Evaluation of Agro-Morphological Trait Variation Among Cultivars and Accessions of Soybean (Glycine max) from the Guinea Savannah Zone of Nigeria

Abstract

The improvement of soybean cultivation could greatly benefit humanity and have a significant impact on reducing food insecurity. A breeding programme for any crop can explore favourable alleles more often by selecting features using morphological and molecular methods. This study evaluated the genetic variability of soybean accessions and cultivars using their agronomic and yield traits. The cultivars were popular varieties common among Benue State farmers, while twenty (20) accessions were obtained from IITA, Ibadan. The experiment was carried out in a completely randomised design with three replicates in perforated polythene bags containing two seeds per hole. Data on agro-morphological traits were taken. From the study, twenty-two (22) genotypes took 7 days to emerge, while two (2) (TGM-4691 and 713) appeared at 10.50 days. Cultivar_6, which took 28 days to emerge, was highly significant at (P<0.05). The plant height ranged from 2.31cm in TGM-1602 to 15.86cm in TGM-2231, with highly significant differences among the genotypes. TGM-4691 was significantly different in leaflet shape, while the number of nodes on the stem was higher in TGM-4476, with no nodes observed in TGM-4691, TGM-713, TGM-1139, and Cultivars_2. TGM-4476 had more pods (17.33), while Cultivars_6 had the fewest (0.33), and both had considerably longer days to 50% flowering (49 days) than any other genotype. TGM-1139, however, was found to produce flowers faster than any other genotype, at 28 days. TGM-4476 had the highest number of seeds per pod (26.00), which was significantly higher than all the genotypes. It was observed that all mean squares due to genotypes were highly significant for all traits (P=0.000), with the level of significance slightly reduced for the days to emergence (P=0.002). The number of nodes recorded the best heritability estimate of 98.36%, while the number of pods had the least (6.94%). Accessions TGM-2231, TGM-1605, and TGM-4476 showed excellent agro-morphological parameters and can be used for effective breeding programmes and commercial cultivation of soybeans for their high-yield traits in Benue State.