Abstract: Powdery mildew (Erysiphe graminis f. sp. tritici Em. Marchal.) and lodging cause great yield loss in wheat (Triticum aestivum L.) production. Adult-plant resistance (APR) is crucial in wheat breeding for permanent resistance to powdery mildew. Internode length below the spike (ILBS) is an important trait associated with lodging resistance (LDR) in wheat, however, the quantitative trait loci (QTLs) for ILBS have not been reported. In the present study, a set of 168 doubled haploid (DH) lines derived from the cross between Huapei 3 and Yumai 57 were used to detect QTLs associated with APR to powdery mildew, LDR, and ILBS with 305 SSR markers covering the whole wheat genome. The DH population and the parents were evaluated for APR to powdery mildew, LDR, and ILBS in 2005 and 2006 cropping seasons in Tai’an, Shandong province and in 2006 cropping season in Suzhou, Anhui province. QTL analyses were performed using the software of QTLNetwork version 2.0 based on the mixed linear model. A total of 12 additive QTLs and 10 pairs of epistatic QTLs were detected for APR to powdery mildew, LDR, and ILBS. One QTL qApr4D, donated by Yumai 57, was detected for APR to powdery mildew on chromosome 4D with increased resistance effect, accounting for 20.0% of the phenotypic variances without additive × environment (AE) interactions. Another QTL qIlbs7D for ILBS was identified on chromosome 7D, explaining 12.9% of the phenotypic variances without AE interactions. The results indicate both additive effects and epistatic effects are important genetic bases for APR to powdery mildew, LDR, and ILBS, which are also sometimes subjected to environmental modifications. The two QTLs, qApr4D and qIlbs7D, are useful for molecular marker–assisted selection in breeding for APR to powdery mildew and ILBS, respectively.

Key words: Wheat powdery mildew, Adult plant resistance, Internode length below the spike, Lodging resistance, Quantitative trait loci