Temporal shifts in genetic structure and differentiation of Cercospora beticola populations in table beet fields of New York

Knight, Noel L. and Vaghefi, Niloofar and Hansen, Zachariah R. and Kikkert, Julie R. and Pethybridge, Sarah J. (2017) Temporal shifts in genetic structure and differentiation of Cercospora beticola populations in table beet fields of New York. In: 2017 Annual Meeting of the Northeastern Division of the American Phytopathological Society, 1-3 Nov 2017, Quebec City, Canada.


Cercospora leaf spot (CLS), caused by Cercospora beticola, is an important fungal foliar disease of table beet (Beta vulgaris ssp. vulgaris). In broad-acre table beet production CLS may cause defoliation, which prevents mechanized harvesting and leads to substantial crop loss. Previous studies have characterized high allelic and genotypic diversity within C. beticola populations in table beet fields in New York, which may be suggestive of an active sexual morph. Rapid evolution of resistance to fungicides as a function of this diversity threatens the durability of the dominant control tactic for this disease. This study quantifies temporal changes in genetic structure and differentiation of C. beticola populations from three locations in New York, using 12 microsatellite markers. High allelic (Nei’s index of gene diversity (He) = 0.34 to 0.61) and genotypic diversity (Simpson’s complement index (λ) = 0.75 to 0.97) was present in each population. Indices of differentiation between years varied, with pairwise index of differentiation (φPT) values ranging from 0.02 to 0.25 for clone-corrected data, indicating significant genetic differentiation in some locations. No multilocus genotype was shared between years or locations. Hypotheses to explain significant temporal shifts in genetic diversity and population differentiation are being investigated. The diversity and variation in C. beticola populations reveals the potential for rapid genetic changes, including an increased risk of fungicide resistance development. This information highlights the importance of adhering to best management guidelines for fungicides in conventional table beet production.

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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Speech)
Refereed: Yes
Item Status: Live Archive
Additional Information: Abstracts only published from Conference.
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Crop Health
Date Deposited: 23 Apr 2019 23:26
Last Modified: 24 Jun 2019 03:13
Fields of Research : 06 Biological Sciences > 0607 Plant Biology > 060704 Plant Pathology
06 Biological Sciences > 0604 Genetics > 060411 Population, Ecological and Evolutionary Genetics
Identification Number or DOI: 10.1094/PHYTO-107-12-S5.196
URI: http://eprints.usq.edu.au/id/eprint/33778

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