Archivio Journal of Plant Pathology

Abstract:

Two hundred twenty seven isolates of Rhizoctonia spp. were obtained from roots and hypocotyls of bean (Phaseolus vulgaris) grown in Erzurum, Turkey. Of these, 111 Rhizoctonia solani were identified as belonging to seven anastomosis groups (AG): AG-2-1 (0.9%), AG-3 (2.7%), AG-4 (47.8%), AG-5 (36.9%), AG-9 (8.1%), AG-10 (0.9%) and AG-11 (2.7%); 116 binucleate Rhizoctonia belonged to four anastomosis groups: AG-A (1.7%), AG-F (4.3%), AG-G (7.8%), and AG-K (86.2%). In vitro pathogenicity tests on bean cultivars showed that the highest disease severities were caused by AG-5 (B-1) and AG-4 (B-227) isolates, whereas AGG (B-16, B-3) and AG-F (B-5) isolates were weakly pathogenic. On the other hand, the other anastomosis groups of R. solani (AG-2-1, AG-3, AG-9, AG-10 and AG-11), and binucleate Rhizoctonia (AG-A, and AG-K) were not pathogenic on the five tested bean cultivars. ‘#eker’ was found to be the most resistant cultivar, and ‘Terzibaba’ was the most susceptible cultivar across all Rhizoctonia spp. tested. This is the first report of R. solani AG-2-1, AG-3, AG-9, AG-10, AG-11 and binucleate Rhizoctonia AG-F and AG-G on bean in Turkey.