Genotypic variability and heritability of agronomic traits in chemically mutagenized groundnut (Arachis hypogaea L.)

Abstract

It is crucial to know the heritable portion of variation as it provides variability component measure for the transmission of characters to the next generation. This study was aimed at the estimation of genotypic variability for agronomic traits in chemically mutagenized groundnut (Arachis hypogea L.) genotypes. Although groundnut ranks second among oil seed crops in the world after sun flower and also an excellent source of protein, carbohydrates minerals and antioxidant, the production in Nigeria is constrained by multiple factors including low genetic variability which impact the development of high-yielding varieties. Pot trials were carried out during 2025 and 2026 dry seasons under screen house at the teaching and research field, Department of Plant Science and Biotechnology, Bayero University, Kano. The seeds of the two improved groundnut genotype varieties (Samnut-24, Samnut-25) were collected from Kano State Agricultural and Rural Development Authority (KNARDA) and the two local varieties (’Yar-Gingo and ’Yar-Fara) were collected from Dawanau Market, Dawakin Tofa Local Government  Kano State. The experimental design used was Complete Randomized Design (CRD) and the seeds of each variety were sorted out and surface sterilized in 2.0% Sodium hypochloride for 1minute and then rinsed. The seeds were soaked in different concentrations of Hydroxyalamine Hydrochloride (0.00mM, 1.0mM, 2.0mM, 3.0mM and 4.0mM) or Sodium Azide (0.00mM, 1.0mM, 2.0mM 3.0mM and 4.0mM) for three (3) hours.  The results revealed significant variation among the genotypes. Genotypic (GCV %) coefficient of variation was observed lower than the phenotypic coefficient of variation (PCV %) for all the observed traits in this study, indicating that the environment significantly affect the expression of the traits. In Samnut-24 genotype, high genetic advance (GA) along with high heritability (H2) were observed in 100 Pod Weight and Biological Yield. Similarly, 100 Pod Weight of Samnut-25 genotype scored highest genetic advance (GA) of (32.95) and heritability (H2) of (61.92%) indicating genetic improvement through direct genotypic selection. It is recommended that, farmers should adopt the use of genotypes with expressed additive gene action developed from variable components for crop improvement.