Quantitative Trait Loci Mapping Of Adult Plant To Stripe Rust In Wheat Cultivar Qinnong 142

Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is one of the most damaging diseases on wheat in the world.Four severe stripe rust prevalence have outbreak in China,resulting in great yield losses.The use of fungicide was not only environmental-unfriendly,also cost-ineffective.Growing resistant cultivars is considered the most effective,low-cost,and environmentally safe approach to control stripe rust.All-stage-resistance(ASR)cultivars have been widely deployed in wheat breeding programs in China since 1950.However,a great risk of growing cultivars with ASR often caused high selection pressure on the pathogen population,resulting in the emergence of new virulent races.however most of them conferace specific resistance that are no longer effective or likely to have short duration of effectiveness if widely deployed in cultivars.Therefore,it was necessary to explore new resistant varieties with durable resistance.The aim of this study was to map QTL of adult plant resistance to stripe rust in the common wheat cultivar Qinnong142 which show outstanding resistance in the field,and obtain the tightly linked markers which can be used in the marker assistant selection(MAS).In this study,four results were got:1.The resistance was investigated using seven Chinese prevalent isolates of Puccinia striiformis(CYR23?CYR29?CYR31?CYR32?CYR33?V26?SULL-7)at seeding stage in greenhouse.Additionally,the resistance was investigated at adult-plant stage in Yangling?Tianshui and Jiangyou in 2015 and 2016.The results showed Qinnong142 was susceptible to CYR32 and V26,but resistant to the remaining Puccinia striiformis;it also performed high level of resistance to stripe rust at the adult-plant stage in Yangling,Tianshui and Jiangyou.2.198 plants of F6 RIL population were identified adult plant response against stripe rust in five environments including in Yangling and Tianshui in 2015,in Yangling,Tianshui and Jiangyou in 2016,respectively.The infection type and disease severity(DS)were recorded.IT,MDS and rAUDPC distribution show that disease resistance were quantitatively inherited and could be stably genetic in F6 RIL population.The generalized heritability is 0.89 that could prove disease-resistant genetic stability in wheat cultivar Qinnong142.3.Construction a mapping population of the F6 RIL family with 198 plants which derived from the cross of AVS and Qinnong 142.The genetic linkage map was constructed with 35 K SNP array,this genetic linkage map include 5829 SNP and 64 SSR markers,the length of 4822.6cM,The average markers density of 0.84 cM/Marker.4.Three QTL conferring stable resistance were detected on 1BL and 2BL chromosome by QTL IciMapping 4.2.The detected QTL on 1BL was designated as QYr.qinnafu-1BL and flanked by SNP AX-94861924 and AX-94410152 which can explain 4.44%-20.41% of the phenotypic variance.The detected QTL on 2BL was designated as QYr.qinnafu-2BL.1 and flanked by SNP AX-9562871 and AX-94507002 which can explain8.29%-30.38% of the phenotypic variance;QYr.qinnafu-2BL.2 by SNP AX-94645171 and AX-95012510 which can explain4.27%-14.14% of the phenotypic variance.which indicate these QTLs can significantly reduce disease severity of stripe rust on wheat cultivar Qinnong 142.