Occurrence of fungicide resistance in populations of Botryotinia fuckeliana (Botrytis cinerea) on table grape and strawberry in southern Italy

Abstract

BACKGROUND: Botryotinia fuckeliana (Botrytis cinerea) is a pathogen with a high risk of development of resistance to fungicides. Fungicide resistance was monitored during 2008-2011 in B. fuckeliana populations from both table-grape vineyards and greenhouse-grown strawberries in southern Italy. RESULTS:Isolates showing different levels of resistance to anilinopyrimidines (APs) were detected at high frequency (up to 98%) in fields treated intensively with APs (4-7 sprays season −1 ). A slight decrease in sensitivity to fludioxonil, always combined with AP resistance, was generally found at lower frequencies. The repeated use of fenhexamid on grapevine (3-8 sprays season −1 ) led to a strong selection of highly resistant isolates (up to 100%). Boscalid-resistant mutants were detected at very variable frequencies (0-73%). Occurrence of resistance to quinone outside inhibitors (QoIs) was also ascertained. Multiple fungicide resistance to 2-6 different modes of action were frequently recovered. Single nucleotide polymorphisms (SNPs) in the target genes Erg27, SdhB and cytb were associated with resistance to fenehexamid, boscalid and QoIs respectively. CONCLUSION: Resistance to the fungicides commonly used against grey mould on table grape and strawberry is quite common in southern Italy. This is an outcome of the incorrect use of fungicides, often because of the maximum number of detectable residues of plant protection products imposed by big international retailers, and underlines the crucial role of antiresistance strategies in integrated pest management.

Frequency of fungicide-resistant Botrytis cinerea populations isolated from ‘Thompson Seedless’ table grapes in the Central Valley of Chile

“…PCR amplification was performed using two specific primer pairs to amplify partially overlapping fragments of the erg27 gene of B. cinerea: Fnx.42 andFnx.1197, andFnx.844 andFnx.2007 (Table 1). PCR amplifications were conducted using the parameters described by De Miccolis Angelini et al (2014).…”

Baseline sensitivity and efficacy of fluopyram against Botrytis cinerea from table grape in Italy

“…MBCs, dicarboximides, APs etc.) in Italy (De Miccolis Angelini et al, 2014b;Panebianco et al, 2015), more or less recent fungicides (SDHIs fluopyram and boscalid) have been introduced into the Italian marketplace. In this article, we determined the sensitivity to fluopyram for each B. cinerea isolate collected from Sicilian vineyards.…”

Gray mold caused by Botrytis cinerea limits grape production in Chile

“…Recently, multiple resistance has been reported in B. cinerea in grapes in Chile (Latorre and Torres, 2012) and other countries (De Miccolis Angelini et al, 2014;Leroch et al, 2011). This reflects the danger of the intensive use of fungicides against GM and reinforces the fact that fungicide resistance is a serious threat to the grape industry.…”

“…The foliar application of fungicides is used to protect the grape cluster and reduce the infection rate (r) as much as possible during the growing season. Nevertheless, the use of fungicides is increasingly restricted because of major environmental and human health concerns (Komárek et al, 2010) and because of the frequent development of resistant strains of B. cinerea (De Miccolis Angelini et al, 2014;Latorre and Torres, 2012;Leroux, 2004;Leroux et al, 2002).…”