Effect of foliar disease on the epiphytic yeast communities of creeping bentgrass and tall fescue

The effect of mechanical wounding or foliar diseases caused by Sclerotinia homoeocarpa or Rhizoctonia solani on the epiphytic yeast communities on creeping bentgrass and tall fescue were determined by leaf washing and dilution plating. Total yeast communities on healthy bentgrass and tall fescue lea...

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Bibliographic Details
Published in:Canadian Journal of Microbiology
Main Authors: Allen, Tom W, Quayyum, Habib A, Burpee, Leon L, Buck, James W
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2004
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Online Access:http://dx.doi.org/10.1139/w04-073
http://www.nrcresearchpress.com/doi/pdf/10.1139/w04-073
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Summary:The effect of mechanical wounding or foliar diseases caused by Sclerotinia homoeocarpa or Rhizoctonia solani on the epiphytic yeast communities on creeping bentgrass and tall fescue were determined by leaf washing and dilution plating. Total yeast communities on healthy bentgrass and tall fescue leaves ranged from 7.9 × 10 3 to 1.4 × 10 5 CFU·cm –2 and from 2.4 × 10 3 to 1.6 × 10 4 CFU·cm –2 , respectively. Mechanically wounded leaves (1 of 2 trials) and leaves with disease lesions (11 of 12 trials) supported significantly larger communities of phylloplane yeasts. Total yeast communities on S. homoeocarpa infected or R. solani infected bentgrass leaves were 3.6–10.2 times and 6.2–6.4 times larger, respectively, than the communities on healthy leaves. In general, healthy and diseased bentgrass leaves supported larger yeast communities than healthy or diseased tall fescue leaves. We categorized the majority of yeasts as white-pigmented species, including Cryptococcus laurentii, Cryptococcus flavus, Pseudozyma antarctica, Pseudozyma aphidis, and Pseudozyma parantarctica. The percentage of pink yeasts in the total yeast community ranged from 2.6% to 9.9% on healthy leaves and increased to 32.0%–44.7% on S. homoeocarpa infected leaves. Pink-pigmented yeasts included Rhodotorula glutinis, Rhodotorula mucilaginosa, Sakaguchia dacryoidea, and Sporidiobolus pararoseus. Foliar disease significantly affected community size and composition of epiphytic yeasts on bentgrass and tall fescue.Key words: dollar spot, phylloplane, Rhizoctonia blight.