Comparison of Heat Tolerance of Seven Varieties of Tomato Seedlings under Short-Term Heat Stress

Ye Minghui; Li Yanan; Bi Hongyu; Cui Yingjiao; Wang Deying; Wu Bingjie

doi:10.14083/j.issn.1001-4942.2025.07.012

Abstract：Tomato as a temperature-loving vegetable,high-temperature stress can cause serious damage to its growth and development,leading to a significant reduction in yield.Therefore,screening out heat-tolerant to-mato varieties as heat-tolerant germplasm resources or for direct use in production highlights important functions and significance.In this experiment,seven tomato varieties of Red Bull Heart(T1),Lotus 514(T2),74-33(T3),75-90(T4),Powerful Mishou(T5),Datong Harvest Red(T6)and Wild Tomato(T7)were used as materials,and the effects of high temperature stress at 40℃ on activities of antioxidant enzymes of peroxidase(POD)and catalase(CAT),contents of malondialdehyde(MDA)and relative chlorophyll(SPAD)of tomato seedling leaves,maximum photochemical efficiency(Fv/Fm)and net photosynthesis rate(Pn)were studied u-sing 25℃ as the control condition.The heat tolerance of the seven varieties were comprehensively evaluated u-sing the method of comprehensive membership function,and they were clustered by cluster analysis.The results showed that compared with the control,the SPAD value and Pn of each tomato variety significantly decreased,MDA content increased,Fv/Fm decreased significantly except for T3 variety,POD activity increased except for T2 and T5 varieties,and CAT activity increased except for T2,T5 and T7 varieties after subjected to high-tem-perature stress of 40 ℃.The ranking of the heat tolerance of the seven tomato varieties obtained by using the comprehensive membership function method as 74-33＞Powerful Mishou＞Datong Harvest Red＞Wild Tomato＞75-90＞Red Bull Heart＞Lotus 514.The tomato varieties were divided into three categories by cluster analysis,among which,74-33 was strong heat-tolerant variety,75-90,Powerful Mishou,Datong Harvest Red and Wild Tomato were medium heat-toleant varieties,and Red Bull Heart and Lotus 514 were heat-sensitive varieties.These con-clusions could provide a reference for screening,innovation and utilization of heat-tolerant germplasm resources of tomato,as well as the exploration of heat-resistant genes.