YEAST POPULATIONS ON THE TROPICAL TIMBER TREE SPECIES MILICIA-EXCELSA

Yeast populations found on the tropical timber tree species Milicia ex celsa showed very little diversity at the genus and species level, Of 62 isolates, 87% were Cryptococcus laurentii, 5% Candida humicola, 3% Candida curvata, 1.5% Candida membranaefaciens, 1.5% Rhodotorula minut a and 1.5% Rhodotorula rubra. Approximately half of the Crypt. laurent ii strains had unusual metabolic profiles when compared with the Crypt . laurentii strains in the profile library of the APILAB yeast identif ication software. All isolated strains were non-pathogenic and did not show antagonism against Botrytis cinerea in an in vitro plate assay, However, three strains of Crypt. laurentii suppressed disease developm ent of B. cinerea in a leaf disk bio-assay, This indicates that protec tion of leaves against opportunistic fungal diseases may be part of th e ecological function of Crypt, laurentii populations on Milicia leave s and the potential of this yeast species for biological control.