MORPHO-PHYSIOLOGICAL CHARACTERIZATION OF SOYBEAN GENOTYPES UNDER SUBTROPICAL ENVIRONMENT

Soybean is a promising oilseed crop in rice-based cropping systems in South and Southeast Asia. In spite of immense scope of its expansion, the crop is not being popular to the farmers because of poor yield of the existing cultivars. Therefore, this study evaluated eighty-soybean genotypes of diverse growth habits with a view to searching genotype(s) of desirable morpho-physiological characters and high yield potential. Sixteen quantitative plant traits were evaluated to classify the genotypes into different groups using various multivariate methods. A wide range of variation was found in almost all qualitative plant traits. The study reveals that plants tend to become taller as the phenological cycle is longer. Seed yield was the product of the number of pods per plant, pod weight and seeds per pod. The first three components of principal component analysis explained 75% of the total variations of the soybean genotypes. Using Dendrogram from cluster analysis, the genotypes were grouped into six clusters. The maximum number of genotypes was concentrated in cluster 5 followed by clusters 4. The phenology, plant height, the number of pods and seed yield were the important discriminating variables in grouping the genotypes. The number of pods per plant displayed the principal role in explaining the maximum variance in the genotypes. The clustering pattern of the genotypes revealed that the genotypes under cluster 2 and cluster 6 were long statures, late maturing and produced higher seed yield. The genotype G00003 under cluster 2 is the best entry giving the highest seed yield. From cluster 6, the genotype G00209 could be the better choice for much better seed yield. The cluster 3 genotypes were comparatively early maturing and gave reasonable yield. It is concluded that the genotypes under clusters 2 and 6 and 3 can be important resources for developing a high yielding variety and sustainability of growing soybean in the subtropical conditions.