水稻RZ54/南京11 F2群体抽穗期QTL分析

[目的]挖掘新的控制早熟性的QTL，为早熟性的遗传机制研究和分子育种提供新的基因资源。[方法]选择熟期差异明显的2个品种（早熟品种‘RZ54’和相对迟熟品种‘南京11’）进行杂交，构建F2群体，利用分子标记构建遗传连锁图谱，进行抽穗期QTL定位。[结果]利用141个具有多态性的SSR和Indel标记对由184个株系组成的RZ54/南京11的F2群体进行基因型检测，构建了全长为1 741.4 cM、平均图距为12.35 cM、覆盖水稻12条染色体的遗传图谱。在南京自然光温（高温长日照）环境下检测该群体的抽穗期QTL，结果在第6、7、8及11染色体上发现5个与抽穗期有关的QTL位点，分别命名为qHd-6、qHd-7、qHd-8-1、qHd-8-2和qHd-11。其中在qHd-8-1效应区段内存在已报道的基因DTH8，在其他效应区段内未发现已报道的抽穗期基因。但已报道的Hd1和Ghd7基因分别位于qHd-6和qHd-7位点附近，在第6、7染色体检测到的QTL可能来自这2个基因的效应。因此，qHd-8-2和qHd-11可能是新的抽穗期QTL位点。[结论]通过遗传图谱构建和QTL位点分析，检测到了新的QTL位点，为下一步精细定位和图位克隆奠定了基础，也为抽穗期的分子标记辅助育种提供了新的基因资源。
[Objectives]This study aims to find new QTL controlling heading date which was detected in RZ54/Nanjing11 F2 population under natural-field condition in Nanjing.[Methods]In this study,we utilized two materials with different heading date, ‘RZ54’ and ‘Nanjing 11’,to generate a segregation F2 population and construct molecular linkage map. On the basis of that QTL controlling heading date was detected and analyzed.[Results]A molecular linkage map,consisting of 141 markers spanning a total of 1 741.4 cM and covering twelve chromosomes,with an average marker interval of 12.35 cM,was constructed in 184 lines of RZ54/Nanjing11 F2 population. Marker order on the chromosomes matched well with that of the published map. QTL analysis was performed under natural high temperature long day condition in Nanjing. We found that there were five significant sites exist at the sixth,seventh,eighth and eleventh chromosome,named qHd-6,qHd-7,qHd-8-1,qHd-8-2 and qHd-11 respectively. Further analysis revealed that a known gene,DTH8,is located at the identified qHd-8-1 site. There were no reported heading date genes located at other identified sites. However,a known gene Hd1 is located downstream of the identified qHd-6 site,and another known gene,Ghd7,is located upstream of the identified qHd-7 site. The QTL detected on the sixth and seventh chromosome may be derived from the effects of these two genes. These results suggest that the qHd-8-2 and qHd-11 sites are the newly discovered heading date QTL.[Conclusions]New QTL loci were identified in this study,which laid the foundation for further fine mapping and map-based cloning. It also provided new gene resources for molecular marker-assisted breeding of heading date