Activity of fungicide mixtures againstBotrytis cinereaisolates resistant to benzimidazoles, strobilurins and dicarboximides

Abstract

Botrytis cinerea, the causal agent of grey mould in a broad range of crops, is considered a highrisk plant pathogen for fungicide resistance development. The use of fungicide mixtures, particularly combinations with synergistic activity, can be a useful tactic to counteract resistance build-up in pathogen populations. The present study aimed to investigate the effects of different ratios of two-way mixtures of carbendazim, iprodione, kresoxim-methyl, tebuconazole and penconazole on four B. cinerea isolates that were sensitive or resistant to benzimidazoles, dicarboximides and strobilurins. The isolates that were resistant to benzimidazoles and strobilurins had E198A and G143A mutations in β-tubulin and cytochrome b genes, respectively. The mixtures had different effects on each of the isolates in vitro but, in 13 combinations, the synergistic effect was observed against all or three isolates. In greenhouse experiments, 11 fungicide combinations used in decreased (EC 75 ) concentrations showed the maximum control efficiency.The two follow-up greenhouse experiments using six selected combinations revealed they were highly effective against additional isolates with various fungicide resistance profiles. The identified mixtures-ratios have potential for use in grey mould management programs in the greenhouse. K E Y W O R D Sfungicide resistance, fungicides interaction, grey mould, synergism

Chitosan and postharvest decay of fresh fruit: Meta‐analysis of disease control and antimicrobial and eliciting activities

“…Despite the efficacy of synthetic fungicides in the control of postharvest decay, public concerns about chemical and toxic residues in food (Belden, McMurry, Smith, & Reilley, 2010; Gonçalves et al., 2019; Liu, Yamdeu, Gong, & Orfila, 2020; Mebdoua, 2018) and the increase in drug‐resistant strains of many pathogens (Zuccolo et al., 2019) indicate the need for development of new strategies. Over the last few decades, there has been an increasing interest in the study of postharvest control methods that make use of natural resources (Ebrahimzadeh & Abrinbana, 2019; Guimarães, Abrunhosa, Pastrana, & Cerqueira, 2018; Liu et al., 2019; Liu et al., 2020; Palou, Smilanick, & Droby, 2008; Souza, Yuk, Khoo, & Zhou, 2015; Talibi, Boubaker, Boudyach, & Ait Ben Aoumar, 2014). Such alternative compounds can act as resistance inducers and/or activators of plant defense mechanisms, or they can have strong antimicrobial activities against the main postharvest fungal pathogens (Ribes, Fuentes, Talens, & Barat, 2018; Romanazzi, Feliziani, Baños, & Sivakumar, 2017).…”

PAImagem: uma ferramenta para quantificação de áreas em imagens de microbiologia

“…Determinar a suscetibilidade e capacidade de crescimento de microrganismos mediante diferentes parâmetros e exposição a compostos é de grande importância na microbiologia, não apenas para o entendimento da resposta dos microrganismos frente a compostos e condições específicas (Satapathy and Beura, 2019, Wang et al, 2019, Ebrahimzadeh and Abrinbana, 2019, Cáceres Candia, 2020, Kim et al, 2010, Zhang et al, 2017, mas também para investigar o desenvolvimento de resistência (Ghini and Kimati, 2000, Leroch et al, 2011, Hu et al, 2016 Existem vários métodos para determinar a capacidade de crescimento e a suscetibilidade antimicrobiana, incluindo difusão em disco, diluição em ágar ou micro-diluição em caldo (Balouiri et al, 2016). Todas essas técnicas são executadas em condições padronizadas (meios, temperaturas, tempos de incubação, entre outras), a fim de obter resultados interpretáveis, reprodutíveis e comparáveis.…”