Avanços na ciência e tecnologia agrícola

Abstrato

Genetic Diversity in Ethiopian Sorghum (Sorghum bicolor L.) Germplasm Accessions Based on Major Quantitative Morphological Traits

Dagnachew Bekele

In Ethiopia, sorghum exists in tremendous diversity with an extremely broad genetic base for trait improvement. However, so far only a small number of sorghum germplasms have been characterized. In the present study, a total of 275 sorghum germplasms collected from major growing areas were characterized using 13 major quantitative traits. The result indicated the presence of extensive genetic diversity among test germplasms. Accessions from Tigray region were characterized by early flowering and maturity, short plant height, small number of leaves per plant and small leaf area. The highest mean number of days to 50% flowering and numbers of days to maturity were obtained for accessions collected from Oromiya region. Cluster analysis grouped test genotypes into six distinct diversity groups irrespective of their region of origin. The genetic distances between most of the clusters were highly significant (P<0.01). Maximum genetic distances were obtained between cluster 4 and 6, cluster 4 and 5, and cluster 1 and 6 with pair wise generalized square distance (D ) of 86.62, 51.56 and 46.69, respectively. Moreover, the first four principal components with eigenvalues greater than one explained 62.09% of the variation indicating the existence of significant genetic diversity among Ethiopian sorghum germplasms. Interestingly, from six distinct diversity groups, 50 diverse sorghum germplasms with good yield and yield related morphological traits were identified. Therefore, these genotypes can be utilized by the breeding programs to identify diverse parental combination for crossing to develop best varieties to maximize the genetic gain of the breeding program.