V. Ivanova*, T. Alexandrov
Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria
(Manuscript received 19 March 2021; accepted for publication 15 September 2021)
Аbstract. The response of 1262 durum wheat lines to the cause agent of leaf rust Puccinia triticina was studied. The investigation was carried under infection field conditions during 2013-2015 at Dobrudzha Agricultural Institute (DAI) – General Toshevo, Bulgaria. Over the years of investigation, a maximum high infection background was developed by the cause agent of the disease, including all pathogen pathotypes identified during this period. The race variability in the population of the pathogen during the period was determined at the Plant Pathology Laboratory of DAI according to a validated methodology for working with rusts. Seventy-one phenotypically different virulent pathotypes were established. Fifteen new races of P. triticina were also identified, which have not been present during the previous 15 years in Bulgaria. Seventeen lines and one cultivar with a certain degree of resistance to the pathogen were selected. The selected lines can be involved in the breeding programs for developing initial material with resistance to leaf rust P. triticina.