Articles
VEGETATIVE COMPATIBILITY IN POPULATIONS OF MONILINIA FRUCTICOLA FROM GEORGIA PEACH ORCHARDS
Article number
592_101
Pages
725 – 728
Language
English
Abstract
Monilinia fructicola, the fungus causing brown rot blossom blight and fruit rot of stone fruits, can overwinter in a sexual or asexual state in mummified fruit.
Due to climate and certain disease management practices, sexual reproduction is believed to be uncommon in Georgia peach orchards.
To evaluate genotypic variability of M. fructicola in the presumed absence of sexual reproduction, populations of the pathogen were characterized using vegetative compatibility groups (VCGs). Isolates were collected from blighted blossoms and infected fruit in two orchards in north and central Georgia.
Blossom blight isolates from the central Georgia orchard were genotypically very diverse (96.2% incompatibility). Only two of these isolates were compatible with any of the fruit rot isolates from the same group of trees, suggesting that the fungal populations responsible for the two phases of the disease are different.
Incompatibility among fruit rot isolates in the north and central Georgia populations was 23.0 and 42.0%, respectively.
In both populations, most VCGs were represented by a single isolate.
However, a single VCG representing a large percentage of the total number of fruit rot isolates occurred in a group of contiguous trees, suggesting short-distance spread among nearby trees from common sources of conidial inoculum.
Results of this study do not support the hypothesis of a strictly asexually reproducing population of M. fructicola in Georgia.
Due to climate and certain disease management practices, sexual reproduction is believed to be uncommon in Georgia peach orchards.
To evaluate genotypic variability of M. fructicola in the presumed absence of sexual reproduction, populations of the pathogen were characterized using vegetative compatibility groups (VCGs). Isolates were collected from blighted blossoms and infected fruit in two orchards in north and central Georgia.
Blossom blight isolates from the central Georgia orchard were genotypically very diverse (96.2% incompatibility). Only two of these isolates were compatible with any of the fruit rot isolates from the same group of trees, suggesting that the fungal populations responsible for the two phases of the disease are different.
Incompatibility among fruit rot isolates in the north and central Georgia populations was 23.0 and 42.0%, respectively.
In both populations, most VCGs were represented by a single isolate.
However, a single VCG representing a large percentage of the total number of fruit rot isolates occurred in a group of contiguous trees, suggesting short-distance spread among nearby trees from common sources of conidial inoculum.
Results of this study do not support the hypothesis of a strictly asexually reproducing population of M. fructicola in Georgia.
Publication
Authors
H. Scherm, K.M. Emery
Keywords
blossom blight, brown rot, genotypic variability, Prunus persica
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