Genetic diversity and eco-geographical distribution of Eleusine species collected from Ethiopia.
Eleusine is a small grass genus with three basic chromosome numbers (x=8, 9 and 10) and comprises of eight species including E. coracana subsp. coracana, (finger millet), which is an important subsistence crop in Africa and India. Research on these species could assist the development of high yielding and multiple stress tolerant variety(s) of the cultivable species, and also guide development of strategic genetic resource management and utilisation of the genus. A total of 72 accessions, sampled from five major species, E. coracana (including both E. coracana subsp. coracana and E. coracana subsp. africana), E. intermedia, E. indica, E. multiflora and E. floccifolia were analysed for genetic variation and inter-relationships using 20 microsatellite markers. All the SSR markers displayed high genetic polymorphism, with polymorphic information content ranging from 0.46 (UGEP110) to 0.91 (UGEP66). A total of 286 alleles were observed with an average of 14.3 alleles per locus. Classic F-statistics revealed the highest intra-specific polymorphism recorded for E. africana (32.45%), followed by E. coracana (16.83%); implying that genetic polymorphism is higher in the cultivable subspecies and its wild relatives, than the other species. Allelic frequency based inter-species genetic distance analysis, showed wider genetic distance between E. indica and E. multiflora (0.719); a narrow genetic distance between E. coracana subspecies africana and E. coracana subspecies coracana (0.3297). The weighted neighbor joining-based clustering revealed that the majority of the accessions in a species share strong similarity and are grouped together than do accessions of inter species.
Key Words: Eleusine, microsatellite, polymorphism