Genetic Dissection of Nonstructural Carbohydrate Accumulation and Translocation in Rice Culms and Leaf Sheaths Under Direct Sowing
直播水稻茎鞘非结构碳水化合物积累与转运的遗传剖析

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.