Detection and verification of quantitative trait loci for resistance to Fusarium ear rot in maize
Detection and verification of quantitative trait loci for resistance to Fusarium ear rot in maize
复制标题
DOI：
10.1007/s11032-012-9748-1
复制
发表时间：
2012-12-01
影响因子：
3.1
通讯作者：
Wu, Jianyu
中科院分区：
文献类型：
--
作者：
Chen, Jiafa;Ding, Junqiang;Wu, Jianyu
由轮枝镰刀菌（Fusarium verticillioides）引起的玉米穗腐病是玉米上的一种重要病害，严重影响玉米产量和品质。鉴定穗腐病抗性的稳定数量性状位点（QTL）是了解穗腐病抗性遗传机制和利用分子标记辅助选择的基本前提。本研究利用抗病自交系BT-1与感病自交系Xi 502杂交构建的210个F（2：3）家系，利用178个简单重复序列标记进行了基因型分析。通过人工接种，使用钉穿孔法在两种环境中评估每个品系的抗性。利用复合区间作图法检测抗病QTL。在第4、5和10染色体上检测到3个QTL。其中，位于第4染色体上的QTL（bin 4.05/06）对穗腐病的抗性最大，可解释17.95%的表型变异。为了进一步验证QTL效应，我们以亲本系Xi 502为轮回亲本，培育了携带第4染色体上QTL区域的近等基因系（NILs）。在近等基因系背景下，如果抗性区为纯合，该QTL可使抗性提高33.7- 35.2%，如果抗性区含有杂合等位基因，该QTL可使抗性提高17.8- 26.5%。该QTL在第4染色体上的稳定和显著的抗性效应为进一步进行玉米分子标记辅助选择和图位克隆奠定了基础。
Fusarium ear rot caused by Fusarium verticillioides is a prevalent disease in maize which can severely reduce grain yields and quality. Identification of stable quantitative trait loci (QTL) for resistance to Fusarium ear rot is a basic prerequisite for understanding the genetic mechanism of resistance and for the use of marker-assisted selection. In this study, two hundred and ten F (2:3) families were developed from a cross between resistant inbred line BT-1 and susceptible inbred line Xi502, and were genotyped with 178 simple sequence repeat markers. The resistance of each line was evaluated in two environments by artificial inoculation using the nail-punch method. The resistance QTL were detected using the composite interval mapping method. Three QTL were detected on chromosomes 4, 5 and 10. Of them, the QTL on chromosome 4 (bin 4.05/06) had the largest resistance to Fusarium ear rot, and could explain 17.95 % of the phenotypic variation. For further verification of the QTL effect, we developed near-isogenic lines (NILs) carrying the QTL region on chromosome 4 using parental line Xi502 as the recurrent parent. In the NIL background, this QTL can increase the resistance by 33.7-35.2 % if the resistance region is homozygous, and by 17.8-26.5 % if the resistance region contains the heterozygous allele. The stable and significant resistance effect of the QTL on chromosome 4 lays the foundation for further marker-assisted selection and map-based cloning in maize.