Abstract
Common bean rust, caused by basidiomycete fungus Uromyces appendiculatus is a major concern for common bean production worldwide. It occurs sporadically in the plains of Bulgaria but for the The Rhodopе Mountains it is of economic importance and appear annually. The use of resistant cultivars is the most cost-effective strategy to manage bean rust disease. The aim of the present study is to screen common bean lines to several pathotypes of U. appendiculatus to find a source of resistance. The investigation was carried out during 2023 at the Laboratory Complex of the Dobrudzha agricultural institute, General Toshevo. Twelve breeding lines of common bean were inoculated with eight pathotypes of races 20-2,20-16 and 20-18. The reaction of lines was recorded 14 to 15 days after inoculation as infection type (IT) using six-point scale. The results showed that lines can be divided into three groups. The first group includes four of the P. vulgaris lines (DG 17-38-16; DG 17-38-38; DG 17-38-77; DG 17-38-9) which were immune, hypersensitive or resistant to all used U. appendiculatus pathotypes. The second group consists of three lines (DG 17-38-27, DG 17-38-28, and DG 17-38-46) which showed sensitive phenotype to all used pathotypes. Тhe third group includes five lines with a mixed type of reaction to the studied pathotypes. The lines from the first group can be successfully used as a donor parent in a breeading program for developing common bean cultivars resistant to U. appendiculatus.