水稻垩白和直链淀粉含量QTLqCR5/qAC5的定位和效应验证

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Abstract：To identify quantitative trait loci （QTL）associated with rice grain appearance and cooking/eating quality，a recombinant inbred line （RIL）population consisting of 181 lines was developed by crossing indica rice 931l and tropical japonica rice Cypress.A high-density genetic linkage map was constructed using resequencing data，and QTL mapping was performed based on evaluations of chalky grain rate，chalkiness degree，and amylose content in 2018 and 2019.A total of four QTLs for chalky grain rate，five QTLs for chalkiness degree，and six QTLs for amylose content were detected.A novel locus qCR5/qAC5 ，simultaneously affecting chalky grain rate and amylose content，was consistently detected within the chromosomal interval 18397268-20398241 bp on chromosome 5.In 2018 and 2019，the LOD values for chalky grain rate were 3.11 and 3.82 and the additive effects were -5.54 and -6.12 ，respectively.In 2018 and 2019，the LOD values for amylose content were 3.76 and 3.82，and the additive effects were -1.06 and -1.05 ，respectively. And the 9311 genotype of qCR5/qAC5 simultaneously increased both chalky grain rate and amylose content. Near-isogenic lines（NILs）with the 9311 genetic background were developed through backcrossing，and the genetic effcts of qCR5/qAC5 were validated using BCsF2 segregation population. This locus accounted for 20.9% of the phenotypic variation in chalky grain rate and 18.6% in amylose content. These findings lay a solid foundation for the fine mapping of qCR5/qAC5 and hold significant implications for genetic improvement of rice grain quality.

Key words： rice;grain chalkiness;amylose content;QTL

稻米品质主要包括外观品质、加工品质、蒸煮食味品质和营养品质。（剩余12196字）