Leaf rust resistance genes identification in the spring bread wheat breeding material of the Agricultural Research Institute for South-East Regions of Russia

Leaf rust caused by Puccinia triticina is a common bread wheat disease in the Volga Region of Russia and breeding for this disease resistance is a priority for the Agricultural Research Institute for South-East Regions wheat program. Knowledge of the effective resistance genes present in the germplasm is relevant when selecting for effective and more durable resistance. P. triticina races with virulence to Lr9, Lr19, Lr26 and with other different virulence combinations and molecular markers of L r genes were used to determine which seedling resistance genes might be present in the 68 bread wheat lines and cultivars. Studies have shown that the effective protection against leaf rust widespread in the Volga Region spring bread wheat cultivars is controlled by Lr6Ag and Lr6Agi+Lr19 genes. In addition, cultivars carry Lr10, Lr19, Lr10+Lr26 genes. It was found that in the studied set of lines the leaf rust resistance is determined by the following Lr-genes and its combinations: 9, 10, 19, 26, 34, 37, 41, Satu, 6Ag. Moreover, usage frequency of Lr19 is 89.5%, Lr10 -40.4%, Lr26 -31.6%, Lr6Ag -21%, Lr28 -3.5%, Lr41 -3.5%, Lr9 - 1.8%, Lr34 -1.8%, Lr37 -1.8%, LrSatu -1.8%. The frequency of two L r-genes combinations is 45.7%, three - 21% and four Lr-genes - 5.3%. Mainly are used such Lr-genes combinations as: Lr19+Lr26 and Lr10+Lr19+Lr26 - 22.8%; Lr19+Lr6Ag -7%. The four Lr-genes combinations has been included Lr10+Lr26+Lr28?+Lr6Ag -1.8%, Lr1+Lr10+Lr26+Lr6Ag -1.8% and Lr10+Lr19+Lr28?+Lr6Ag -1.8%. In addition, the effective Lr19 with nonidentified Lr-genes from cultivar Saratovskaya 57 (L164) and a. elongatum (CI-7-57) combinations has been identified.