Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2001
Publication Date: N/A
Technical Abstract: Eight strains of yeast ( M. pulcherrima), isolated from apples in an unmanaged orchard from 1993 to 1996 and selected for their biocontrol activity against blue mold of apples caused by P. expansum, were character- ized phenotypically, genetically, and compared for their biocontrol potential. All strains grew well in NYDB medium at 1 C, while at 0 C strain nT5-A2 grew much faster than other strains. This strain was also one of the most resistant to diphenylamine (DPA). BIOLOG test separated the strains into one major cluster containing four strains and four scattered strains. Strain ST1-D10 was the most distant from all the other strains. Genetic differentiation of the eight strains using maximum parsimony analysis of nucleotide sequences from domain D1/D2 of nuclear large subunit (26S) ribosomal DNA resulted in detection of two clades. Strain ST1-D10 grouped with the type strain of M. pulcherrima but the remaining seven strains grouped separately, suggesting a new species. All the strains reduced blue mold of apples but strain T5-A2 was distinctly more effective.