摘要
在氮素限制供应条件下，籼稻品种ＩＲ４２与广亲合粳稻品种Ｐａｌａｗａｎ剑叶及下位叶的平均叶绿素含量差异显著。叶绿素含量在Ｐａｌａｗａｎ／ＩＲ４２杂交Ｆ２代中呈正态分布。１０４个分布与１２条染色体的ＲＦＬＰ标记基因型之间表型平均值方差分析与区间作图分析结果表明，分别位于染色体２、４、７上的３个ＱＴＬ位于ＲＺ５８／ＲＧ１０２、ＲＧ１４３／ＲＧ３２９和ＲＧ６３４／ＲＧ６５０之间。与ＲＧ１４３及ＲＧ１０２连锁的ＱＴＬ具有显著加性效应，与ＲＧ１０２连锁的ＱＴＬ显示显著的显性效应。单个ＱＴＬ效应对群体变异贡献为５％以上。各标记位点不同基因型平均数比较表明，ＲＧ１４３和ＲＧ１０２位点表现为隐性基因效应，ＩＲ４２与Ｐａｌａｗａｎ基因型平均数差异显著超过群体平均数１０％以上，ＲＧ６３４位点ＩＲ４２与杂合基因型之间平均数差异也超过群体平均数１０％以上。非等位基因互作效应分析表明，染色体１０与９上的ＲＺ６２５与ＲＧ６６７位点之间具有显著的显性×显性交互效应，该效应可解释群体变异的７％以上。本研究首次报道水稻不同基因型在氮素限制供应条件下与叶绿素含量变异相关的数量性状位点（ＱＴＬｓ）及基因效应分析，用不同的研究材料及在不同的氮素条件?
Significant difference of chlorophyll content in completely extended flag and the second leaves under nitrogen stressed condition was found between two rice varieties,IR42, an indica variety and Palawan, a Japonica wide compatibility variety.The average amounts of chlorophyll content were normally segregated in the F2 population derived from a cross of Palawan/IR42. One hundred and four RFLP markers mapped on 12 chromosomes were used to identify putative QTLs underlying the variation in chlorophyll content. Orthogonal contrasts and interval mapping analysis indicated that three QTLs, located on chromosome 2, 4 and7, were flanked by RZ58/RG102, RG143/ RG329, and RG634/ RG650 respectively. Additive gene action was predominant at RG143 and RG102 loci, but dominant effect was significant at RG634 locus. The detected single QTL could explain more than 5% of variation in chlorophyll content in the population. Mean comparisons for genotypic classes of markers closely linked to the detected QTLs indicated that the marker loci RG143 and RG102 showed recessive gene action and the phenotypic differences between IR42 and Palawan genotypes at the two marker loci exceeded 10% of the population mean. The phenotypic difference between IR42 genotype and heterozygote at GR634 locus also exceed 10% of the population mean. Non-allelic interaction effect was detected between marker loci RZ625 and RG667 on chromosome 10 and 9 with significant (P<0.01) dominant×dominant gene action which could explain more than 7% of the whole population variation in chlorophyll content. This is the first time to report the QTLs underlying chlorophyll content variation in rice under nitrogen stressed condition. It is necessary to confirm the results by using different mapping populations under different nitrogen supply conditions.
