Heritabilities and selection responses for yield and yield associated traits in spring wheat.

摘要

Estimation of genetic variances and heritabilities are critical for predicting genetic improvement in yield and other related traits. A set of 25 randomly selected experimental wheat lines was evaluated for two years (2001-02 and 2002-03) in Peshawar, Pakistan. Data taken on spikes per m2, spike length, grains per spike, 1000-grain weight and grain yield were analysed across years using a random effects model. Genetic variation among lines was highly significant (P<0.01) for all traits, but genotype x year interaction was significant (P<0.05) for spike length only. Genetic variances for all traits were 1.5 to 6-times greater than the genotype x year and/or error variances. Heritability estimates were comparatively higher ranging from 0.63 to 0.91. Using 20% selection intensity, selection differentials were positive for all traits. There was close correspondence between the observed and expected responses to selection confirming the significance of heritability estimates in predicting the genetic improvement for various traits in multi-year and/or location evaluation trials of experimental lines.