Determination of pathotypes and physiologic races of Puccinia triticina, the causal agent of wheat leaf rust in Iran

 In order to identify the new races, determine the virulence/avirulence formula and distribution of the causal agent of the wheat, in the spring of 2018 and 2019, respectively, 21 and 40 samples of leaf rust-infected leaves were collected from wheat fields in Khuzestan, Lorestan and Ardabil Mazandaran, Golestan, Kermanshah, Ilam, Sistan, Baluchistan and Fars provinces. The reaction of the isolates were evaluated by inoculating them on 38 differential lines under controlled greenhouse conditions. The results of this study led to the identification of 20 pathotypes and 13 races in the first year and 28 pathotypes and 11 races in the second year. PKTTS (28%) and PKTTT (18%) were the most prevalent races. The results of this study showed that differential cultivars carrying Lr19 and Lr9 resistance genes were resistant to all isolates and no virulence was observed on them. Lr2a gene with resistance reaction to 17 isolates was the most effective gene for resistance to wheat leaf rust after the two above-mentioned genes. Also, differential lines carrying Lr29, Lr10/Lr27+/Lr31 and Lr2b genes with resistance reaction to the majority of the isolates in two years were the most effective genes for resistance to wheat brown rust after Lr9, Lr19 and Lr2a genes.