Co-Authors:
Droby, S., Department of Postharvest Science, ARO, Volcani Center, Bet Dagan, 50250, Israel
Lischinski, S., Department of Postharvest Science, ARO, Volcani Center, Bet Dagan, 50250, Israel
Cohen, L., Department of Postharvest Science, ARO, Volcani Center, Bet Dagan, 50250, Israel
Weiss, B., Department of Postharvest Science, ARO, Volcani Center, Bet Dagan, 50250, Israel
Daus, A., Department of Postharvest Science, ARO, Volcani Center, Bet Dagan, 50250, Israel
Chand-Goyal, T., Environmental Protection Agency, 401 M Street SW, Washington, DC 20460, United States
Eckert, J.W., Department of Plant Pathology, University of California, Riverside, CA 92521, United States
Manulis, S., Department of Plant Pathology, ARO, Volcani Center, Bet Dagan, 50250, Israel
Abstract:
An epiphytic yeast population of grapefruit able to grow under high osmotic conditions and a wide range of temperatures was isolated and characterized for its biocontrol activity against green mold decay caused by Penicillium digitatum. Techniques based on random amplified polymorphic DNA (RAPD) and arbitrary primed polymerase chain reaction (ap-PCR), as well as homologies between sequences of the rDNA internal transcribed spacers (ITS) and 5.8S gene, were used to characterize the composition of the yeast population and to determine the genetic relationships among predominant yeast species. Epiphytic yeasts exhibiting the highest biocontrol activity against P. digitatum on grapefruit were identified as Candida guilliermondii, C. oleophila, C. sake, and Debaryomyces hansenii, while C. guilliermondii was the most predominant species. RAPD and ap-PCR analyses of the osmotolerant yeast population showed two different, major groups. The sequences of the ITS regions and the 5.8S gene of the yeast isolates, previously identified as belonging to different species, were found to be identical.