Phenotyping Identification and Comprehensive Evaluation of Fresh Spring Soybean Germplasms in Jiangsu Province

To make better use of vegetable soybean germplasms, discover potential excellent natural variation, and enrich fresh spring soybean germplasms, this study analyzed ten descriptive traits and eleven characteristics of 45 fresh spring soybean germplasms. The variation analysis, correlation analysis, principal component analysis, cluster analysis and comprehensive evaluation were carried out, and the disease resistance and taste quality were identified. The results of variability analysis showed that there were abundant variations among the eleven numerical traits, with the number of variations ranging from 2.77% to 31.57%. Among them, the coefficient of variation of bottom pod height was the largest, and the coefficient of variation of kernel rate was the smallest. Correlation analysis showed that plant height was significantly positively correlated with effective branches number, the number of main stem nodes, and the growth period. The number of effective branches was significantly positively correlated with the number of main stem nodes. The growth period and base pod height were significantly positively correlated. The number of main stem nodes, and the 100-seed fresh weight showed a very significant negative correlation. The 45 accessions were grouped into four major groups by the method of the sum of squared deviations, among which group II had the best comprehensive traits. The disease resistance analysis showed that 37 germplasms showed resistance to SMV SC3 strains, 33 germplasms showed high resistance to SC7 strains, and 20 germplasm showed resistance to both SC3 and SC7. The principal component analysis showed that the cumulative contribution rate of principal components such as plant type factor, growth period factor, yield factor, and kernel rate factor reached 66.65%. According to the contribution rate of the principal component value and its corresponding characteristic root value, the principal component comprehensive score of each variety was calculated, and the germplasms with the highest comprehensive score, yield traits, and disease resistance were comprehensively analyzed, JS-19, JS-28, JS-32 and JS-33 were screened out, which can be used as backbone parents for the selection of new fresh spring soybean varieties for innovatively breeding.