Genetic Variability and Association among Grain Yield and Yield Related Traits in Tef [Eragrostis tef (Zucc.) Trotter] Germplasm Collections from Different Parts of Ethiopia

Abstract

Genetic variability is a key for successful selection of better crop varieties. The present study was, therefore, conducted to determine the magnitude of genetic variation, the broad sense heritability and expected genetic advance and the association among grain yield and yield related traits of recent tef germplasm collections from different parts of Ethiopia. Seventy tef genotypes (68 germplasm collections and 2 released varieties) were evaluated in 7-by-10 alpha lattice design with two replications at Holetta and Debre Zeit Agricultural Research Centers during the main cropping season of 2015. Data were collected on 18 quantitative traits. Analysis of variance showed highly significant (P<0.01) genotypic differences for all quantitative traits except for thousand seed weigh and the Genotype x Environment interaction was significant for 14 of the traits. This indicates that breeding for specifically adaptable varieties would be important. The genotypic coefficients of variability (GCV) ranged from 0 to 14.87 % while phenotypic coefficient of variability (PCV) ranged from 7.88 to 31.04 %. The lowest and the highest heritability estimates were observed for grain filling period (0%) and thousand seed weight (0%), and first basal culm internode diameter (46.07%), respectively. The estimates of genetic advance as percent of mean (GAM) ranged from 0% for grain filling period and thousand seed weight to 17% for number of spikelets per panicle and first basal culm internode diameter. Diameters of the first and second basal culm internodes, and panicle length showed relatively high heritability combined with high GAM; these traits can successfully be improved through selection. Moreover, the character of correlation showed selecting longer plant, longer panicle height and high spikelet number increases grain yield, and that higher number of first and second culm internode diameters minimize lodging index.