Genetic drag between a blast resistance gene and QTL conditioning yield trait detected in a recombinant inbred line population in rice

摘要

Using a recombinant inbred line (RIL) population of an indica cross Zhong 156/Gumei 2, two blast resistance genes were mapped (Zhuang et al. 1997, Zhuang et al. 1998, Wu et al. 1999;, Wu et al. 2000, Zheng et al. 2000). One gene is responsible for the leaf blast resistance and located on chromosome 12, and its resistance allele is derived from Zhong 156. The other gene is responsible for both leaf and neck blast resistances and located on chromosome 6, and its resistance allele is derived from Gumei 2. In this study, the same population was used to analyze the effect of the chromosomal segments harboring the blast resistance genes on yield traits. The genes on chromosome 6 and 12 were tentatively designated as Pi25(t) and Pi24(t), respectively. In1996 and 1998, nine plants of each of the 148 RILs were grown in the paddy field at China National Rice Research Institute, Hangzhou, China. The middle five plants were harvested at maturity. Grain yield per plant (GYD), number of panicles per plant (NP), number of filled grains per panicle (NFGP), total number of spikelets per panicle (TNSP), spikelet fertility (SF), 1000-grain weight (TGWT) and panicle length (PL) were measured. Mean values over two years were used for QTL analysis.