Abiola Toyin Ajayi , Vincent Bamidele Akinmola , Opeyemi Hallelujah Osin , Oluwatoyin Sunday Osekita

Department of Plant Science and Biotechnology, Adekunle Ajasin University, Akungba-Akoko, Nigeria
Author    Correspondence author
Biological Evidence, 2026, Vol. 16, No. 6   
Received: 11 Sep., 2026    Accepted: 21 Oct., 2026    Published: 06 Nov., 2026

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Cowpea (Vigna unguiculata [L.] Walp) is a nutritionally important grain legume whose productivity is constrained by a narrow genetic base. Therefore, this study aimed to induce genetic variability using hydrogen peroxide (HP) and evaluate the character associations among the resulting genotypes. Cowpea seeds (TVu-17327) were treated with 0%, 20%, and 40% HP for 24 hours and evaluated in the M₁ (2024) and M₂ (2025) generations under field conditions using a randomized complete block design. Data were collected on growth, yield, and chlorophyll-related traits. Genetic parameters, including genotypic and phenotypic coefficients of variation (GCV and PCV), broad-sense heritability, genetic advance (GAM), and Pearson's correlation coefficients, were estimated following analysis of variance. HP significantly affected most growth, yield, and chlorophyll-related traits in both generations. The 20% treatment produced the highest number of pods per plant (21.46 in M₁; 10.08 in M₂), while the 40% treatment recorded the highest total chlorophyll content (52.79 µM in M₁) and seeds per pod (14.00 in M₂). Compared with M₁, the M₂ generation exhibited higher emergence, seeds per pod, and pods per peduncle, but lower seed yield per plant. Broad-sense heritability was high (≥60%) in both generations, except for the number of main branches, which consistently exhibited low and moderate heritability, respectively, in M₁ and M₂. High GAM (>20%) for peduncle length, number of peduncles, number of pods, seed weight, seeds per plant, and chlorophyll parameters in M₂ indicates substantial potential for effective selection and genetic improvement. Fewer but more pronounced correlations among yield and chlorophyll traits in M₂ reflect trait reorganization following segregation. HP effectively induced variability in cowpea, with the M₂ generation providing greater opportunities for selecting superior genotypes for yield and physiological traits.

Cowpea; Genetic variability; Hydrogen peroxide; Mutation breeding; Selection