QTL Mapping For Adult-plant Resistance Gene To Leaf Rust In Sichuan Wheat Lines SW8588

Wheat leaf rust, caused by Puccinia triticina, is one of the most important and widespread diseases inChina. Continue screening, breeding, and planting the resistant cultivars are the most economical, safe andeffective method to control wheat leaf rust. Adult plant resistance is quantitative trait, and controlled bymultiple genes with durable resistance. Therefore it is very important to map adult plant resistance genesin Chinese lines for breeding wheat cultivars with durable resistance to leaf rust. SW8588was developedby Sichuan Academy of Agricultural Science and showed high resistance to leaf rust in the field.Former study showed that the SW8588carried Lr1, which has lost resistance to most of Pucciniatriticina pathotypes, but SW8588showed high resistance to mixture of the P. triticina pathotypes atadult stage in the field, indicating that SW8588might contain adult plant resistance genes. To map theadult plant resistance QTLs152F(2:3)lines were phenotyped for their leaf rust severities in the field2010-11and2011-12crop seasons, and1267SSR markers were screened between parents and smallresistant and susceptible groups, polymorphic markers were used to detect the152F(2:3)lines from thecross SW8588/Thatcher to construct genetic linkage maps. Phenotypic and genotypic data werecombined to map adult plant resistance QTLs in SW8588using software Mapmanager QTXb20andQTL IciMapping3.1.Three APR QTLs were identified in the F(2:3)population, located on2AS,7BL and1BL,respectively, all the QTLs were contributed by SW8588, and three QTLs explained13.94-17.04%,19.62-30.48%,15.69-31.03%of the phenotypic variation, respectively. The QTL on2AS was flankedby Xbarc1138-Xwmc177, Lr37was also located on the position, but Lr37was a major APR gene,therefore the QTL on2AS was different from Lr37. The QTL on7BL was flanked byXcfa2040-Xbarc182, located the terminal of7BL, and the QTL might be contributed by slow rustinggene Lr68, the effect of the QTL was stable during different environments. The QTL on1BL wasflanked by Xwmc728-Xgwm259, located on the terminal of1BL, and the QTL might be contributed byslow rusting gene Lr46. All the three QTLs had stable and signicant effect during two crop seasons,which explained the reason that SW8588showed high resistant to leaf rust in the field.