水稻黑条矮缩病抗性QTL定位

发掘水稻黑条矮缩病的抗性基因有助于抗病品种的选育,减少黑条矮缩病对水稻生产的危害。本研究构建了包含222个家系的L5494/IR36重组自交系群体。对该群体进行黑条矮缩病的田间诱发鉴定,抗性亲本IR36发病率为28.70%,感病亲本L5494发病率为84.26%,群体发病率范围为11.21%～89.81%。利用134对分子标记构建覆盖12条染色体的遗传连锁图谱,总遗传距离为1475.97 cM,平均标记间距为11.1 cM。利用QTL IciMapping 4.0对抗黑条矮缩病QTL进行分析,共检测到4个QTL,其中第1、第2、第9染色体上QTL的表型贡献率分别为12.64%、16.00%和8.43%,抗病等位基因来自抗病亲本IR36;第6染色体上QTL的表型贡献率为10.82%,抗病等位基因来自感病亲本L5494。在此基础上,利用93-11为供体、日本晴为背景的近等基因系材料,在qRBSDV-1定位区间内检测到来自93-11的抗性QTL。本研究结果为水稻黑条矮缩病抗性基因定位及分子标记辅助选择育种提供借鉴。

Mapping of QTLs for resistance to rice black-streaked dwarf disease

Rice black-streaked dwarf virus disease (RBSDV) may cause great loss of rice production, and breeding resistant varieties is an effective method to control RBSDV. To develop resistant varieties, it is important to screen germplasm that shows RBSDV resistance and to identify the genes/quantitative trait loci (QTLs) contained. In the present study, a set of 222 recombinant inbred lines (RILs) derived from the cross between L5494 (a susceptible japonica variety) and IR36 (a resistant indica variety) were constructed for RBSDV-resistant QTL mapping. With natural infection test, the RBSDV incidences of L5494 and IR36 were 84.26% and 28.70%, respectively, and the disease incidence of RILs was ranged from 11.21% to 89.81%. Using 134 polymorphic molecular markers, a linkage genetic map was constructed. The map covered a total length of 1475.97 cM with an average interval of 11. 1 cM between adjacent markers. Four RBSDV-resistant QTLs were discovered using QTL IciMapping 4.0 Software, of which, qRBSDV-1, qRBSDV-2, and qRBSDV-9 were from the resistant parent IR36, and qRBSDV-6 from the susceptible parent L5494. QTLs qRBSDV-1, qRBSDV-2, qRBSDV-6, and qRBSDV-9 were located on chromosomes 1, 2, 6, and 9, respectively, which explained 12.64%, 16.00%, 10.82%, and 8.43% of the phenotypic variations. Moreover, a RBSDV-resistant QTL from 93-11 (O. sativa spp. indica) at the qRBSDV-1 locus was confirmed by a near isogenic line that harbors qRBSDV-1 derived from 93-11 with the Nipponbare (O. sativa spp. japonica) genetic background. Our findings will be benefit for the marker assisted breeding of RBSDV-resistant varieties.