About rust pathogen on sunflower (review)

There is presented a review of literary sources devoted to studies of sunflower rust. Sunflower rust caused by an obligative parasite Puccinia helianthi Schwein. is again a limiting factor in the sunflower seed production. Such situation is caused by weather conditions and the development of new virulent patho-types of the pathogen. We identified 27 biotypes of P. helianthi Schwein., which infect sunflower in different regions of Russia. Such diversity of virulent biotypes can be connected with the intensive cultivation of sunflower hybrids of foreign breeding during last thirty years. From the literary sources, we know about four species of rust pathogen; theoretically, they can be introduced on sunflower fields of the Russian Federation. These species, even seldom, caused rust on cultivated and wild sunflower in different countries. Species P. enceliae and P. massalis are differed from P. helianthi on sunflower by morphological traits of teliospores. We did not find them on sunflower leaves infected by rust, that we collected in the different regions of the Russian Federation. P. xanthii, also known as burdock rust, is microcyclic and able to form only telia. P. canaliculata forms uredinia and telia only on the own alternative host – a hazel. During observations a life cycle of the rust pathogen in sunflower crops, we detected only specific morphological traits of teliospores and five-step development cycle, which fully corresponded to the description of P. helianthi, done by L.D. Schweinitz and added by his followers. Dominance of this species of the rust pathogen in sunflower crops in the Russian Federation certifies that only its virulent biotypes should be obligatory to use in sunflower breeding for immunity.