The Establishment and Spread of a Newly Introduced Begomovirus in a Dry Tropical Environment Using Tomato Yellow Leaf Curl Virus as a Case Study.

Cherie Gambley,Peter Nimmo,Janet Mcdonald,Paul Campbell

doi:10.3390/plants11060776

Cherie Gambley, Peter Nimmo + Show 2 more

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https://doi.org/10.3390/plants11060776

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Abstract

Early detection of tomato yellow leaf curl virus (TYLCV) in a previously unaffected tomato production district in Australia allowed its spread to be evaluated spatially and temporally. The population dynamics of the TYLCV vector, Bemisia argentifolii (silverleaf whitefly, SLW), were also evaluated. The district is a dry tropical environment with a clear break to commercial production during the summer wet season. The incidence of TYLCV within crops and its prevalence through the district was influenced by weather, location, vector movements, and the use of Ty-1 virus-resistant hybrids. Rainfall had an important influence, with late summer and early autumn rain suppressing the levels of SLW and, by contrast, a dry summer supporting faster population growth. The use of Ty-1 hybrids appears to have reduced the incidence of TYLCV in this district. There was limited use of Ty-1 hybrids during 2013, and by season end, crops had moderate levels of SLW and high virus incidence. The 2015 and early 2016 season had high SLW populations, but TYLCV incidence was lower than in 2013, possibly due to the widespread adoption of the Ty-1 hybrids reducing virus spread. This study provides valuable epidemiology data for future incursions of begomoviruses, and other viruses spread by SLW.

Highlights

Academic Editor: Francesco DiThe International Committee for the Taxonomy of Viruses (ICTV) currently recognises408 species within the Begomovirus genus [1]
Potential change in virus diversity was monitored by whole genome sequencing of reference tomato yellow leaf curl virus (TYLCV) isolates collected in the Bowen district in 2011, 2013, and 2015
The relatively recent introduction of TYLCV into a new production district allowed the spread of a begomovirus to be monitored spatially and temporally in a dry tropics environment which has a clear break in crop production

Summary

Introduction

Academic Editor: Francesco DiThe International Committee for the Taxonomy of Viruses (ICTV) currently recognises408 species within the Begomovirus genus [1]. Begomoviruses are a concern for tropical and sub-tropical agricultural areas and an increasing problem in temperate protected cropping systems [2]. These viruses are transmitted in a persistent, circulative manner through the active or passive flight of infective (viruliferous) adult insects from whitefly species belonging to the Bemisia genus (Hemiptera: Alyerodidae) [3]. This includes silverleaf whitefly (SLW), which is widely distributed in Australian tropical and subtropical horticulture, cotton, and grains cropping regions [4], and as such, these major production areas are at risk of exotic begomovirus incursions. In Australia, the diversity of Bemisia spp. is thought to be very low and dominated by SLW [4–6]

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