玉米RFLP连锁图谱构建及大斑病QTL定位

Construction the RFLP Linkage Map and Location the NCBL QTL of Maize

玉米大斑病菌存在有生理小种分化的现象。目前 5个已定名的生理小种在我国均已发现 ,还有一些尚未定名的新类群也已出现。提高玉米对大斑病的抗性 ,只有提高数量抗性才能达到目的。为了弄清楚玉米对大斑病数量抗性的基因数目及效应 ,利用抗病自交系P138和感病自交系综 3为亲本构建了F2∶3 家系群体 ,采用RFLP标记构建了包含 12 4个标记的玉米RFLP连锁图 ,覆盖玉米基因组 1999 8cM ,标记间平均距离为 16 5cM。定位了玉米大斑病的病斑长、病斑宽和病斑面积的QTL分别为 3、3、2个 ,其联合贡献率分别为 5 8 1%、71 5 %和 2 7 5 %。没有检测到病斑数 /叶的QTL ,其表现为单基因或者寡基因控制的性状。研究结果增加了对玉米大斑病的认识 ,对玉米抗大斑病育种具有重要的指导意义。

There exists the race differential phenomenon in Exserohilum turcicum (namely NCBL). At present, there are 5 identified races of NCBL and some un known races in China. For improvement of maize resistance to NCBL, a basic method is to improve maize quantitative resistance. To identifiy the numbers and effects of the quantiative resistant loci to NCBL in maize, we constructed F 2∶3 population from resistant line P138 as male parent cross with sensitive line Z3 as female parent. Using RFLP marker technique, the RFLP linkage map of maize was cons cracted covering 1999.8cM, and the average distance between markers was 16.5cM . Identified QTL of NCBL lesion length, width, and area were 3, 3, 2, respectively. The combined contribution ratios of these QTL were 58.1%,71.5%,27.5%,respectively. No QTL was identified NCBL lesion number per leaf, it was a trait that might be controlled by one or oligo genes. Finglly, authors discussed and prospected the maize NCBL research in future.