CIMMYT小麦品种Saar的叶锈成株抗性QTL分析

 【目的】小麦品种Saar由CIMMYT育成，在欧洲、亚洲和南美洲对小麦叶锈、条锈和白粉病均表现出很高的成株抗性，发掘其成株抗叶锈QTL对于选育持久抗锈品种有重要作用。【方法】以Avocet与Saar杂交的109个F6代重组自交系为材料，利用142个SSR标记和209 DArT（Diversity Arrays Technology）标记构建连锁图，对Saar和Avocet的成株抗性进行QTL分析。试验材料于2006－2007年度种植在河北保定和河南新乡两个试验点，调查各个家系对叶锈病的成株抗性。【结果】由351个位点组成的遗传连锁图，覆盖小麦21个连锁群，全长3 083 cM。采用复合区间作图法进行叶锈成株抗性的QTL分析，在1BL、2DS、5BL、6AL和7DS染色体上发现了5个抗叶锈病QTL，分别解释4.5%～6.4%、12.2%～12.5%、4.9%～11.2%、4.9%～7.8%和14.0%～67.6%的表型变异。【结论】叶锈成株抗性基因及其紧密连锁分子标记的发掘，将为小麦抗叶锈病育种的分子标记辅助选择（MAS）提供理论和技术支持。

QTL Mapping for Adult-Plant Resistance to Leaf Rust in CIMMYT Wheat Cultivar Saar

【Objective】 The CIMMYT wheat cultivar Saar has exhibited a high level of adult-plant resistance to leaf rust, stripe rust and powdery mildew in Europe, Asia, and South America, and identification of its QTL for leaf rust resistance will play an important role in breeding wheat cultivars for durable resistance. 【Method】 A total of 142 SSR and 209 DArT markers were used to map QTL for resistance to leaf rust in a recombinant inbred line (RIL) population with 109 F6 families derived from the cross Avocet/Saar. The field trials were conducted in Baoding, Hebei province and Xinxiang, Henan province in 2006－2007 cropping season. 【Result】 Linkage analysis indicated that the genetic map consisting of 142 SSR markers and 209 DArT markers covered 21 wheat linkage group with a total genetic distance of 3083 cM. Using composite interval mapping (CIM), five QTLs for resistance to leaf rust were detected on chromosomes 1BL, 2DS, 5BL, 6AL and 7DS, explaining 4.5%-6.4%, 12.2%-12.5%, 4.9%-11.2%, 4.9%-7.8%, and 14.0%-67.6% of phenotypic variance, respectively. 【Conclusion】 The QTLs and their closely linked molecular markers identified in this study will benefit to marker-assisted selections and wheat germplasm enhancement in breeding wheat cultivars for leaf rust resistance.