Variation for kernel number and related traits in triticale (x Triticosecale Wittmack)

Abstract

Assessing the existence and extent of genetic variation in kernel number per m2 (KNO) and in KNO-related traits is necessary both for overcoming sink limitations through breeding and in order to correctly model triticale grain yield. A set of 112 advanced breeding lines derived from various crosses between winter and spring hexaploid triticales was grown for 2 years in a field experiment to evaluate genetic variation and heritability for KNO, chaff weight per m2 at maturity (CHAFFW) and number of kernels per unit weight of chaff (K/CHAFF). Genetic correlations were also calculated between these traits and grain weight and yield. K/CHAFF (but not CHAFFW) exhibited a high level of genetic variation and a low contribution of the genotype by environment interaction component to the overall variance and was highly heritable. There was no detectable genetic correlation between K/CHAFF and CHAFFW; however, K/CHAFF was correlated with KNO (r = 0.66, P < 0.001). K/CHAFF fulfils the major requirements of an indirect screening trait for KNO and of a genetic coefficient in modelling.