Abstract:

Three different strains (numbered as 001#, 010# and 012#) of antagonistic yeast Crytococcus laurentii were investigated to understand their phylogenetic relationships and metabolic fingerprints in Biolog microbial identification system and biodefense efficacies against the main pathogens of fruits and vegetables. The results indicated that strains 001# and 010# had a close phylogenetic relationship and there were 43 optimal and 13 utilizable carbon sources in both of their carbon source metabolic fingerprints. However, strain 012# was quite different from strains 001# and 010# in carbon source utilization. The biodefense efficacies of these three strains against the mains pathogens in pear, nectarine and asparagus exhibited a quiet difference, which might be related to the utilization of different types of carbon source in different antagonistic strains and the type and amount of special carbon sources in fruits and vegetables. Meanwhile, the difference in biodefense efficacy could be induced by different types and amounts of carbon sources in fruits and vegetables, which reveals the relationship between metabolic characteristics and evolutionary distance of strains. These investigations provide a theoretical fundamental for studying biodenfense mechanisms of antagonistic strains.

Key words: Antagonistic yeast, Cluster analysis, Metabolic fingerprint, Biocontrol ability