Identification of tomato root and crown pathogenic fungi in Marvdasht region, Iran

During the years 2009-2010, a survey was conducted in Marvdasht region (Fars province), to identify the casual agents of root and crown rot in tomato plants. Symptomatic and healthy looking samples collected from different fields were surface sterilized and cultured on potato dextrose agar. Eighty isolates belonging to 17 genera were separated from infected roots. Isolates of Pythium aphanidermatum, Phytophthora nicotiana, Rhizoctonia solani, Macrophomina phaseolina, Phoma betae and Fusarium oxysporum were able to cause root rot on tomato plants in pathogenicity tests. R. solani and P. nicotiana were most (26%) and least (2%) frequently isolated species, respectively. Pathogenicity tests on tomato plants also showed that R. solani and M. phaseolina were most severe pathogens. On tomato plants, this is the first report of M. phaseolina from Iran and P. nicotiana from Fars province.