Two QTL for kernel number per spike identified from durum wheat

As one of the three yield components, kernel number per spike (KNPS) plays a key role in determining wheat yield. In this study, in combination with the previously constructed genetic map for a tetraploid wheat recombinant inbred line (RIL) population developed from the cross between a durum wheat and a wild emmer wheat and phenotype data from four environments, two major and stably expressed quantitative trait loci (QTL) for KNPS were identified. The phenotypic variation explained by these two QTL, Qknps-DW-3A.1 and Qknps-DW-3A.2, was up to 12.52% and 29.52%, respectively. The positive alleles were both from the durum wheat. Pyramiding analysis suggested that the combination of these two positive alleles has the largest effect on increasing KNPS. Comparison of physical interval for these two QTL with those reported previously showed that they may be novel loci. Genetic correlations between KNPS and other agronomic traits were also evaluated. Taken together, the two major and stably expressed QTL for KNPS from tetraploid wheat reported here they should be useful in wheat breeding.