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United States Department of Agriculture

Agricultural Research Service

Research Project: Mitigating Alternate Bearing of Pecan

Location: Fruit and Nut Research

Title: Characteristics of genetic variability among isolates of Fusicladium species from peach, almond and pecan in the USA

Authors
item Chen, Chunxian
item Bock, Clive
item Brannen, Phillip -
item Adaskaveg, James -
item Hotchkiss, Michael
item Brewer, Marin -
item Wood, Bruce

Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: May 9, 2011
Publication Date: N/A

Technical Abstract: Peach and almond scab, caused by Fusicladium carpophilum, and pecan scab, caused by F. effusum are serious diseases of their host crops, causing yield loss and downgrading of fruit. Genetic diversity of these pathogens has not previously been compared, but helps characterize pathogen variability and can aid with resistance breeding. The aim of this study was to use UP-PCR and RAPDs to compare variability within and among isolates from different hosts. A total of 18 isolates of F. carpophilum from peach (from the southeastern US), 12 from almond (from California), and 21 isolates of F. effusum (from the southeastern US) were screened against 9 RAPD and 5 UP-PCR markers. Combined marker results showed a low incidence of polymorphism among peach isolates (4.2% of markers), but a higher incidence of polymorphism among isolates from almond (42.0%) and isolates of F. effusum from pecan (61.0%). The Dice coefficient of similarity ranged from 0.9323 to 1.0000 for isolates of F. carpophilum from peach, 0.2143 to 0.9756 for almond isolates, and 0.5283 to 0.9200 for F. effusum. UPGMA bootstrap analysis (1000 runs) gave a high node value (100%) differentiating all isolates of F. carpophilum from F. effusum, and a moderate node value (68%) differentiating peach and almond isolates of F. carpophilum. The results suggest some divergence among isolates of F. carpophilum from almond in California and peach in the southeastern US.

Last Modified: 10/20/2014
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