Comprehensive Evaluation and Index Screening of Salt-Alkali Tolerance during the Seedling Stage of Cyperus esculentus

LI Chunxin; ZHAI Yunru; WANG Shufeng; CHEN Xiangong; ZHENG Mei; WANG Meng; ZHANG Ge; WANG Huiwei; YUAN Tianyou

doi:10.15933/j.cnki.1004-3268.2025.07.005

Abstract：To clarify the salt-alkali tolerance characteristics of tiger nut(Cyperus esculentus)at the seedling stage and establish precise evaluation indicators and a relevant mathematical model,18 trait indices including germination rate,plant height,root length,root number,plant biomass,plant water content,chlorophyll content,superoxide dismutase(SOD)activity,and soluble protein content were measured for 66 tiger nut germplasm resources under 5 g/kg mixed salt-alkali stress after 15 days of germination.Comprehensive analytical methods,including correlation analysis,principal component analysis(PCA),membership function,grey relational analysis,and stepwise regression analysis,were employed to assess the stress tolerance performance of different materials and establish an evaluation system.The results showed that the variation in salt-alkali tolerance coefficients among different traits ranged from 9.79%to 58.57%,with the coefficient for root dry mass exhibiting the greatest variability and that for relative water content demonstrating the smallest variability.PCA transformed the 18 original indicators into six principal components,which cumulatively accounted for 86.783%of the total variance.Based on the comprehensive evaluation D-value,the 66 germplasm resources were classified into five tolerance levels:extremely strong,strong,moderate,weak,and sensitive.Classification criteria were defined,identifying two germplasm resources with extremely strong tolerance and 12 salt-sensitive germplasm resources.Cultivars Yu Yousha 2 and Yu Yousha 3 were both classified as strongly salt-alkali tolerant materials.Using stepwise regression analysis,a mathematical model for evaluating salt-alkali tolerance at the seedling stage was established.This model demonstrates that by measuring and calculating the salt-alkali tolerance coefficients of total fresh weight,relative water content,root number,total chlorophyll content,plant height,and SOD activity,the D-value can be estimated using the regression equation to assess the salt-alkali tolerance of tiger nut germplasms at the seedling stage.This study provides essential materials,methodological support,and a robust evaluation framework for subsequent research on salt-alkali stress tolerant mechanisms and breeding of tiger nut varieties.