Correlation and Quantitative Trait Loci Analyses of Total Chlorophyll Content and Photosynthetic Rate of Rice(Oryza sativa) under Water Stress and Well-watered Conditions

In order to explore the relevant molecular genetic mechanisms of photosynthetic rate(PR) and chlorophyll content(CC) in rice(Oryza sativa L.),we conducted a series of related experiments using a population of recombinant inbred lines(Zhenshan97B × IRAT109).We found a significant correlation between CC and PR(R = 0.19) in well-watered conditions,but no significant correlation during water stress(r = 0.08).We detected 13 main quantitative trait loci(QTLs) located on chromosomes 1,2,3,4,5,6,and 10,which were associated with CC,including six QTLs located on chromosomes 1,2,3,4,and 5 during water stress,and seven QTLs located on chromosomes 2,3,4,6,and 10 in well-watered conditions.These QTLs explained 47.39% of phenotypic variation during water stress and 56.19% in well-watered conditions.We detected four main QTLs associated with PR;three of them(qPR2,qPR10,qPR11) were located on chromosomes 2,10,and 11 during water stress,and one(qPR10) was located on chromosome 10 in well-watered conditions.These QTLs explained 34.37% and 18.41% of the phenotypic variation in water stress and well-watered conditions,respectively.In total,CC was largely controlled by main QTLs,and PR was mainly controlled by epistatic QTL pairs.