QTL Mapping Of Leaf And Stripe Rust Resistance Genes In Wheat Varieties APAV And Ku3067

Wheat leaf rust and stripe rust have caused great harm to wheat production in China.Cultivation and planting of resistant cultivars are more friendly to the environment than chemical control.Cultivars with durable resistance can protect wheat from the harm of rust pathogen for a long time.Wheat cultivars APAV and Ku3067 are from the International Maize and Wheat Improvement Center and Afghanistan,respectively.In Mexico,the BC1F5 population from the cross of APAV/Ku067 was used for QTL analysis of leaf rust and stripe rust resistance,and the results showed that Ku3067 had good adult resistance to leaf rust and stripe rust,while APAV were susceptible.The resistance to wheat rust of the two parents were evaluated further in Hebei Agricultural University and the results showed that APAV had good rust resistance at seedling stage and adult stage,and Ku3067 had good resistance to leaf rust and stripe rust at adult stage.The aim of this study was to map leaf rust resistance genes in the BC1F5 population using resistance evaluation and molecular marker at seedling stage.At the same time,adult leaf rust resistance and stripe rust resistance were evaluated at Baoding in Hebei Province and Mianyang in Sichuan Province from 2019 to 2020 and 2020 to 2021,respectively.QTL analysis of adult leaf rust resistance and stripe rust resistance was further carried out using genotype data.The main results of this study are as follows:1.APAV was resistant to all Pt.rust races at seedling stage,indicating it has good resistance at seedling stage.Ku3067 was susceptible to all Pt.rust races at seedling stage,indicating that it did not contain effective resistance genes at seedling stage.Molecular marker detection showed that APAV contained Lr13 and Lr10,and known genes at seedling stage were not detected in Ku3067.2.A seedling rust resistance gene was mapped in APAV using molecular markers.This gene was identified as the known leaf rust resistance gene Lr13 by resistance analysis and functional marker analysis.3.Based on the evaluation data of leaf rust and strip rust resistance in adult stage combined with genotype data,three QTL were identified on chromosome 2A,4D and 7BL from Ku3067.respectively,which were QLr.hbau-2AL for leaf rust resistance,QLr/Yr.hbau-4DL for both leaf rust and stripe rust and QYr.hbau-7BL for strip rust resistance.QLr/Yr.hbau-4DL is a known pleiotropic adult plant resistance gene Lr67/Yr46 for leaf rust and stripe rust resistance.In addition,two loci were mapped in APAV,including QYr.hbau-4AL and QLr.hbau-2BS.QLr.hbau-2BS was the same locus as Lr13 identified at the seedling stage so the resistance of this locus was provided by Lr13.4.The field resistance of BC1F5 lines of APAV/Ku3067 was analyzed,and it was found that the lines with multiple loci had stronger resistance.Under the condition that the average FDS of leaf rust and stripe rust were both less than 5%,all the lines with different QTL combinations were screened,and 7 lines with high resistance to both rusts were obtained.Of all the QTL identified in this study,QYr.hbau-4DL was the same as that identified in Mexico,and the QTL identified in Mexico on 7BL and 2AL was similar to QYr.hbau-7BL and QLr.hbau-2AL in this study.Other three loci,including QLr.hbau-2BS and QYr.hbau-4AL identified in this study were only identified in this study.The resistance loci identified and the lines selected with higher resistance could provide theoretical basis and high quality resistance source for the genetic breeding of rust resistance in China.