Trichothecene profiling and population genetic analysis of Gibberella zeae from barley in North Dakota and Minnesota

Burlakoti, Rishi R. and Neate, Stephen M. and Adhikari, Tika B. and Gyawali, Sanjaya and Salas, Bacilio and Steffenson, Brian J. and Schwarz, Paul B. (2011) Trichothecene profiling and population genetic analysis of Gibberella zeae from barley in North Dakota and Minnesota. Phytopathology, 101 (6). pp. 687-695. ISSN 0031-949X

Abstract

Gibberella zeae, the principal cause of Fusarium head blight (FHB) of barley, contaminates grains with several mycotoxins, which creates a serious problem for the malting barley industry in the United States, China, and Europe. However, limited studies have been conducted on the trichothecene profiles and population genetic structure of G. zeae isolates collected from barley in the United States. Trichothecene biosynthesis gene (TRI)-based polymerase chain reaction (PCR) assays and 10 variable number tandem repeat (VNTR) markers were used to determine the genetic diversity and compare the trichothecene profiles of an older population (n = 115 isolates) of G. zeae collected in 1997 to 2000 with a newer population (n = 147 isolates) collected in 2008. Samples were from across the major barley-growing regions in North Dakota and Minnesota. The results of TRI-based PCR assays were further validated using a subset of 32 and 28 isolates of G. zeae by sequence analysis and gas chromatography, respectively. TRI-based PCR assays revealed that all the G. zeae isolates in both populations had markers for deoxynivalenol (DON), and the frequencies of isolates with a 3-acetyldeoxynivalenol (3-ADON) marker in the newer population were ≈11-fold higher than those among isolates in the older population. G. zeae populations from barley in the Midwest of the United States showed no spatial structure, and all the isolates were solidly in clade 7 of G. zeae, which is quite different from other barley-growing areas of world, where multiple species of G. zeae are commonly found in close proximity and display spatial structure. VNTR analysis showed high gene diversity (H = 0.82 to 0.83) and genotypic diversity but low linkage disequilibrium (LD = 0.02 to 0.07) in both populations. Low genetic differentiation (FST = 0.013) and high gene flow (Nm = 36.84) was observed between the two populations and among subpopulations within the same population (Nm = 12.77 to 29.97), suggesting that temporal and spatial variations had little influence on population differentiation in the Upper Midwest. Similarly, low FST (0.02) was observed between 3-ADON and 15-acetyldeoxynivalenol populations, indicating minor influence of the chemotype of G. zeae isolates on population subdivision, although there was a rapid increase in the frequencies of isolates with the 3-ADON marker in the Upper Midwest between the older collection made in 1997 to 2000 and the newer collection made in 2008. This study provides information to barley-breeding programs for their selection of isolates of G. zeae for evaluating barley genotypes for resistance to FHB and DON accumulation.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2011 The American Phytopathological Society. Published version deposited in accordance with the copyright policy of the publisher.
Faculty / Department / School: Historic - Faculty of Sciences - Department of Biological and Physical Sciences
Date Deposited: 12 Jun 2014 06:08
Last Modified: 06 Feb 2018 01:18
Uncontrolled Keywords: Fusarium graminearum; Hordeum vulgare; population genetics
Fields of Research : 06 Biological Sciences > 0607 Plant Biology > 060704 Plant Pathology
06 Biological Sciences > 0605 Microbiology > 060505 Mycology
07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070308 Crop and Pasture Protection (Pests, Diseases and Weeds)
Socio-Economic Objective: B Economic Development > 82 Plant Production and Plant Primary Products > 8205 Winter Grains and Oilseeds > 820501 Barley
Identification Number or DOI: 10.1094/PHYTO-04-10-0101
URI: http://eprints.usq.edu.au/id/eprint/25193

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