Genetic Advancement and Variability of Released Common Bean (Phaseolus vulgaris L.) Varieties from 1974–2009 GC in Ethiopia

Abstract

The efficiency of variety development can be determined with variability and genetic progress of released varieties. The aim of this study was to determine the variability and genetic advancement of common bean varieties. Randomized Completed Block Design was used to evaluate 15 varieties at Koga and Chefa in 2013. Cluster, principal, and biplot analysis including genetic parameter estimation were done following analysis of variance. Significant variation was observed among the varieties, and they are clustered into four groups. Seed color and size were found as an important factors for clustering of the varieties. Hawassa Dume and Nasir have red and small seeded, respectively, and clustered in one group. Similarly, Awash 1 and Awash Melka are both small white and clustered in one group. Hawassa Dume was highly similar to Nasir, and Red Wolayta with Dimitu, while a large distance was recorded between Awash Melka and Haramaya. Deme and Haramaya were found the most divergent and unique among the tested varieties. This is also reflected in biplot drown by principal components 1 and 2, which together accounted for about 82.022. Plant heights, seed weight, days to maturity, and harvest index have the largest contribution to the total variation of the varieties. Most of the traits have a high phenotypic and genotypic coefficient of variation, heritability, and genetic advance, and selection was effective in the breeding program. The breeding program has brought about 0.27 tonnes of seed yield increment or an annual rate of genetic progress of 0.0077 t ha−1 (0.37% ha−1 year−1). However, the breeding program should reconsider the breeding procedure as there are some varieties released in the same year with similar genetic potential.