Creative Commons

This dissertation was written as part of the MSc in Sustainable Agriculture and Business at the International Hellenic University. Over the last decades, fungicide resistance has become an even greater threat to the agricultural world. It is vital to understand in depth the resistance mechanisms and the effect of potential biocontrol agents. This literature-based dissertation focuses on creating a data pool, mainly over the last decade, concerning different traits of fungicides used against the plant pathogen Botrytis cinerea, while also analyzing Multidrug resistance (MDR) characteristics and potential microbes and extracts with anti-Botrytis effect. In this study, every class of botryticides is analyzed regarding the mode of action, resistance conferring mutations and resistance frequency. Particular importance is given to a couple of classes, anilinopyrimidines and phenylpyrroles, for which certain aspects, like their specific molecular target protein and resistance-conferring mutations are yet to be defined. Moreover, some insight is provided on the emergence of Multidrug resistance, being a phenomenon new to the agricultural worlds, with MDR1h phenotype displaying unexpectedly higher frequencies, significantly wider distribution and greater resistance levels compared to the other Multidrug resistant phenotypes. Finally, certain newly published potential biocontrol agents are summarized, in particular their effect and results. Bacteria in the genus Bacillus and certain fungal species like Aureobasidium sp. and Candida sp. seem to exhibit the greatest effect in inhibiting the growth of B. cinerea and thus the grey mould disease. Concerning Target-site resistance, it is a common phenomenon in Botrytis because the principal method for controlling this pathogen is chemical control. However, the repeated use of fungicides harbours many dangers and threats, one of them being fungicide resistance development. In addition, Botrytis cinerea biology renders it a high risk ii pathogen concerning resistance development. Target-site alterations in some gene targets grant resistance to different fungicide classes. Regarding B. cinerea, there have been found mutations, granting resistance to almost every class of botryticides currently in use. Apart from target-site resistance, Multidrug resistance has also been recently discovered in B. cinerea. MDR is a known phenomenon in medicine, since it occurs in cancer cells and human pathogenic Candida spp., making their treatment way more demanding. It involves mutations in certain genes, leading to overexpression of drug efflux pumps of the cell, granting simultaneous resistance against many different-mode-of-action drugs