玉米抗灰斑病QTL元分析及其验证

Meta-analysis and Validation of QTL for Resistance to Gray Leaf Spot in Maize

玉米灰斑病是危害玉米生产的主要病害之一,目前对抗灰斑病基因数目、位置及作用方式仍然不清楚,这严重制约着玉米抗灰斑病育种进展。本研究利用元分析方法分析并整理了14篇玉米抗灰斑病QTL文献的信息,共筛选确定了13个一致性QTL区间。利用以自交系81162为轮回亲本、自交系CN165为非轮回亲本构建的回交导入群体根据连锁不平衡原理对13个一致性QTL进行验证,在13个一致性QTL区间共获得20多个偏分离位点。第1和第4染色体上偏分离最严重,其他染色体上偏分离度较小。说明第1和第4染色体上存在着效应较大的抗病QTL。第1染色体标记umc2227、bnlg1832、umc1243、umc2025、umc1515、umc1297、umc1461处供体基因频率均在50%以上,可能存在几个连锁的抗病基因。第4染色体上基因位于标记bnlg2291和umc1194之间。研究为精细定位供体CN165中第1和第4染色体上的抗灰斑病QTL奠定了基础。

Gray leaf spot（GLS） is one of the most severe leaf diseases of maize worldwide. The breeding progress for resistance to GLS has been seriously hindered by less knowledge about QTL number, QTL intervals and mechanism of GLS. Based on meta-analysis, we conformed 13 consensus QTL regions from 14 articles on resistance to gray leaf spot of maize. One backcross with inbred line 81162 as recurrent parent and inbred line CN165 as donor parent, was used to test the consensus of those 13 QTL regions on the basic of linkage disequilibrium getting more than 20 partial separated loci. High level of partial separation indicated that there were QTLs with high effects of resistance to GLS on chromosome 1 and chromosome 4. On chromosome 1, the donor genes closed to markers of umc2227, bnlg1832, umc1243, umc2025, umc1515, umc1297, and umc1461 showed the frequency over 50%. Therefore, we inferred that there were a few of highly linked QTLs on chromosome 1. The resistant QTL on chromosome 4 was located between markers bnlg2291 and umc1194. Consequently, this study could lay a foundation for the QTL fine mapping on chromosome 1 and chromosome 4 in the donor parent CN165.