Development of multiplex PCR to detect slow rust resistance genes Lr34 and Lr46 in wheat.

Leaf rust caused by Puccinia triticina belongs to one of the most dangerous fungal diseases of wheat (Triticum aestivum L.) and is the cause of large yield losses every year. Here we report a multiplex polymerase chain reaction (PCR) assay, which was developed for detection of two important wheat slow rust resistance genes Lr34 and Lr46, using two molecular markers: csLV34 and Xwmc44, respectively. The presence of genes was analyzed in one winter wheat variety TX89D6435 and five spring wheat varieties: Pavon F76, Parula 'S', Rayon 89, Kern, Mochis 88. Both Lr34 and Lr46 genes were identified in variety TX89D6435, gene Lr34 was also identified in Parula 'S' and Kern varieties, and gene L46 occurs in Pavon F76 and Mochis 88 variety. None of the resistance genes tested was detected in the Rayon 89 variety. The use of the multiplex PCR method allowed to shorten the analysis time, reduce costs of analyses, and reduce the workload.