TITLE:
Genetic Enhancement of Indigenous Cowpea with Gamma-Ray Induced Trait Variation
AUTHORS:
Mathurin Tiergnin Dabiré, Minimassom Philippe Nikiéma, Djibril Yonli, Safiatou Sanna, Wossoguim Josué Gouba, Siébou Palé, Hamidou Traoré, Joseph T. B. Batieno, Varra Prasad, Zacharia Stewart, Jan B. Middendorf, Abhishek Rathore, Anupama J. Hingane
KEYWORDS:
Cowpea, Mutagenesis, Gamma Rays, Radio-Sensitivity, Phenotyping
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.15 No.8,
August
28,
2024
ABSTRACT: Production of cowpea (Vigna unguiculata (L.) Walp.), a staple legume crop in Sub-Saharan Africa, faces challenges due to biotic and abiotic constraints. Induced mutagenesis was deployed to create genetic variation in two cowpea varieties (KVX396-4-5-2D and Moussa local). The radio-sensitivity tests led to determe the lethal dose 50 (LD50) corresponding to 230 Gy and 220 Gy for KVX396-4-5-2D and Moussa local varieties, respectively. Dried seeds (M0) of each variety were gamma-ray irradiated with LD50 − 50, LD50 and LD50 + 50. M1 seeds were advanced to generate M2, M3 and M4 mutants using the single-seed-descent method. M4 mutant lines were evaluated in rain-fed conditions using a randomized complete block design to assess phenotypic differences. Data on seven qualitative and eleven quantitative traits were collected. The results indicated that the mutation induced variability in three qualitative traits: in KVX 396-4-5-2D mutant lines, with flower and seed color frequencies at 2.61% and 0.56% respectively, and pod dehiscence at a frequency of 0.24%. While in Moussa local mutants, a pod color changed at a frequency of 17%. ANOVA results revealed significant differences between mutants of both varieties for all quantitative traits, including photosynthetic parameters. Positive correlations were observed between leaf diameter and 100-seed weight, and between branch number and 100-seed weight. Hierarchical clustering revealed three clusters among KVX 396-4-5-2D mutants and six clusters among Moussa local mutants. Early maturity and high foliage were induced traits in Cluster 3 of KVX 396-4-5-2D mutants while high hundred-seed weight was induced in Cluster 6 of Moussa local mutants.