Genome-Wide Association Study for Spike Traits and Distribution of Two QTLs for Grain Number in Chinese Wheat Cultivars.

Main Content:
Spike traits play an important role in improving wheat yield. However, the application of reported spike-related loci remains unclear. Here, we assessed six spike-related traits across seven different environments using 406 wheat accessions.
A negative correlation was observed between two components of wheat yield: thousand kernel weight (TKW) and grain number per spike (GN). Nonetheless, TKW and GN were significantly higher in modern cultivars compared to landraces. Two reliable quantitative trait loci (QTLs) related to GN, QGN.nwafu-4A and QGN.nwafu-7A, were identified through genome-wide associate analysis. QGN.nwafu-4A showed pleiotropy on GN, kernel number per spikelet and spike length. Both elite haplotypes of QGN.nwafu-7A were prominently present in Chinese modern cultivars, particularly those released after the year 2000.