Genome-wide linkage mapping for canopy activity related traits using three RIL populations in bread wheat

Among yield contributing traits, the contribution of canopy activity related traits has been less studied. In this study, quantitative trait loci (QTL) for the normalized difference vegetation index (NDVI) at the seedling (NDVI-S) and grain filling (NDVI-10) stages and the chlorophyll (Chl) content at the grain filling stage (Chl-10) were mapped using three recombinant inbred line (RIL) populations of wheat derived from the following crosses: Doumai x Shi 4185 (D x S), Gaocheng 8901 x Zhoumai 16 (G x Z) and Linmai 2 x Zhong 892 (L x Z). In the three RIL populations, 6, 16 and 14 QTL were identified for NDVI-S, NDVI-10 and Chl-10, respectively. Furthermore, 6, 10 and 10 of the QTL were newly detected. Three QTL QNDVI-10.caas-4BS, QNDVI-10.caas-4DS and QChl-10.caas-4BS, were commonly detected in two populations. Twelve QTL clusters for both canopy activity related traits in the present study and grain yield (GY) related traits in our previous study were identified. NDVI-S is phenotypically and genetically correlated with thousand-kernel weight (TKW), which can be used to select lines with a high TKW. The QTL clusters harbouring QTL for canopy activity related traits and GY related traits are valuable in marker-assisted selection (MAS) of loci with pleiotropic effects. In addition, the stable QTL QNDVI-S.caas-1AL and QNDVI-10.caas-3B can be used to identify high NDVI lines at the seedling and grain filling stages, respectively. Our study provided new insight into the genetic architecture of the GY based on canopy activity related traits.