Selection Index for Improving Grain Yield and Related Traits in Tef (Eragrostis tef)

Selection indices provide useful information to breeders who usually base selection on means and ranks. Knowledge on selection criteria for improving tef grain yield is very limited. Accordingly, the objective of this study was to develop selection criteria for improving tef grain yield through indirect yield component selection via a selection index. Different trait combinations along with three selection methods (based on best linear unbiased predictors (BLUPs), plot basis and mean of genotypes) were studied at two locations, Melkassa and Debre Zeit, Ethiopia, in 2003 and 2004, using recombinant inbred lines (RILs) of tef crosses. Selection based solely on grain yield was estimated to be less effective than selecting based on grain yield, panicle seed weight and shoot biomass. BLUPs showed smaller mean values for panicle length and shoot biomass compared with selection based on individual plots. Selection based on individual plots selected higher yielding genotypes than BLUPs method. Higher gains were obtained from selection based on grain yield, shoot biomass, panicle seed weight, panicle length and lodging index, followed by selection based on grain yield, shoot biomass and days to maturity. The use of a selection index made it possible to detect desirable correlated responses in grain yield, shoot biomass, panicle seed weight and panicle length. This suggested that the use of a selection index might be a useful indirect selection criterion to improve grain yield. Further research is required to validate the results of the present study.