ISOLATES OF POCHONIA CHLAMYDOSPORIA VAR. CHLAMYDOSPORIA FROM MEXICO AS POTENTIAL BIOLOGICAL CONTROL AGENTS OF NACOBBUS ABERRANS

Abstract

Perez-Rodriguez, I., A. Doroteo-Mendoza, F. Franco-Navarro, V. Santiago-Santiago and A. Montero-Pineda. 2007. Isolates of Pochonia chlamydosporia var. chlamydosporia from Mexico, as potential biological control agents of Nacobbus aberrans. Nematropica 37:127-134. Pathogenicity of five Mexican isolates of Pochonia chlamydosporia var. chlamydosporia to eggs of Nacobbus aberrans was tested. A standardized method for mass production of the fungus was established and the potential of isolates as control agents of the nematode in glasshouse production was evaluated. Three isolates (MPc1-MPc3) parasitized 77.2%-89.0% of eggs using potato agar plates as fungal inoculum, and 72.0%-87.0% using colonized rice as inoculum. In glasshouse production, tomato plants inoculated with 15,000 chlamydospores/g of soil of isolate MPc3 showed less damage and fewer nematodes in roots compared to untreated soil. Chlamydospores and colony forming units (CFU)/g of substrate colonized by MPc3 were greater after 15 days of liquid and solid fermentation in rice. Biphasic fermentation in cracked maize for 21 days allowed chlamydospore yields and numbers of CFU/g of substrate that were greater than those of the fermentation in rice, even if the percent germination of chlamydospores was less than that in rice. Chlamydospore concentration decreased in both substrates by prolonging the fermentation period to 28 days. In Mexico, cracked maize is a cheaper substrate than rice and potentially as effective as rice for mass production of the fungus. Results confirm the potential of this fungus as a biological control agent of N. aberrans.