شناسایی و تعیین پراکنش جدایه های مختلف Rhizoctonia در مزارع چغندرقند استان آذربایجان غربی

Sugar beet, along with sugarcane, is one of the two main crops grown for sugar extraction, and it is also one of the two most important sugar suppliers in the world. Various pathogens damage this product, which either act on the aerial parts of the plant or on the plant's roots. One of the most important pathogenic fungi is Rhizoctonia, which causes various diseases in sugar beet. During the growing season of 2023, 362 samples of sugar beet soil, roots and tubers were collected from different sugar beet fields in West Azarbaijan province. Cultivation and purification of different isolates were done. To ensure the correctness of the morphological studies, ITS region sequencing and phylogenetic tree drawing were performed and after this step, the genetic diversity of different isolates was investigated using ten ISSR primers. The results showed that isolates belong to AG-2-2 anastomose groups and the cities of Urmia and Mahabad had the highest level of pollution with an average of 33.33% and the lowest level of pollution was related to Khoi city with an average of 1.85%. Also, no contamination was observed in Qara Ziauddin city. The average total pollution in the province was 12.30%. ISSR marker was able to distinguish different populations of R. solani based on geographical regions. The P, H and I indices obtained from the data analysis indicated a high level of genetic diversity between the populations, and in general, this method was able to differentiate between the isolates obtained from different geographical areas. Also, Fst coefficient equal to 0.605 (p = 0.01) was obtained.