Early Season Symptoms on Stem, Inflorescences and Flowers of Grapevine Associated with Botryosphaeriaceae Species.

Pedro Reis,Inês Lourenço,Cecília Rego,Florence Fontaine,Ana Gaspar,Artur Alves,Mariana Mota,José Saramago

doi:10.3390/plants9111427

Abstract

Botryosphaeria dieback caused by several Botryosphaeriaceae species is one of the most important grapevine trunk diseases affecting vineyards worldwide. These fungi cause wedge-shaped perennial cankers and black streaking of the wood and have also been associated with intervein leaf chlorosis, dried or mummified berries, and eventually, the death of the plant. Early season symptoms may sometimes be disregarded by growers, being mistaken with symptoms from other diseases such as downy mildew or botrytis rot. Currently, few studies are available to determine what species may be causing these early season symptoms in grapevines. During the 2018 season, during the flowering period, grapevine samples showing necrosis on green shoots, dried inflorescences, and flowers, were collected in vineyards throughout the central regions of Portugal. Isolations were performed from symptomatic organs, and twenty-three isolates of Botryosphaeriaceae were selected. An analysis of the ITS and part of the translation elongation factor 1-α sequences was performed, revealing that the two main species apparently responsible for these symptoms were Diplodia seriata and Neofusicoccum parvum. In pathogenicity tests conducted on 1-year-old plants grown under controlled conditions in a greenhouse and on field-grown clusters, symptoms were reproduced, confirming the pathogenic behavior of the selection of isolates.

Highlights

Grapevine trunk diseases (GTDs) are one of the most critical problems affecting viticulture worldwide, causing yield reduction and increased production costs adding to the existing cost of the annual vineyard operations
This is the first while studyno aimed at describingisolates grapevine early season from symptoms
This is the first studyonaimed at describing grapevine early season symptoms associated wilting of leaves, necrosis the peduncle and rachis of the developing clusters and, dryingwith of Botryosphaeriaceous fungi in Portugal, including necrosis and wilting of the apex of the green shoots, inflorescences and first flowers

Summary

Introduction

Grapevine trunk diseases (GTDs) are one of the most critical problems affecting viticulture worldwide, causing yield reduction and increased production costs adding to the existing cost of the annual vineyard operations. These diseases pose a significant threat to sustainable viticulture worldwide since the cost associated with GTD losses has been increasing during recent years. GTDs include three main fungal diseases—eutypa dieback, esca disease and botryosphaeria dieback—that involve. In Portugal, botryosphaeria dieback and Esca are considered the major diseases affecting adult grapevines, causing considerable economic losses, in all the country’s vine growing regions [2]

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