Screening and Evaluation of Salt-Tolerant Wheat Germplasm Based on the Main Morphological Indices at the Germination and Seedling Stages

The successful screening and evaluation of salt-tolerant germplasm at the germination and seedling stages is of great importance for promoting the breeding of wheat varieties with salt tolerance. In this study, 70 wheat varieties bred in different regions were evaluated for salt tolerance through hydroponic exposure to different concentrations of salt. The relative water absorption, water absorption rate, dehiscence rate, germination rate, and germination index of seeds, and plant height, root length, stem diameter, and biomass of seedlings were determined at the germination and seedling stages of wheat, and the salt tolerance was identified and evaluated using multivariate statistical analysis. The germination ability and seedling growth potential of wheat germplasms decreased with the aggravation of salt stress. Based on the comprehensive salt tolerance index at the germination stage, our study identified 35 varieties to be salt-tolerant. There were nine varieties further screened for having strong salt tolerance according to the comprehensive salt tolerance index at the germination and seedling stages. SN41, Emam, YN301, and JM262 were superior in salt-tolerance, and YM39, LM30, JM60, YN999, and SD29 were salt-tolerant. Our study suggests that the biomass of seedlings can be used as a key parameter for assessing wheat germplasm's ability to withstand salt. Our results can provide some basic materials for cultivating new germplasm with salt tolerance and excavating the related genes of wheat.