Genetic variability and heritability of nodulation, root morphology, yield contributing traits and their association in soybean

Soybean has a high nutritive value and numerous uses. An experiment was conducted to study the genetic variability and heritability of root morphology and nodulation traits along with other yield contributing characters of ten soybean genotypes to observe the relationship among the traits. The experiment was carried out in field conditions and data were collected from four months old plants. Three plants of each genotype were dug up from 40 cm soil depth to collect root traits. Analysis of variance revealed significant differences among soybean genotypes for plant height, ground area, leaves/plant, leaflets/plant, leaf area index, shoot fresh and dry weight, nodules/plant, nodule fresh and dry weight, root fresh and dry weight, primary root length, lateral roots/plant, pods/plant, 100-seeds weight, and yield/plant. A high heritability estimate was estimated for plant height (88.74%), ground area (68.57%), leaves/plant (64.15%), leaflets/plant (61.68%), leaf area index (77.01%), nodules/plant (60.30%), hundred seed weight (85.27%) and yield/plant (69.41%). Correlation analysis showed a significant relationship among the root and shoot traits. The principal component analysis revealed that the first five principal components (PC) explain 81.4% data variation. The soybean genotype PM-78-6-3-13 (S13) showed the maximum plant height, nodule fresh and dry weight, highest root fresh weight and the maximum number of lateral roots per plant, pods/plant and 100-seeds weight. The results suggested that looking at both nodulation and root traits could be useful for yield improvement in soybean.