DisplayTitle

Molecular and Physiological Analysis of the Powdery Mildew Antagonist Pseudozyma flocculosa and Related Fungi

First, second, and fifth authors: Département de Phytologie, Université Laval, Québec (Qc), Canada, G1K 7P4; third author: Centraalbureau voor Schimmelcultures, Yeast Division, Julianalaan 67, 2628 BC Delft, the Netherlands; and fourth author: Natural Resources Canada, Centre de Foresterie des Laurentides, 1055 rue du PEPS, P.O. Box 3800, Sainte-Foy (Qc), Canada

A number of phenotypic and genotypic characteristics were used to ascertain the identity and diversity of Pseudozyma flocculosa, a natural antagonist of powdery mildews that has received little attention in terms of taxonomy. To this end, several putative isolates of P. flocculosa as well as several closely related species were analyzed. Ribosomal DNA sequences distinguished P. flocculosa from other Pseudozyma spp. and identified two previously unknown Pseudozyma isolates as P. flocculosa. Random amplified microsatellites revealed three distinct P. flocculosa strains among the tested isolates. Biocontrol properties and antifungal metabolite production were limited to the P. flocculosa spp. Results produced useful molecular markers to (i) distinguish P. flocculosa from other related fungi, (ii) identify different strains within this species, and (iii) aid in the construction of isolate-specific molecular tools that will assist in research and development of P. flocculosa as a biocontrol agent of powdery mildew fungi.

Additional keywords: antifungal fatty acids .