Diversity of Fusarium species isolated from UK forage maize and the population structure of F. graminearum from maize and wheat.

Ryan Basler

doi:10.7717/peerj.2143

Abstract

Pre-harvest contamination of forage maize by mycotoxin producing Fusarium species was investigated in the UK in 2011 and 2012. A total of 15 Fusarium species were identified from a collection of 1,761 Fusarium isolates recovered from maize stalks and kernels. This study characterized the diversity of Fusarium species present in forage maize in the UK. The predominant species detected were F. graminearum (32.9%) and F. culmorum (34.1%). Along with those species; F. avenacem, F. cerealis, F. equiseti, F. langsethiae, F. napiforme, F. oxysporum, F. poae, F. proliferatum, F. scripi, F. solani, F. subglutinans, F. tricinctum and, F. verticillioides were occasionally isolated. The trichothecene genotypes for F. graminearum were determined to be 84.9% deoxynivalenol (DON) and 15.0% nivalenol (NIV) while F. culmorum isolates were determined to have 24.9% DON and 75.1% NIV genotypes. A Bayesian model-based clustering method with nine variable number of tandem repeat markers was used to evaluate the population genetic structure of 277 F. graminearum isolates from the maize and wheat in the UK. There were three genetic clusters detected which were DON in maize, NIV in maize and DON in wheat. There were high admixture probabilities for 14.1% of the isolates in the populations. In conclusion, increased maize production in the UK and the high admixture rates in a significant portion of F. graminearum populations in maize and wheat will contribute to a new pathogen population which will further complicate breeding strategies for tolerance or resistance to this pathogen in both crops.

Highlights

Maize is one of the most important crops worldwide, with the cropping area of the 27 member states of the European Union (EU) reaching 9.7 million ha for grain maize and 5.9 million ha for forage maize in 2013
This study identified fifteen Fusarium species in maize with the predominant species being: F. graminearum (32.9%), F. culmorum (34.1%), F. solani (19.8%), F. cerealis (3.5%), F. avenaceum (3.0%) and F. poae (2.8%)
Other Fusarium species identified in the collection were: F. oxysporum (1.2%), F. verticillioides (1.1%), F. proliferatum (0.4%), F. tricinctum (0.3%), F. subglutinans (0.3%), F. langsethiae (0.2%), F. napiforme (0.2%), F. equiseti (0.2%) and one isolate of F. scripi (Table 2)

Summary

Introduction

Maize is one of the most important crops worldwide, with the cropping area of the 27 member states of the European Union (EU) reaching 9.7 million ha for grain maize and 5.9 million ha for forage maize in 2013. With climate change and the establishment of maize varieties tolerant to cooler climates, regions like the UK have seen an increase in maize production. How to cite this article Basler (2016), Diversity of Fusarium species isolated from UK forage maize and the population structure of F. graminearum from maize and wheat. The main markets for maize in the EU are for human consumption, animal feed and bioenergy

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