基于CSSL的水稻抽穗期QTL定位及遗传分析

抽穗期是水稻（Oryza sativa）品种的重要农艺性状之一,适宜的抽穗期是获得理想产量的前提。鉴定和定位水稻抽穗期基因/QTL,分析其遗传效应对改良水稻抽穗期至关重要。以籼稻品种9311（Oryzasativa ssp.indica‘Yangdao 6’）为受体,粳稻品种日本晴（Oryza sativa ssp.japonica‘Nipponbare’）为供体构建的94个染色体片段置换系群体为材料,以P≤0.01为阈值,对置换片段上的抽穗期QTL进行了鉴定。采用代换作图法共定位了4个控制水稻抽穗期的QTL,分别位于第3、第4、第5和第8染色体;QTL的加性效应值变化范围为–6.4––2.7,加性效应百分率变化范围为–6.4%––2.7%;qHD-3和qHD-8加性效应值较大,表现主效基因特征。为了进一步定位qHD-3和qHD-8,在目标区域加密16对SSR引物,qHD-3和qHD-8分别被界定在第3染色体RM3166–RM16206之间及第8染色体RM4085–RM8271之间,其遗传距离分别为13.9cM和6.4cM。研究结果为利用分子标记辅助选择改良水稻抽穗期奠定了基础。

Mapping and Genetic Analysis of Quantitative Trait Loci for Heading Date with Chromosome Segment Substitution Lines in Oryza sativa

Heading date (HD) is an important agronomic trait in rice. Appropriate HD is a prerequisite for attaining the desired yield level in rice breeding programs. Mapping HD quantitative trait loci (QTL) is important for rice improvement. We used 94 chromosome segment substitution lines (CSSL) derived from 9311/Nipponbare with 9311 as the recurrent parent for analysis of QTL controlling HD. By substitution mapping, 4 QTLs were mapped on rice chromosomes 3, 4, 5 and 8 (P≤0.01). The additive effect of the 4 QTL ranged from -6.4 to -2.7, and the additive effect percentages of the 4 QTL ranged from -6.4% to -2.7%. The additive effect of qHD-3 and qHD-8 showed the feature of major genes. To map qHD-3 and qHD-8, 16 pairs of primers were selected from simple sequence repeat primer pairs according to the rice physical map. qHD-3 was located in the interval between RM3166 and RM16206, which was 13.9 cM in genetic distance on rice chromosome 3, and qHD-8 was mapped in the interval between RM4085 and RM8271, which was 6.4 cM in genetic distance on rice chromosome 8. Mapping of QTL has laid a foundation for improving HD with marker-assisted selection in rice.