Fine Mapping of Drought Resistance QTL on Chromosome 2 in Rice

Abstract

In rice breeding research, drought resistance (DR) is one of the most important target traits for variety improvement under ever-increasing severe drought situation in the whole world. Identification of the physiological character and grain yield QTLs directly related to DR will provide useful marker information for developing with DR rice variety via marker-assisted selection (MAS). The 87 introgression lines (ILs) selected from 269 advanced backcross introgression population derived from Zhenshan 97B/IRAT109 in the Zhenshan 97B background were planted in drought facilities for mapping QTLs affecting physiological characters and grain yield under irrigation and drought stress conditions. Twenty QTLs affecting leaf water potential (LWP), canopy temperature (CT), basal culm thickness (BCT), 100-grain weight (HGW), spikelets number per panicle (SN), and spikelets density were identified, which could be grouped into three types based on their behaviors. Type I included seven QTLs which were detected under both conditions; type II consisted of four QTLs which were mapped only in the control condition; and type III consisted of two QTLs which were induced by drought and detected only under the stress. The seven QTLs detected under both environments and the two QTLs detected under drought stress could directly contribute to DT and be used in rice breeding for DT by MAS. Source: cab