Correlation analysis of salt damage parameters during watermelon ger-mination and seedling stages

XU Aolin; LIU Peng; SUN Jianlei; DONG Yumei; GAO Chao; GAO Yinan

doi:10.16861/j.cnki.zggc.2025.0424

Abstract：To investigate the correlation of salt tolerance between seed germination stage and seedling stage,and to deter-mine whether salt tolerance during germination can serve as an indicator for salt tolerance in the seedling stage,16 water-melon cultivars were used as experimental materials.Salt stress-related physiological and growth parameters—including germination potential,germination rate,salt injury index,total fresh masd,shoot fresh mass,chlorophyll content,malondi-aldehyde(MD A)content,and proline content—were measured at the germination and seedling stages.Principal compo-nent analysis,membership function analysis,and correlation analysis were employed to comprehensively evaluate salt tol-erance traits at both developmental stages.The results indicated that NaCl treatment significantly reduced total fresh mass and shoot fresh mass of seedlings,while increasing MDA and proline content.The comprehensive membership function value at the seedling stage ranged from 0.160 to 0.789.Based on key indicators such as salt injury index,fresh mass,shoot fresh mass,chlorophyll content,MDA content,and proline content,the 16 cultivars were classified into five salt tol-erance grades using cluster analysis.Similarly,at the germination stage,the comprehensive membership function values ranged from 0.043 to 0.830,and the cultivars were grouped into five salt tolerance classes.Correlation analysis between the average and comprehensive membership function values at the two stages—according to the five-grade classification system established at the germination stage—revealed Pearson correlation coefficients of 0.727 and 0.826,respectively,in-dicating a strong positive correlation between salt tolerance at the germination and seedling stages.These findings suggest that salt tolerance at the germination stage may be a reliable predictor of salt tolerance performance at the seedling stage in watermelon.The research results provide a theoretical basis for the early screening of watermelon salt-tolerant resource.