Molecular detection and identification of Diatrypaceous airborne spores in Australian vineyards revealed high species diversity between regions

Regina Billones-Baaijens; Meifang Liu; Mark R Sosnowski; Matthew R Ayres; Sandra Savocchia

doi:10.1371/journal.pone.0286738

Molecular detection and identification of Diatrypaceous airborne spores in Australian vineyards revealed high species diversity between regions

PLoS One. 2023 Jun 2;18(6):e0286738. doi: 10.1371/journal.pone.0286738. eCollection 2023.

Authors

Regina Billones-Baaijens¹, Meifang Liu², Mark R Sosnowski^{3

4}, Matthew R Ayres³, Sandra Savocchia^{1

2}

Affiliations

¹ Gulbali Institute, Charles Sturt University, Wagga Wagga, NSW, Australia.
² School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia.
³ South Australian Research and Development Institute, Adelaide, SA, Australia.
⁴ School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, Adelaide, SA, Australia.

Abstract

The grapevine trunk disease, Eutypa dieback (ED), causes significant vine decline and yield reduction. For many years, the fungus Eutypa lata was considered the main pathogen causing ED of grapevines in Australia. Recent studies showed other Diatrypaceous fungi were also associated with vines exhibiting dieback symptoms but there is limited information on how these fungal pathogens spread in vineyards. Thus, information on the spore dispersal patterns of Diatrypaceous fungi in different wine regions will assist in identifying high-risk infection periods in vineyards. Using more than 6800 DNA samples from airborne spores collected from eight wine regions in south-eastern Australia over 8 years using a Burkard spore trap, this study investigated the diversity and abundance of Diatrypaceous species, using multi-faceted molecular tools. A multi-target quantitative PCR (qPCR) assay successfully detected and quantified Diatrypaceous spores from 30% of the total samples with spore numbers and frequency of detection varying between regions and years. The high-resolution melting analysis (HRMA) coupled with DNA sequencing identified seven species, with E. lata being present in seven regions and the most prevalent species in the Adelaide Hills, Barossa Valley and McLaren Vale. Cryptovalsa ampelina and Diatrype stigma were the predominant species in the Clare Valley and Coonawarra, respectively while Eutypella citricola and Eu. microtheca dominated in the Hunter Valley and the Riverina regions. This study represents the first report of D. stigma and Cryptosphaeria multicontinentalis in Australian vineyards. This study further showed rainfall as a primary factor that triggers spore release, however, other weather factors that may influence the spore release in different climatic regions of Australia still requires further investigation.

Copyright: © 2023 Billones-Baaijens et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Australia
Farms
Spores, Fungal / genetics
Vitis* / microbiology
Xylariales*

Grants and funding

This work was supported by Wine Australia, with levies from Australia’s grape growers and winemakers and matching funds from the Australian Government and leverage funding from Charles Sturt University. Additional funding for Burkard spore traps was provided by Adelaide Hills Wine Region, Barossa Grape and Wine Association, Limestone Coast Grape and Wine Council, McLaren Vale Grape Wine and Tourism Association and Clare Region Winegrape Growers Association. The publication cost for this research was funded by the Tri-Faculty Open Access Publishing Scheme, Charles Sturt University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.