QTL analysis of leaf photosynthetic rate and related physiological traits in rice (Oryza sativa L.)

Photosynthesis is the primary source ofdry matter production and grain yield inrice. Study on genetics of photosynthesisand related physiological characters isvery important to rice physiologicalbreeding. In this study, a double haploid(DH) population derived from anther cultureof ZYQ8/JX17, a typical indica and japonicahybrid was used as genetic material. Netphotosynthetic rate, chlorophyll content,stomatal resistance and transpiration rateof the parents and DH lines wereinvestigated in flourishing tilleringperiod. The quantitative trait loci (QTLs)for each trait were analyzed based on theconstructed molecular linkage map of thispopulation. A total of 8 QTLs forphotosynthesis and related physiologicalcharacters were detected. Two putative QTLsfor net photosynthetic rate (qNPR-4 andqNPR-6) were mapped on chromosome 4 and 6,respectively. Three QTLs (qCC-1, qCC-3 andqCC-8) for chlorophyll content weredetected on chromosome 1, 3 and 8,respectively. One QTL for stomatalresistance (qSR-4) was identified onchromosome 4. Two QTLs for transpirationrate (qTR-4 and qTR-7) were detected onchromosome 4 and 7, respectively. TheseQTLs should accelerate the process ofbreeding new rice varieties with higherphotosynthetic capacity and higher yield.