Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/30/2003
Publication Date: 10/1/2003
Citation: DELALIBERA, I., HAJEK, A.E., HUMBER, R.A. USE OF CELL CULTURE MEDIA FOR CULTIVATION OF THE MITE PATHOGENIC FUNGI NEOZYGITES TANAJOAE AND NEOZYGITES FLORIDANA. JOURNAL OF INVERTEBRATE PATHOLOGY. 2003. V. 84. P. 119-127. Interpretive Summary: This paper is one in a series about a major fungal pathogen affecting cassava green mite (CGM; a serious pest in South American and African cassava crops. This study shows that cultures of NEOZYGITES TANAJOAE (NT, the CGM pathogen) have significantly more restrictive nutritional requirements that do those of NEOZYGITES FLORIDANA (NF), a very similar mite pathogen that affects a much broader range of mites but not CGM. From among the 11 media tested, NT grew well successfully in only 3 media whereas NF grew well in 7 of the media. This study confirms the conclusion that NT and NF are distinct although nearly morphologically indistinguishable species, and provides significant information for successful culturing of NT and for the eventual development of this fungus as a biological control agent for use against CGM throughout the global range of this major cassava pest.
Technical Abstract: The pathogenic fungus NEOZYGITES TANAJOAE (NT), a highly efficient natural enemy of the cassava green mite (CGM) MONONYCHELLUS TANAJOA in Brazil, was released experimentally in Benin in 1998-99 to control CGM. Isolation methods and culture media for in vitro production of NT are reported. Continuous growth of NT was obtained with medium NT-1 (IPL-41 + 5-10% fetal bovine serum + 0.3% lactalbumin hydrolysate+0.3% yeastolate). This medium supported production of N. tanajoae up to 1.53 x 10exp7 hyphal bodies/mL after 8 days. The growth in 11 culture media of NT from Brazil was compared with 2 N. FLORIDANA (NF) isolates with wider host ranges from the US and Colombia. We showed these fungi have differing nutritional requirements. NT grows in few media and is highly specific for CGM while NF grows in serum-free media) and has a broader host range. NF isolates produced >2x10(6) hyphal bodies/mL in 7 of the 11 media tested. However the NT isolate achieved equivalent growth in only 3 media. Cell densities increased more slowly for NT in most media. The proposal that NT and NF are distinct species was at first based on host specificty, genetic and physiological patterns and is also supported by the results reported here.