Pollen Parameters Estimates and Molecular Characterisation of Selected Varieties of Soybean [Glycine max (L.) Merril]

Abstract

Background and Objective: Soybean (Glycine max) is a very important leguminous crop known for its highly valued protein and oil. Genetic variability is the basic requirement for crop improvement, it provides a wider scope for selection. Selection through studies of pollen behaviours and molecular characterisation increases the frequency for favourable alleles which can be explored in a breeding programme for the crop. Materials and Methods: Nineteen varieties of soybeans were collected from the gene bank of the International Institute of Tropical Agriculture (IITA), Ibadan. The varieties were evaluated for their pollen parameters following standard procedures. Results: Eleven distinct genotypes obtained from the pollen studies were further evaluated for genetic diversity using a simple sequence repeat (SSR) molecular marker. Most of these varieties were seen to be highly fertile (26.70-84.60%). The highest sterility value was recorded in TGX-2010-11F with a value of 73.3% and the least value of 15.4% was recorded in TGX-2018-5E. TGX-2007-3F produced significantly (p<0.05) highest pollen diameter (0.27 µ). Molecular diversity of 11 selected varieties from the initial twenty varieties using simple sequence repeat DNA marker generated 150-320 base pair with six primers. Genetic similarity among the varieties varies from 0.17-4.09 with an average gene diversity of 0.28. Clustered dendrogram of the 11 accessions revealed two major clades (TGX-1987-62F and TGX-2011-6F). Conclusion: The high genetic variability obtained for both pollen parameters and molecular characterisation indicate that soybean could be selected for those heritable traits and used as a tool for the improvement of the crop.