Abstract:

【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.

Key words: common wheat (Triticum aestivum L.), leaf rust, adult-plant resistance, QTL mapping