In China,Xinjiang is a relatively independent epidemic region of wheat stripe rust,caused by Puccinia striiformis f.sp.tritici,due to great population genetic divergence of Xinjiang with other inland epidemic regions....In China,Xinjiang is a relatively independent epidemic region of wheat stripe rust,caused by Puccinia striiformis f.sp.tritici,due to great population genetic divergence of Xinjiang with other inland epidemic regions.In this region,race evolution was usually slower than inland populations.However,many new races have recently been found,and therefore,it is necessary for more understanding of the virulence evolution of the Xinjiang population.So,in this study,a 65 sexual progenies,derived from a Xinjiang single-urediospore isolate BGTB-1 of P.striiformis f.sp.tritici by selfing on alternate host barberry(Berberis aggregata).It was phenotyped on the 25 single Yr lines,and genotyped by 19 kompetitive allele-specific PCRsingle nucleotide polymorphism(KASP-SNP) markers.As a result,the 65 progenies were identified as 56 various virulence patterns(VPs),and neither of which was identical to the parental isolate,showed 100% virulence variation.Compared with the parental isolate,of all progenies,39(60.0%) had increased virulence,and 18(27.7%) had decreased virulence.All progenies exhibited avirulence to Yr10,Yr15,Yr32,and YrTr1 loci,and avirulence and virulence segregation at the remaining 21 Yr resistance loci.The results showed avirulence to Yr5,Yr7,and Yr76(A:V≈3:1) loci is controlled by a single dominant gene,and that to Yr6,Yr25,and Yr44(A:V≈1:3) loci by a single recessive gene.However,avirulence to the remaining 15 resistant loci including Yr1,Yr2,Yr3,Yr4,Yr8,Yr9,Yr17,Yr26(=Yr24),Yr28,Yr29,Yr43,YrSP,Yr27,YrA,and YrExp2,with various avirulence and virulence segregation ratios,is controlled by two genes with different gene effects,indicating complex genetic traits of the parental isolate.Totally,65 dissimilar genotypes detected among progenies using overall molecular markers,by which a linkage map was constructed,with a genetic distance of 441.0 cM.Interestingly,although the parental isolate was avirulent to Yr5,but 17 progenies showed virulence,showing the change of pathogenicity from avirulence to virulence at this resistance locus.It was for the first time to report that progenies with virulence to Yr5 produced sexually from avirulent parental isolate at this resistance locus.To our knowledge,this study offers an insight into inheritance,sexual reproduction and virulence variation of P.striiformis f.sp.tritici in Xinjiang,facilitating us to understand evolution of the rust pathogen in this region and accounting for Xinjiang population distinguished form other inland populations.Additionally,it is necessary to further confirm the roles of sexual reproduction in the emergence of new races and affecting population genetic diversity of P.striiformis f.sp.tritici under natural conditions in Xinjiang.展开更多
基金financially supported by Xinjiang Major Science and Technology Projects,China (2023A02009)。
文摘In China,Xinjiang is a relatively independent epidemic region of wheat stripe rust,caused by Puccinia striiformis f.sp.tritici,due to great population genetic divergence of Xinjiang with other inland epidemic regions.In this region,race evolution was usually slower than inland populations.However,many new races have recently been found,and therefore,it is necessary for more understanding of the virulence evolution of the Xinjiang population.So,in this study,a 65 sexual progenies,derived from a Xinjiang single-urediospore isolate BGTB-1 of P.striiformis f.sp.tritici by selfing on alternate host barberry(Berberis aggregata).It was phenotyped on the 25 single Yr lines,and genotyped by 19 kompetitive allele-specific PCRsingle nucleotide polymorphism(KASP-SNP) markers.As a result,the 65 progenies were identified as 56 various virulence patterns(VPs),and neither of which was identical to the parental isolate,showed 100% virulence variation.Compared with the parental isolate,of all progenies,39(60.0%) had increased virulence,and 18(27.7%) had decreased virulence.All progenies exhibited avirulence to Yr10,Yr15,Yr32,and YrTr1 loci,and avirulence and virulence segregation at the remaining 21 Yr resistance loci.The results showed avirulence to Yr5,Yr7,and Yr76(A:V≈3:1) loci is controlled by a single dominant gene,and that to Yr6,Yr25,and Yr44(A:V≈1:3) loci by a single recessive gene.However,avirulence to the remaining 15 resistant loci including Yr1,Yr2,Yr3,Yr4,Yr8,Yr9,Yr17,Yr26(=Yr24),Yr28,Yr29,Yr43,YrSP,Yr27,YrA,and YrExp2,with various avirulence and virulence segregation ratios,is controlled by two genes with different gene effects,indicating complex genetic traits of the parental isolate.Totally,65 dissimilar genotypes detected among progenies using overall molecular markers,by which a linkage map was constructed,with a genetic distance of 441.0 cM.Interestingly,although the parental isolate was avirulent to Yr5,but 17 progenies showed virulence,showing the change of pathogenicity from avirulence to virulence at this resistance locus.It was for the first time to report that progenies with virulence to Yr5 produced sexually from avirulent parental isolate at this resistance locus.To our knowledge,this study offers an insight into inheritance,sexual reproduction and virulence variation of P.striiformis f.sp.tritici in Xinjiang,facilitating us to understand evolution of the rust pathogen in this region and accounting for Xinjiang population distinguished form other inland populations.Additionally,it is necessary to further confirm the roles of sexual reproduction in the emergence of new races and affecting population genetic diversity of P.striiformis f.sp.tritici under natural conditions in Xinjiang.
