Fitness of Botrytis cinerea Associated with Dicarboximide Resistance

Abstract

Fitness costs in Botrytis cinerea associated with dicarboximide resistance were studied. Spearman rank correlation coefficients were calculated between resistance to iprodione and survival ability both outside and inside the greenhouse, measured on isolates randomly chosen from a collection done in a survey of commercial greenhouses in Southeastern Spain in 1992. Survival was measured at 47, 83, and 110 days as percentage of surviving mycelia in a sample of artificially inoculated tomato stem pieces and as percentage of viable sclerotia from a sample of sclerotia produced on potato dextrose agar. Resistance to iprodione was measured by the fungicide concentration that reduces fungal growth by 50% (EC(50) values). Significant (P < 0.05) negative correlation coefficients between survival of sclerotia and resistance to iprodione were found for some samplings dates, which indicates that sclerotia of resistant isolates survive less well than sclerotia from sensitive isolates. For mycelia, no relationship between survival and resistance was found.

PMKT2, a new killer toxin from Pichia membranifaciens, and its promising biotechnological properties for control of the spoilage yeast Brettanomyces bruxellensis

“…Traditionally, biocides have been used to deal with these problems but different disadvantages such as establishment of resistant strains and suppression of natural competitors have made alternatives such as biological control necessary (Beever et al, 1989;Raposo et al, 2000). Biological control strategies include natural plant-and animal-derived compounds, as well as antagonistic micro-organisms (Ciani & Fatichenti, 2001).…”

Killer toxin of Pichia membranifaciens and its possible use as a biocontrol agent against grey mould disease of grapevine

“…Chemical control of Botrytis has been partially successful and fungicides are commonly used in the management of grey mould. However, the risk of the establishment of resistant Botrytis strains is considerable (Beever et al, 1989;Raposo et al, 2000). Factors related to the efficiency of such agents include the timing of application, thoroughness of coverage, and in the case of certain systemic fungicides, build-up of Botrytis strains with fungicide tolerance; fungicides then only serve to suppress natural competitors, often rendering the disease even more severe (Beever et al, 1989;Raposo et al, 2000).…”

“…However, the risk of the establishment of resistant Botrytis strains is considerable (Beever et al, 1989;Raposo et al, 2000). Factors related to the efficiency of such agents include the timing of application, thoroughness of coverage, and in the case of certain systemic fungicides, build-up of Botrytis strains with fungicide tolerance; fungicides then only serve to suppress natural competitors, often rendering the disease even more severe (Beever et al, 1989;Raposo et al, 2000). With rekindled public concern about environmental issues, together with the awareness that upsetting the natural microbial balance can lead to severe outbreaks of disease, plant pathologists are increasingly interested in the possibilities of biological control.…”

Divergence in Fitness and Evolution of Drug Resistance in Experimental Populations of Candida albicans

“…Whether drug-resistant organisms persist in nature depends on their fitness relative to drug-sensitive organisms. Correlations between resistance to fungicides and fitness traits such as latency, sporulation, and survival of plant-pathogenic fungi have provided mixed results: that there is no cost of resistance (34), that there is a cost for survival of resistant propagules but not somatic cells (35); and that there is a cost not correlated with any specific trait (15,18). The evolutionary dynamics of drug resistance and its fitness costs have been studied in viruses (8,31) and bacteria (2,6,7,25,38) but not in a comparable way in fungi, despite their increasing importance as opportunistic pathogens of humans (1,14,17).…”