Genetic resistance is the most economical method of reducing yield losses caused by wheat leaf rust. To identify the leaf rust resistance genes in commonly used parental germplasm and released cultivars become very important for utilizing the genetic resistance to wheat leaf rust fully. Up to date, about 90 leaf rust resistance genes have been found, of which 51 genes have been located and mapped to special chromosomes, and 56 genes have been designated officially according to the standards set forth in the Catalogue of Gene Symbols for wheat. Twenty-four wheat leaf rust resistance genes have been developed for their molecular markers. It is very important to isolate, characterize, and map leaf rust resistance genes due to the resistance losses of the genes caused by the pathogen continuously.
The differential genes expression of adult plant resistance gene of TcLr35 was analysed by using cDNA-AFLP technique.The results showed that 33 of 843 amplified bands were differential ones in different growth stages of TcLr35.A polymorphic band amplified by primer pair E-TG/M-CTG was found at different leaf-growing stages from the second to the sixth leaf of TcLr35 and absent in Thatcher and the seedling stage of TcLr35 on TcLr35 without inoculated with Puccinia recondita.Reverse Northern blotting test suggested that band E-TG/M-CTG-192 was a piece of special gene fragment of TcLr35.The band was cloned and sequenced subsequently.The fragment of 192 bp produced by E-TG/M-CTG contained an open reading frame(ORF),but did not show homologous to the published wheat gene sequences.
