Resumo

ESCALONA, Yoleidy; RODRIGUEZ, Dorian  e  HERNANDEZ, Alexander. Rhizoctonia solani Kühn isolated from potato in various Venezuelan states: II. Virulence and molecular characterization. Bioagro [online]. 2012, vol.24, n.1, pp.13-22. ISSN 1316-3361.

Rhizoctonia solani causes the disease known as rizoctoniosis in potato and it is a serious problem in Venezuela. Anastomosis groups and cultural characterization have been determined in the country, but neither molecular nor virulence characterization. Therefore, the research focused on those two objectives. Forty isolates from Táchira, Merida, Trujillo and Lara States were used on which RAPD, UPR and ITS techniques were performed; also, pathogenicity tests were run on ‘Kennebec’ potato plants. Genetic variability among isolates was observed with all three molecular techniques and presence of AG-3 and AG-2.1 was confirmed. Isolates showed significant difference with regard to virulence, which was influenced by temperature.

Palavras-chave : RAPD; ITS; UPR; rhizoctoniasis.