Phenotypic Diversity in Tef [Eragrostis Tef (Zucc.) Trotter] Accessions from Different Regions of Ethiopia

Abstract

Seventy nine tef landraces collected from ten administrative zones and seven altitude classes were planted with two improved varieties in simple lattice design at Gute and Bako in 2007 and 2008, respectively to assess the patterns of genetic variation for quantitative and qualitative traits. Loose and fairly loose panicle forms; gray lemma color and brown seed color were abundant across all regions and altitude classes while compact and semi-compact panicles, red and purple lemma color and white seed color were less frequent. Higher Shannon diversity indices were observed for East Gojam, East Wollega, Horro Guduru Wollega, Illubabor and Jimma collections. Mean squares due to genotypes were significantly different for all traits except number of culm internodes, number of spikelet per panicle and number of fertile floret/spikelet at top of the panicle. Genotypes and environments interacted highly significantly (P≤0.01) for number of panicle branches, lodging index, above ground biomass weight, grain yield per plant and harvest index. About 73% of the entire diversity among population was explained by the first six principal components (PCs), of which the first PC explained about 31% of the variation. This originated mainly due plant height, panicle length, culm length, first and second culm internode diameters, days to panicle emergency and days to maturity. Similarly, about 91% and 90% of the variations among regions of origin and altitude classes were explained by the first five and three PCs, respectively. At 50% similarity level, 11 clusters were formed, containing 2-33 landrace populations per cluster, while six tef landraces remain solitary. There is no cluster formed solely either from tef populations of a given region, tef populations collected from similar agro-ecological zones or populations collected from areas with similar soil type. Some neighboring regions were grouped together in one cluster, implying that there are extensive informal seed exchanges or inter-regional migration of farmers with their seed. Some other regions show strong similarity while they are geographically very far away from each other (for instance, South Wello and Horro Guduru Wollega). Six altitude classes were grouped in to two main clusters at about 50% similarity level. However, tef landraces collected from altitude class below 1576 m.a.s.l (class I) remain un-grouped.