seedlings were 2.80-3.91 g/L,3.91-5.32 g/L,and＞5.32 g/L respectively.[Conclusion]Under salt stress,Na+and Cl-accumulation in watermelon seedlings reduces K+uptake and destroys osmoregulatory substances and antioxidant en-zyme systems,causing membrane lipid oxidation and seedling biomass decrease.Leaf Pro content,stem Cl-accumula-tion,and leaf and root MDA contents can be used as comprehensive evaluation indicators for watermelon seedlings sub-jected to salt stress.关键词
盐胁迫/西瓜/盐分离子积累/生理特性Key words
salt stress/watermelon/salt ion accumulation/physiological characteristics分类
农业科技引用本文复制引用
李雪芳,谭军利,柳雪,王西娜,赵伟杰,孙晶晶,李小玉,马纪龙,何熙源,马佳乐..盐胁迫对嫁接西瓜幼苗盐离子分布和生理特性的影响[J].南方农业学报,2024,55(6):1700-1712,13.基金项目
National Natural Science Foundation of China(52369010) （52369010）
Ningxia Natural Science Foundation(2022AAC02013) （2022AAC02013）
Scientific Research Project for Higher Schools of Ningxia Department of Education(NYG2024012) （NYG2024012）
Innovation and Entrepreneurship Project for Undergraduates of Ningxia(S202210749082) 国家自然科学基金项目(52369010) （S202210749082）
宁夏自然科学基金项目(2022AAC02013) （2022AAC02013）
宁夏教育厅高等学校科学研究项目(NYG2024012) （NYG2024012）
宁夏大学生创新创业训练计划项目(S202210749082) （S202210749082）
