Molecular Diversity and Varietal Differences in Seedling Growth Rate among Cowpea Genotypes using SSR Markers

Full Length Research Paper

Molecular Diversity and Varietal Differences in Seedling Growth Rate among Cowpea Genotypes using SSR Markers

^1*ADEWUSI, Olamide Folake; ²ABDULWAHAB, Ahmed Ajeniyi AND ³OMIKUNLE, Oluwaseun Ayoola

^1,2Department of Biotechnology, Federal University of Technology, Akure, Ondo – State, Nigeria

³Wacot Ltd, Funtua, Katsina State, Nigeria

Corresponding author. E-mail: *Corresponding author. E-mail: ofadewusi@gmail.com

Accepted 5 December, 2022

Abstract

The present study aimed to evaluate genetic variability in seedling growth rate among cowpea genotypes using both phenotypic characteristics and Simple Sequence Repeat (SSR) markers. Twenty cowpea genotypes were sourced from the International Institute of Tropical Agriculture (IITA), Ibadan, Oyo State, Nigeria. Seedlings were cultivated in controlled conditions within the plant house of the Department of Biotechnology, Federal University of Technology, Akure. Analysis of variance indicated that most growth traits did not show significant differences, except seedling fresh and dry weights. The phenotypic coefficient of variation (PCV) exceeded the genotypic coefficient of variation (GCV) for all traits, with the highest values observed in seedling dry weight (41.20% and 33.62%, respectively), indicating considerable environmental influence. Heritability was generally low, except for seedling fresh weight (63.71%) and seedling dry weight (66.83%). All eight SSR markers were polymorphic, with CP09781 and CEDG093 yielding the highest allele numbers (17). Cluster analysis separated the genotypes into two groups, indicating limited genetic divergence. Consequently, these genotypes may not be ideal for hybridization in future breeding programs. However, seven genotypes (TVu-2300, TVu-16451, TVu-16117, TVu-16143, TVu-16123, TVu-15203, and TVu-12456) exhibited superior seedling growth traits, making them promising candidates for future cowpea breeding initiatives.

Keywords: Molecular diversity, varietal differences, seedling growth rate, SSR markers, cowpea genotypes