Identification of the powdery mildew caused by Erysiphe cruciferarum on Brassica napus in Russia

• Main Authors: Mikhaylova, Elena, Shein, Michael, Alexeev, Valentin, Sukhareva, Anna, Panfilova, Maria
• Format: Conference Proceeding
• Language: English
• Subjects: Brassica; Fungal diseases; Fungi; Genetic engineering; Oilseed crops; Oilseeds; Pathogens; Plant resistance; Rape plants; Rapeseed; Sonchus; Weed control
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0068529

Powdery mildew is one of the least studied plant fungal diseases. It is caused by obligate fungal parasites of Erysiphaceae family. These pathogens cannot be cultured on nutrient medium, therefore mechanisms of plant protection against them are hard to investigate. For example, in Russia, the varieties of oilseed rape resistant to powdery mildew have never been selected. It is supposed that plant residues, as well as perennials Convolvulus arvensis and Sonchus sp., can be reservoirs of infection. Here we demonstrate that powdery mildew samples collected from oilseed rape and its weed convolvulus are host specific and it is unlikely that the pathogen can transfer to agricultural crop from unrelated weeds. The sequences of internal transcribed spacers (ITS1 and ITS2) of powdery mildew isolated from these two plants clearly belong to different species Erysiphe convolvuli and E. crucifertaum. They show high similarity to the sequences of the same species from all over the world. However, lack of weed control results in a decrease in plant immunity and promotes favorable environment for the disease. Genetic engineering and genome editing of PR1, PMR6, GST and other target genes can be used to increase plant resistance to powdery mildew.