QTL Mapping For Restorer Gene In Dongxiang Wild Rice (Oryza Rufipogon Griff.)

It is very important to research the fertility restorer genes ( Rf ) for cytoplasmic male sterility (CMS) in wild rice for our better understanding the origin of the Rf , the interaction between cytoplasm and nuclear , and the development of new restorer lines.To study restorer genes in Dongxiang Wild Rice(Oryza rufipogon Griff.), we developed a set of backcrossing inbred line (BIL) population consisting of 239 individuals (XieqingzaoB//XieqingzaoB/Dongxiang wild rice) for genetic linkage map construction. QTL mapping for fertility restoration was undertaken by using two test-cross populations of XieqingzaoA/(XieqingzaoB//XieqingzaoB/Dongxiang wild rice)BC1F10 and Zhong 9 A/(XieqingzaoB//XieqingzaoB/ Dongxiangwild rice)BC1F10. The results are summarized as follows.1. Inheritance of the fertility restoration for cytoplamic male sterility (CMS) in Dongxiang Wild Rice (DXWR) was studied using two test-cross populations"Xieqingzao A/(Xieqingzao B// Xieqingzao B/DXWR) BC1F10"and"Zhong9 A/(Xieqingzao B// Xieqingzao B / DXWR) BC1F10". The results showed that the spikelet fertility of DXWR to CMS-DA and CMS-IA behaved as qualitative-quantitati -ve trait, and the fertility restoration was controlled by major genes and affected by minor genes.2. A linkage map consisting of 130 SSR markers was constructed. it covered all the 12 chromosomes of rice and spanned for 1530.8cM with a average distance of 11.8cM between markes.3. Putative QTLs for fertility restoration were detected by composite interval mapping(CIM) of WinQTLCartographer version 2.5. Only the QTL detected with a minimum LOD score of 2.5 were determined on the linkage map. In the test-cross population of XieqingzaoA/(XieqingzaoB//XieqingzaoB/DongxiangWild rice) BC1F10, one QTL for fertility restotation was detected in the interval RM304-RM171 on chromosome 10. This QTL contributed 10.0% of phenotypic variation. In the test-cross population of Zhong 9A/(XieqingzaoB//XieqingzaoB/Dongxiang wild rice) BC1F10, five QTLs for fertility restotation was detected . One QTL that contributed 8.2% of phenotypic variation was detected in the interval RM10116-RM10176 on chromosome 1. Two QTLs that contributed 12.5% and 6.5% of phenotypic variation respectively were detected in the interval RM289-RM249 and RM3870-RM274 on chromosome 5. Two QTLs that contributed 4.8% and 5.5% of phenotypic variation respectively were detected in the interval RM1375-RM5620 and RM304-RM171 on chromosome 10.4. To comparison QTLs detected in the two population, the QTL in the interval RM304-RM171 on chromosome 10 was detected in both populations. However, the other QTLs detected in the population of Zhong 9A/(XieqingzaoB//XieqingzaoB/Don gxiang wild rice) BC1F10 were not detected in the population of XieqingzaoA/Xieqing zaoB//XieqingzaoB/Dongxiang wild rice) BC1F10. These results showed that Dongxiang Wild Rice had restoring QTLs for rice fertility restoration, however, the number of restoring QTLs and the fertility restoration ability might vary from one to another.