Pheno-Morphological Characterization and Genetic Diversity Assessment of Grain and Vegetable Soybean (Glycine max. (L.) Merrill) Lines for Breeding Advancements

Abstract

This study presents for the first time, a thorough pheno-morphological characterization of ten soybean [Glycine max (L.) Merrill] lines (four grain type and six vegetable type). The vegetable soybean, also called as Edamame, and the grain type soybean, which underpin considerable genetic variation across traits such as flowering and pod-setting times, plant height, and seed size. Analyses of variance and clustering reveal obvious differentiation between vegetable and grain-type soybeans, particularly in traits such as height at the R7 stage, pod length, and branching patterns. The vegetable type exhibited faster plant development throughout reproductive stages and tended to be taller than the grain type. The study found characteristics, including test weight, plant height, and pods per plant, had higher phenotypic and genotypic coefficient of variation and, therefore, may serve as good candidates for selection breeding since these characteristics are based on a strong genetic constitution and to a lesser extent on environmental influences. The traits like number of pods per plant and test weight had high heritability and genetic advance and thus held great promise for improvement of productivity through selection. Important PCA explained traits were the plant height at the R7 stage, number of branches, and number of pods per cluster, which have high values for the breeding program. Hierarchical clustering also clumped the genotypes from other morphological characteristics which grouped them into clear distinct classification for the genetic diversity of this germplasm. In relation to this, one realizes that these soybean lines have genetic variability for significant breeding programs concerning increases in yield, adaptability, and resistance to stresses: biotic and abiotic.