Method of accelerated production of spore clones from single uredinia of sunflower rust pathogen using cytokinins

Under spreading of new biotypes of the sunflower rust pathogen in the regions of the Russian Federation, it became necessary to improve the previ-ously existing or develop new, more rapid methods for testing the resistance of breeding material. For this pur-pose, cytokinin-like preparations were tested in the im-munity laboratory of V.S. Pustovoit All-Russian Re-search Institute of Oil Crops: abscisic acid (ABA) of different concentrations; cytokinin paste; Bona Forte concentrate; Flora life; CRISTAFLOR®; Purshat-W; sodium benzoate; benzimidazole, for their ability to keep cut sunflower leaves and their fragments alive for a long time under regulated temperature and light re-gimes in order to quickly obtain urediniospore clones on them for inoculum preparation. Sunflower leaves and their fragments remained green for up to 20 days on abscisic acid and benzimidazole solutions, which allowed quick growth of the required number of clonal spores. On this basis, we developed a laboratory method of accelerated production of urediniospore clones on fragments of cut sunflower leaves placed in growth chambers with a substrate in the form of min-eral wool soaked in abscisic acid or benzimidazole so-lution, which, as we found, also contributed to the in-crease in the number of uredinia formed. On the 10th day of cultivation under controlled conditions, uredinia were formed on leaf fragments.