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| Format: | Recurso digital |
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Zenodo
2025
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| Online Access: | https://doi.org/10.5281/zenodo.16788724 |
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Table of Contents:
- <p>ABSTRACT: Drought stress significantly reduces cowpea yields in Africa,<br>necessitating the development of drought-resilient genotypes. This study<br>evaluated the genetic variability and drought tolerance of nine ethidium<br>bromide (EtBr)-derived cowpea genotypes at the M7 generation under<br>control and drought stress conditions. The study was conducted in a<br>randomized complete block design and assessed morphological and yield<br>traits alongside ten drought tolerance indices (DTIs). Significant effects of<br>genotype and genotype × treatment interactions were observed for most<br>traits, except peduncle length and 100-seed weight. Genotypes G1 and G2<br>demonstrated superior drought tolerance, reflected by high values for key<br>DTIs such as Geometric Mean Productivity (GMP), Stress Tolerance Index<br>(STI), and Drought Resistance Index (DRI), and consistently maintained<br>higher yields under stress. In contrast, G5 and G7 showed poor<br>performance under drought, with lower yields and DTI values. Broadsense<br>heritability was high for important traits, including plant height<br>(84.41%) and seed yield per plant (60.08%), indicating strong genetic<br>control. High genotypic and phenotypic coefficients of variation,<br>particularly for seed yield per plant (GCV: 71.54%, PCV: 92.29%), suggest<br>considerable potential for selection-based improvement. The heatmap<br>analysis revealed that reproductive traits, particularly seed yield, number of<br>pods, and peduncle length, are strongly associated with key DTIs, making<br>them valuable targets for selection under drought stress. These findings<br>underscore the effectiveness of EtBr-induced mutagenesis in generating<br>genetic variability and enhancing drought resilience in cowpea. Future<br>breeding programs should prioritize genotypes like G1 and G2, integrating<br>key drought-related traits and indices to develop high-yielding, climate-resilient<br>cowpea varieties suitable for drought-prone regions in sub-Saharan<br>Africa.</p>