40份玉米自交系苗期耐盐碱胁迫综合评价体系构建及材料筛选OA

To construct a comprehensive evaluation system for salt-alkali stress tolerance of maize seed-lings and to screen superior salt-alkali tolerant maize germplasm resources,40 maize inbred lines were used as materials in this experiment,8 salt-alkali stress-related morphological indicators at the seedling stage were measured,and the principal component analysis,membership function method,cluster analysis,and stepwise regression were adopted for the comprehensive evaluation of salt-alkali tolerance of maize.A salt-alkali resist-ance prediction model was constructed to screen excellent salt-alkali tolerant germplasms.The results showed that among the 8 seedling morphological indicators,7 ones responded significantly to salt-alkali stress;princi-pal component analysis transformed the selected significant single indicators into 2 mutually independent com-prehensive indicators,with a cumulative contribution rate of 85.901%.Based on the comprehensive evaluation value of salt-alkali stress tolerance(D value),the 40 maize inbred lines were clustered into 4 groups with dif-ferent salt-alkali tolerance by systematic cluster analysis:1 was highly tolerant germplasm,6 were tolerant germplasms,14 were low-tolerant germplasms,and 19 were salt-alkali sensitive germplasms.Through stepwise regression analysis,the optimal prediction model for maize seedling salt-alkali tolerance was established.The evaluation system and prediction model constructed in this study could accurately assess the salt-alkali toler-ance of maize at seedling stage and provide theoretical basis and technical supports for screening salt-alkali tol-erant maize germplasms,studying resistance mechanisms,and breeding salt-alkali tolerant maize.