Rhizoctonia Species, Anastomosis Groups, and Pathogenicity Isolated From Common Bean in Lake Van Basin, Turkiye

Abstract

Common bean (Phaseolus vulgaris L.) is an important vegetable crop grown in Lake Van Basin. Local genotypes are widely grown in the region. Rhizoctonia root rot induced by Rhizoctonia solani Kühn is an important soilborne plant disease that leads to global economic losses as well as in Turkey. The present study was conducted to determine anastomosis groups and pathogenicity of Rhizoctonia spp. obtained from bean plants in Lake Van Basin in 2013 and 2014. A total of 236 Rhizoctonia isolates in 5 anastomosis groups were obtained from bean plant roots. It was observed that AG- 4 (112) was the most isolated group in beans, followed by AG- 2 (41), AG- 3 (28), AG- 5 (33), and binucleate AG- K (22) isolates. Pathogenicity test conducted in thirty isolates in 5 anastomosis groups was analyzed for A64 (Bitlis/ Adilcevaz), TR68557 genotypes, and Gina (cv.) under growth chamber conditions. The study findings demonstrated that all tested isolates could infect the bean plant with different degrees of severity; however, the most virulent group was AG- 4. It was determined that the most virulent isolate was Isolate No. 19 in the A64 genotype, Isolate No. 2 in TR68557, and Isolate No. 18 in Gina cv. in in vivo tests. The identification and pathogenicity determination of Rhizoctonia isolates are the first steps towards an efficient control strategy for bean diseases caused by Rhizoctonia species. In order to obtain quality and productive products in the Van Lake Basin, where intensive bean production is carried out, precautions should be taken by considering the damage caused by Rhizoctonia spp. on plants.