Nucleotide Diversity of Leaf Rusts Resistance Genes Lr29 and Lr47 Genomic Regions in Bread Wheat Lines (Triticum aestivum L.)

Leaf rust is one of the important wheat diseases which damages its production. Development of resistant varieties is an effective، environmentally friendly and low costly method for reducing disease damage. The aim of this study was to isolate and sequence Lr29 and Lr47 genes transferred to wheat from Agropyron elongatum and Triticum speltoides، respectively، in seven wheat lines with different levels of resistance to leaf rust. Using a specific primer pair، a fragment with length of 396 bp was isolated and sequenced from Lr47 gene in the studied lines having five open reading frames (ORF). The second ORF encoded a protein with length of 37 amino acids which showed 36% homology with wheat agglutinin antimicrobial protein. Alignment of the Lr47 sequence with NCBI data revealed 99% homology with Triticuma estivum sucrose synthase type I gene sequence. Nucleotide diversity of Lr47 gene was 0. 0041 and five single nucleotide polymorphism were identified among the seven lines. Bolani showed a large deletion with length of 48 nucleotide at 3’ non-coding end of the gene which could differentiate this line from the others. The length of isolated fragment from Lr29 gene was 160 bp which showed 91 and 90% similarity with acetyl CoA carboxylase gene from wheat and Aegilop stauschii، respectively. Twenty eight single nucleotide substitutions with nucleotide diversity of 0. 0589 were detected in Lr29 gene. Synonymous/non synonymous substitution ratio in Lr47 and Lr29 gene indicated negative and positive selection in the studied line for these genes، respectively.