为了揭示水稻(Oryza sativa)茎鞘非结构碳水化合物(nonstructural carbohydrate, NSC)积累与转运的遗传基础, 在大田直播条件下, 利用来源于Lemont/特青的重组自交系群体, 对5个相关性状进行了QTL定位。始穗期和成熟期共检测到3个茎鞘NSC含量QTL, 分别位于第1、9和12染色体上, 贡献率分别为13%、7%和7%, 增效等位基因均来自特青。检测到的2个NSC转运率QTL均位于第12染色体上, 贡献率分别为8%和14%。检测到的结实率和千粒重QTL分别为3个和4个, 3个结实率QTL的贡献率分别为9%、24%和6%, 4个千粒重QTL的贡献率分别为14%、11%、12%和13%。进一步的分析表明,来自Lemont的等位基因降低成熟期茎鞘NSC含量的同时却能提高NSC转运率、结实率和千粒重, 而来自特青的等位基因对NSC转运率和结实率均有增效作用, 这为性状间表型相关提供了重要的遗传解释。

We aimed to understand the genetic basis of nonstructural carbohydrate(NSC) accumulation and translocation in rice culms and leaf sheaths. Quantitative trait loci (QTL) for 5 related traits were mapped with use of a recombinant inbred line derived from a cross between Lemont (japonica var.) and Teqing (indica var.) under direct sowing. Three QTL affecting NSC content at heading and maturity were detected on chromosomes 1, 9 and 12, explaining 13%, 7% and 7%, respectively, of the phenotypic variation. The Teqing alleles increased the trait value at all three QTL. Two QTL for NSC translocation rate were identified on chromosome 12 and accounted for 8% and 14%, respectively, of the total variation.The number of QTL for seed-setting rate and 1000-grain weight were 3 and 4, respectively. The amount of variation explained by the seed-setting rate QTL were 9%, 24% and 6%, and that explained by the 1000-grain weight QTL were 14%, 11%, 12% and 13%. The Lemont allele decreased NSC content at maturity but increased NSC translocation rate, seed-setting rate and 1000-grain weight at the region near RM277 on chromosome 12. The Teqing allele increased both NSC translocation rate and seed-setting rate at the region near OSR20 on chromosome 12, which provides a genetic explanation for the close correlations among the traits.