Transferring four yellow rust resistance genes to wheat cv. Kalhaydari using marker assisted backcrossing

Kalhaydari is a tall, drought tolerant and rain-fed cultivar which has been a dominant rain-fed cultivar in Fars and Kohgelouyeh and Boyerahmad provinces for a long time (more than 70 years). However, this superior cultivar is susceptible to yellow rust, caused by Puccinia striiformis f. sp. tritici. Yellow rust causes a severe damage to this cultivar in high rainfall years. The aim of the present study was to transfer two seedling resistance genes (Yr5 and Yr15) and two adult plant resistance genes (Yr18 and Yr29) from standard lines to this cultivar using marker assisted backcross. In four separate breeding projects, Kalhaydari was crossed with four donor parents including Yr5/6*Avocet'S', Yr15/6*Avocet'S', Lalbahadur/Pavon and Opata 85 to transfer Yr5, Yr15, Yr18 and Yr29 genes, respectively. The first generation (F1) was backcrossed with Kalhaydari (BC1F1). In the offspring, selection for desirable genotypes was performed using markers assisted selection. Then, offspring carrying the favorable genes were entered the second backcross. The third backcross was performed using the same method. After a few more backcrosses and a selfing generation four yellow rust-resistant lines with the same genetic background, Kalhaydari cultivar, will be created. Durable resistance can be achieved using genes pyramiding.