Determination of natural resistance frequencies in Penicillium digitatum using a new air-sampling method and characterization of fludioxonil- and pyrimethanil-resistant isolates

Phytopathology
Loukas KanetisJames E Adaskaveg

Abstract

ABSTRACT Fungicide resistance was identified in natural populations of Penicillium digitatum, the causal agent of green mold of citrus, to two of three new postharvest fungicides before their commercial use. Using a new air-sampling method where large populations of the pathogen in citrus packinghouses were exposed to agar plates with a continuous, wide-range fungicide concentration gradient, isolates with reduced sensitivity to fludioxonil or pyrimethanil were obtained. Resistance frequencies to fludioxonil and pyrimethanil were calculated as 9.5 x 10(-7) to 1.5 x 10(-5) and 7.3 x 10(-6) to 6.2 x 10(-5), respectively. No isolates resistant to azoxystrobin were detected. Isolates with reduced sensitivity to fludioxonil or pyrimethanil were also obtained in laboratory selection studies, where high concentrations of conidial mixtures of isolates sensitive to the three fungicides were plated onto agar amended with each fungicide at 10 microg/ml. Isolates obtained from fludioxonil selection plates in laboratory and packinghouse experiments were placed into two categories based on mycelial growth: moderately resistant isolates had 50% effective concentration (EC(50)) values of 0.1 to 0.82 microg/ml and highly resistant isolates had ...Continue Reading

References

Jul 18, 1953·Nature·G PONTECORVO, G SERMONTI
Oct 24, 2008·Phytopathology·G A BardasG S Karaoglanidis

❮ Previous
Next ❯

Related Concepts

Related Feeds

Antimicrobial Resistance (ASM)

Antimicrobial resistance poses a significant threat to the continued successful use of antimicrobial agents for the treatment of bacterial infections.

Antimicrobial Resistance

Antimicrobial resistance poses a significant threat to the continued successful use of antimicrobial agents for the treatment of bacterial infections.

Anthelmintics

Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. Discover the latest research on anthelmintics here.

Antifungals

An antifungal, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis, cryptococcal meningitis, and others. Discover the latest research on antifungals here.