Variability, heritability and genetic advance in pheno-morphic and agronomic traits of tef [Eragrostis tef (Zucc.) Trotter] germplasm from eight regions of Ethiopia

Abstract

One hundred and twenty tef Eragrostis tef (Zucc.) Trotter, germplasm lines from eight regions of Ethiopia were field evaluated in two randomized complete blocks at Debre Zeit and Melkassa during the 1995/95, and at Debre Zeit and Alem Tena during the 1996/97 main seasons. The objectives were to assess the extent and pattern of their diversity with respect to 17 pheno-morphic and agronomic traits, and to obtain an insight into the broad sense heritability (H) and genetic advance (GA) expectations of the various traits. Discernible (p≤ 0.05) variability among regions and among genotypes within regions were observed in seven and nine of the traits, respectively. In the combined analysis of variance over environments, genotypes showed substantial (p ≤ 0.05) variation in all traits, and genotypes and environments interacted significantly on nine of the traits. The phenotypic and genotypic coefficients of variation varied in that order from about 3 % for days to maturity to 28 % for grain yield/plant, and from less than 2 % for days to maturity to 15 % for number of fertile tillers/plant. Estimates of H were lowest for shoot phytomass/plant (17 %) and highest for panicle length (75 %). The minimum GA expectations were for days to maturity (2 %) and the maximum was for number of fertile tillers/plant (23 %). About 67 % of the gross phenotypic diversity in the germplasm was explained on the basis of four principal components (PCs). Up to 28 % of the variance extracted by the first PC was due mainly to variations in the second and first basal culm internode diameters, culm and panicle length, days to panicle emergence, and number of panicle branches and fertile tillers/plant. Largely variations in the length of the two basal culm internodes and grain yield/plant contributed to 19 % of the whole variance accounted for by the second PC. Generally, the study showed that there is ample genetic variation in the genotypes evaluated and this presents a valuable base for use in the improvement work.