Identification Of RGAP Markers Linked To Wheat Powdery Mildew Resistance Genes Pm6,Pm21 And Pm23

Abstract:In this study, we selected thirteen wheat lines carring different powdery mildew resistance genes, which had good resistance in wheat planting zone of henna province, and took the susceptible cultivar chancellor as the control, considering the results of resistance identification. According to the conserved sequence of resistance gene, seven pairs of RGA primers were designed for RGAP analysis.a special fragment C2 was amplified by the primer pair R11R/R11F in the Timgulan which carring Pm6 gene through screening the RGAP primers.It didn't appear in other lines tested. This fragment was cloned and sequenced,it was 1102bp. The homology analysis of DNA sequence showed, C2 had higher homology with known sequences in the genebank, such as the sequence of wheat leaf rust resistance gene Lrl0(AY270159.1), Triticum monococcum actin (ACT-1) gene RGA2 (A F326781.1) and Triticum aestivum NBS-LRR-like protein mRNA (AY084050.1). The analysis of inferred protein showed that its amino acid sequence include the analog sequence of resistance gene,an incomplete NB-ARC locus and two LRR sequences.The homology of conserved domain had 27.9% and 45.2% with known resistance protein sequences respectively.The 5' end of C2 were successfully extended to 852bp by Tail-PCR technique. The extended sequence became 1954bp.after analying the homology of the fragment, we found its nucleotide domains had higher homology than C2's which compared with known sequences in genebank ;The homology the conserved domains of amino acid arrived at 35.4% from the former 27.9%., The NB-ARC domain of extended sequence had 23 amino acid more than C2, and The extended amino acid sequence have higher homology with known resistance protein sequences. Such as AAW78913.1, AAK84082.1, AAQ01786.1, XP-4835601.1, BAA76281.2 and ABA 98920.1.Forecasting and analysis the jointed sequence 13-C2 by GENSCAN 1.0 TMpred, the results showed that 13-C2 had two exon one is initiation type, and the other is midst type, the forecasting peptide chain composed of 396 amino acid, and the cDNA length is 1188bp which have two or three helixes spanning velum.The primer pair R11R/R11F can amplify a special fragment C₃ in the Yangmai...