Molecular Mapping Of Powdery Mildew Resistance Gene In Wheat-Thinopyrum Introgressions

Powdery mildew,caused by Blumeriagraminis f.sp.tritici,is a devastating disease in common wheat(Triticum aestivumL.)worldwide.To the day,more than 60 powdery mildew resistance genes have been identified on different chromosomes or arms.It is necessary to search and identify new genes for resentencing powdery mildew in wheat breeding.By using Wheat-Thinopyrum intermedium partial amphidiploid,we transfer excellent genes of Th.Intermedium into common wheat,then obtain a great diversity of variable types,Thinopyrum-derived wheat introgression lines CH7015.In this study,we used genetic analysis and molecular markers,determined the inheritance,chromosome location and linkage map to molecular markers of wheat introgression line CH7015.The main results in this work are summarized as follows:(1)Identifition at the seedling stage showed that the powdery mildew resistance gene of CH7015 was probably derived from Thinopyrum intermedium and TAI8335.(2)The results of adult stage showed that resistance gene in CH7015 is a pair of dominant nuclear gene,and tentatively designated as PmCH7015.(3)825 pairs of SSR primers were used to filtrate resistance gene for CH7015 and five codominant SSR markers(wmc657?gpw2328?wmc68?gpw4079 and gpw7272)were identified to be linked with PmCH7015 located on chromosomal arm 4BS of wheat according to bulked segregant analysis.(4)These markers orders and the genetic distances between the target gene and markers are wmc657-gpw2328-wmc68-PmCH7015-gpw4079-gpw7272 and 3.2 cM,1.3 cM,8.2 cM,1.4 cM and 15.1 cM,respectively.The markers of wmc68 and gpw4079 located on two sides PmCH7015,and the genetics linkage distance are 8.2 cM and 1.4 cM,respectively.In conclusion,PmCH7015 is a new powdery mildew resistance gene located the wheat chromosome arm 4BS,which derived from Thinopyrum intermedium.