Extent and pattern of genetic diversity for morpho-agronomic traits in Ethiopian sesame landraces (Sesamum indicum L.).

摘要

The aim of this study was to characterize and to estimate the extent of genetic variation of morphological attributes of Ethiopian sesame landraces (Sesamum indicum L.). An experiment was conducted in 2010 at Humera and Dansha, Ethiopia. Eighty one germplasm accessions were grown in a lattice design with 2 replications. Data on 17 traits were collected and analyzed. Differences among the accessions were significant for all of the traits at each location and pooled over location. The accessions were grouped into six clusters of different sizes. Cumulative effects of a number of characters dictated differentiation of the accessions into clusters. There was no definite relationship between geographic and genetic diversity as overlapping was encountered in clustering pattern among accessions from different parts of the country. Accessions from different regions might have similar genetic background and those from the same origin might also have different genetic diversity. Therefore, geographic diversity should not necessarily be used as an index of genetic diversity and parental selection should be based on a systematic study of genetic diversity in a specific population. Genetic distances among most of the clusters were significant that crosses between parents selected out of them are expected to generate desirable genetic recombination. Selection should also consider the special advantages of each cluster and each accession within a cluster. Future germplasm collection, conservation and breeding efforts should focus not only on inter-regional diversity but also on intra-regional diversity.