Trait diversity, heritability and genetic advance in selected germplasm Lines of tef [Eragrostis tef (Zucc.) Trotter]

The genetic improvement of the Ethiopian cereal, tef, Eragrostis tef (Zucc. ) Trotter, depends upon the variability in the indigenous germplasm. A bi-r eplicated randomized complete block field experiment was, therefore, carrie d out at Debre Zeit and Alem Tena in Ethiopia during the 1996 main season t o study the pheno-morphic and agronomic trait diversity in 320 tef germplas m lines. All of the 17 traits assessed showed substantial (p less than or e qual to 0.001) variation among the lines. Genotypes and locations interacte d significantly (p less than or equal to 0.05) on 11 of the traits. At abou t 50% similarity level, the tef lines grouped into six major clusters of ni ne to 243 lines. Five principal components (PCs) extracted about 71% of the entire variation of the lines. About 28% of the total variance explained b y the first PC was due chiefly to variation in main shoot culm length, diam eters of the two basal culm internodes, panicle length and grain yield/pani cle. About 16% of the whole variance explained by the second PC originated mainly from variation in the length of the first and second basal culm inte rnodes, grain yield/plant. and peduncle length. The third PC accounting for about 12% of the entire variance resulted largely from variation in harves t index and shoot phytomass yield/plant. Across traits, the phenotypic and genotypic coefficients of variation varied in that order from about 2% for grain yield/panicle to 58% for number of fertile tillers/plant, and from le ss than 1% for diameters of the two basal culm internodes and grain yield/p anicle to 35% for panicle length. Estimates of broad sense heritability and genetic advance (as ratio of the mean) were highest for panicle length (71 %) and number of fertile tillers/plant (21%), respectively. But both of the se were lowest for the second basal culm internode diameter ( < 1%). Overal l, the study confirmed that tef is a highly versatile crop with broad trait diversity in the germplasm, and this offers ample opportunities for improv ement through breeding.