旱稻导入系碾磨品质和垩白粒率的QTL定位及其与土壤水分的互作分析

QTL Mapping and QTL×Environment Interactions of Milling Quality and Percentage of Chalky Grain in Upland Rice Introgression Lines under Upland and Lowland Environments

以优质水稻品种越富为遗传背景,具有旱稻品种IRAT109导入片段的271份导入系为材料,在水、旱田2个土壤水分环境下调查糙米率、精米率、整精米率和垩白粒率4个品质性状,研究旱田栽培对稻米品质性状的影响,进行QTL定位及基因型与环境的互作分析。结果表明,整精米率和垩白粒率易受土壤水分环境的影响,糙米率和精米率相对稳定。适当水分胁迫能提高稻米的整精米率,减少垩白粒率。利用混合线性模型,在水、旱田条件下共检测到4个品质性状的10个加性QTL和2对上位性互作QTL,分别位于第3、4、7、8和9染色体。3个加性QTL(qMR9、qHMR7和qHMR9)和一对上位性互作QTL(qHMR3～qHMR9)的贡献率大于10%。7个QTL与前人研究结果相一致。第4染色体RM1112～RM1272和第9染色体RM1189～RM410是QTL集中分布的区域。根据不同性状对干旱胁迫的反应特点,分别选择水、旱田条件下贡献率大、稳定的QTL或者具有旱田特异性的QTL,进行标记辅助聚合育种是培育抗旱、优质稻的一个有效途径。

Milling quality and percentage of chalky grain of rice （Oryza sativa L.） are important traits to producers and consumers The objectives of this study were to characterize the response of brown rice （BR）, milled rice （MR）, head milled rice （HMR）, and percentage of chalky grain （PCG） to upland water stress and to identify QTLs for the traits. A set of 271 introgression lines （ILs） （BCsF3）, carrying segments from upland cultivar IRAT109 in the background of lowland rice cultivar Yuefu, were used, and data were collected under upland and lowland environments. Great changes were detected between upland and lowland conditions in head milled rice and percentage of chalky grain, but relative stability in brown rice and milled rice. Head milled rice increased and percentage of chalky grain significantly decreased under upland condition. A total of ten additive QTLs and two pairs of digenic epistatic interactions QTLs for BR, MR, HMR, and PCG were detected on chromosomes 3, 4, 7, 8, and 9. The contribution of single QTL ranged from 1.81% to 17.49%, three QTLs （qMR9, qHMR7, qHMR9） and one pairs of digenic epistatic interactions （qHMR3-qHMR9） accounted for above 10% of the phenotypic variation. Six QTLs were no significant QTL × Environment interaction effects, seven QTLs were the same with those from previous reports, and two genomic intervals, RM1112-RM1272 on chromosome 4 and RM1189-RM410 on chromosome 9, were cluster regions of the QTLs. These co-localized QTLs and common QTLs will facilitate marker-assisted selection for grain quality traits in rice breeding.