Genetic Basis and Monitoring of Resistance of Botryotinia fuckeliana to Anilinopyrimidines

Abstract

The anilinopyrimidines constitute a new class of mainly protective, broad-spectrum fungicides with a high activity against Botryotinia fuckeliana, the causal agent of gray mold on a wide range of host plants. The present study was initiated to investigate the genetic basis of resistance to anilinopyrimidines in B. fuckeliana and to assess the frequency of resistant isolates in vineyards in Switzerland exposed to experimental applications of anilinopyrimidines. In mating experiments, two sensitive reference isolates were crossed with three anilinopyrimidine-resistant field isolates. The analysis of 72 sexual progeny from six apothecia demonstrated that resistance to the anilinopyrimidine fungicide cyprodinil segregated in a 1:1 ratio and is therefore monogenic. The same segregation ratio was found for resistance to the dicarboximide fungicide vinclozolin. Resistance to cyprodinil segregated independently from resistance to vinclozolin. From 1993 to 1995, isolates of B. fuckeliana were collected in Switzerland from five vineyards that differed in their anilinopyrimidine spray history. Of a total of 303 isolates tested in vitro, three anilinopyrimidine-resistant isolates were detected in two vineyards where the cumulative number of treatments was between two and nine. The results of the study are discussed with respect to the implementation of an antiresistance strategy in Switzerland.

Effect of <i>Trichoderma harzianum</i> in Combination with Fungicides in Controlling Gray Mould Disease (<i>Botrytis cinerea</i>) of Strawberry

“…Furthermore, it was noted that moderate sensi-tivity of T. harzianum to cyprodinil and fludioxonil is due to active ingredients of two different families with two different modes of actions [20]. In addition, T. harzianum (Jn14) was almost insensitive to Pyrimethanil.…”

Genetic diversity in Botrytis cinerea populations on vegetable crops in greenhouses in south‐eastern Spain

“…Genetic analysis of laboratory mutants of B. cinerea resistant to the phenylpyrrole fungicide CGA 173506 showed that, in most mutants, resistance was caused by a single gene (Faretra & Pollastro, 1993b). Recently, Hilber & Hilber-Bodmer (1998) demonstrated that resistance to the anilinopyrimidine fungicide cyprodinil segregated in a 1 : 1 ratio and is therefore probably monogenic.…”

Detection of Fungicide Resistance

“…One of the first studies ) that screened multiple fungicide resistances in B. cinerea found resistance to anilopyrimidines (AP, e.g. cyprodinil, mepanipyrim, pyrimethanil) and identified two distinct resistance phenotypes: The most AP-resistant isolates were resistant to only anilinopyrimidines, suggesting action on the hitherto unidentified, single target gene (Hilber and Hilber-Bodmer 1998) and a second phenotype that included resistance to distinctly different classes of fungicides including dicarboximides, phenylpyrroles, sterol biosynthesis inhibitors (e.g. tolfanate, prochloraz, tebuconazole) and the hydroxyanilide derivative, fenhexamid, consistent with an MDR phenotype.…”