QTL analysis of Chlorophyll Content at different growth stages of Barley

Chlorophyll content is not only the main factor determining the photosynthetic efficiency, but also an important character affecting barley yield. In this study, the 134 recombinant inbred lines (RILs) obtained from the cross of H602 and Golden Promise (GP) were used to systematically investigate chlorophyll content at tillering stage, heading stage and grain-filling stage. The high-density genetic map constructed by SLAF-seq technology was used for QTL analysis, and a total of 29 QTLs related to chlorophyll content were detected. Among them, 7 QTLs, explaining 9.9 − 24.9% phenotypic variations were detected at tillering stage, which were distributed on chromosomes 2H, 5H and 7H. 11 QTLs were detected at heading stage and grain-filling stage, which were distributed on chromosomes 2H, 3H, 5H, 6H and 7H, and accounted for 12.1 − 38.3% and 13.6 − 25.8% phenotypic variations, respectively. The contributions to the maximum phenotypic variations at heading stage and grain-filling stage were higher than that at tillering stage, indicating that the chlorophyll contents in the second leaves from the top at heading stage and flag leaves at grain-filling stage were higher, which played an important role in the accumulation of products. In addition, qTC5, qHC7 and qGFC6 were detected for three consecutive years and less affected by the environment, indicating that the three main QTLs controlled the chlorophyll content at tillering stage, heading stage and grain-filling stage respectively, and were stably inherited.