Phenotypic diversity in the Ethiopian noug germplasm

Noug (Guizotia abyssinica (L.f.) Cass.: 2n = 30), a member of the Compositae family, is grown as an oilseed crop in Ethiopia. The crop grows best on poorly drained heavy clay soils. In this experiment, 157 noug accessions randomly sampled from different parts of the country were evaluated in a field test at Adet, Ethiopia in 1993, to estimate the phenotypic diversity index (H') for phenological (days to flowering, days to maturity) and morphological (leaf colour, leaf margin, stem hairiness, stem colour, angle of branching, plant height) characters. The phenotypic diversity was calculated using Shannon-Weaver diversity index (H') for the regions, provinces, characters, after pooling together all characters. The results of this study indicated that the phenotypic diversity index (H') of noug accessions was 0.61 for Western, 0.56 for Northern, 0.54 for Southern and 0.51 for Central and Eastern Ethiopia Province, while the highest diversity index was from Gojjam H' = 0.60, Welega H' = 0.57, and Shewa H' = 0.53. The phenotypic diversity index for the Nation was H' = 0.40. Most of the variations were due to differences among provinces for different characters than among regions. Based on the characters studied and small collections evaluated, the centres of diversity for noug appears to be in Gojjam, Welega and Shewa, and further exploration efforts should be undertaken in these regions. Key Words: Diversity index, genetic diversity, germplasm, Guizotia abyssinica Cass., oilseed (African Crop Science Journal: 2000, 8(2): 137-144