Abstract: 【】Wheat leaf rust, caused by Puccinia triticina, is a devastating disease that can cause severe yield loss. The use of resistant cultivars is the most economical and effective method to reduce damages caused by wheat leaf rust. Wheat line Lantian 9 is susceptible to most of the Chinese current leaf rust pathotypes at seedling stage, but showed high resistance at adult stage. The objectives of this study are to analyze the leaf rust resistance of Chinese wheat cultivar Lantian 9 in adult-plant and locate the QTL contained in Lantian 9 by using molecular markers, and to provide a theoretical basis for molecular breeding in wheat. 【Method】Total 197 F_2:3 lines derived from Lantian 9/Huixian Hong cross were used to map leaf rust QTL. The population was inoculated by three pathotypes, and then phenotyped for FDS in the field during 2011-2014 cropping seasons. A total of 1 232 SSR markers were used to detect resistant parent Lantian 9, susceptible parent Huixian Hong and F_2:3 lines, to get the genotypic data. Phenotypic and genotypic data were combined to map adult plant resistance QTL in Lantian 9 and Huixian Hong using QTL software Map Manager QTXb20 and Icimapping 3.2.【Result】Five QTLs were detected in the population. The QTL located on chromosome 2B was stalely identified in two cropping seasons, tentatively designated QLr.hbau-2BS, explained 6.0% and 9.1% of the phenotypic variations in two years, respectively. QLr.hbau-2BS was located in the marker interval Xbarc55-Xgwm148 and Xgwm429-Xwmc154. The logarithm of odds (LOD) threshold was 2.6 and 3.46. The additive effect was -6.1 and -8.7. The dominate effect was 3.03 and 3.4, respectively. The QTL located on chromosome 1B was stably identified in two cropping seasons, tentatively designated QLr.hbau-1BL.2, explained 7.7% and 10.7% of the phenotypic variations in two years, respectively. QLr.hbau-1BL.2 was located in the marker interval Xwmc766-Xbarc269. The LOD threshold was 2.5 and 3.1. The additive effect was -1.0 and -1.1. The dominate effect was -13.0 and -14.9, respectively. The other three QTLs were identified in only one cropping season, including one QTL on chromosome 1B, tentatively designated QLr.hbau-1BL.1 detected in 2011-2012 crop season; one on chromosome 4B, tentatively designated QLr.hbau-4BS detected in 2011-2012 crop season; one on chromosome 3A, tentatively designated QLr.hbau-3A detected in 2011-2012 crop season, explained 11.7%, 8.5% and 5.6% of the phenotypic variation, respectively. These three QTLs were located in the marker interval Xbarc80-Xwmc728, Xgwm495-Xwmc652 and Xgwm161-Xbarc86. The LOD threshold was 5.1, 4.0 and 2.8. The additive effect was 6.5, -5.5 and -3.1. The dominate effect was -6.5, 6.2 and 6.6, respectively. QLr.hbau-1BL.1 comes from Huixian Hong, the other four QTLs come from Lantian 9. 【Conclusion】Combining with the phenotype and genotype data, detected five leaf rust resistance QTLs on chromosomes 1B, 2B, 3A, and 4B, respectively.

Key words: wheat (Triticum aestivum L.), leaf rust, adult-plant resistance gene, genetic analysis, QTL molecular mapping