Background: Recently in Japan, isolates resistant to boscalid, a succinate dehydrogenase inhibitor (SDHI), have been detected in Corynespora cassiicola (Burk. & Curt.) Wei and Podosphaera xanthii (Castaggne) Braun & Shishkoff, the pathogens causing Corynespora leaf spot and powdery mildew disease on cucumber, respectively. Resistant isolates of C. cassiicola are widely distributed and represent a serious problem in disease control at present. Novel SDHI fungicides, including fluopyram, are now under development.
Results: The growth of very highly boscalid-resistant, highly resistant and sensitive isolates of C. cassiicola was strongly suppressed on fluopyram-amended YBA agar medium. Although boscalid and another SDHI, penthiopyrad, hardly controlled Corynespora leaf spot and powdery mildew on cucumber plants when very highly or highly boscalid-resistant isolates were employed for inoculation, fluopyram still exhibited excellent control efficacy against these resistant isolates as well as sensitive isolates of C. cassiicola and P. xanthii.
Conclusion: Differential sensitivity to boscalid, penthiopyrad and fluopyram, clearly found in these two important pathogens of cucumber, may indicate involvement of a slightly distinct site of action for fluopyram from the two other SDHIs. This finding may lead to the discovery of unique SDHIs in the future.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/ps.2092 | DOI Listing |
Plant Dis
January 2019
Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Pestic Biochem Physiol
May 2017
Plant Pathology Laboratory, Faculty of Agriculture, Aristotelian University of Thessaloniki, PO Box 269, 54124 Thessaloniki, Greece.
Laboratory mutants of Penicillium expansum highly resistant (Rfs: 90 to >500, based on EC) to Succinate Dehydrogenase Inhibitors (SDHIs) were isolated after UV-mutagenesis and selection on media containing boscalid. A positive correlation was found between sensitivity of isolates to boscalid and other SDHIs such as isopyrazam and carboxin but not to fungicides affecting other cellular pathways or processes, such as the triazole flusilazole, the phenylpyrrole fludioxonil, the anilinopyrimidine cyprodinil and the benzimidazole benomyl. Most of the boscalid-resistant strains were more sensitive to the SDHI fluopyram and the QoI pyraclostrobin.
View Article and Find Full Text PDFMol Plant Pathol
September 2015
College of Plant Protection, Nanjing Agricultural University, National-Local Joint Engineering Research Center for Green Pesticide Invention and Application, Nanjing, 210095, China.
Research has established that mutations in highly conserved amino acids of the succinate dehydrogenase (SDH) complex in various fungi confer SDH inhibitor (SDHI) resistance. For Sclerotinia sclerotiorum (Lib.) de Bary, a necrotrophic fungus with a broad host range and a worldwide distribution, boscalid resistance has been attributed to the mutation H132R in the highly conserved SdhD subunit protein of the SDH complex.
View Article and Find Full Text PDFPlant Dis
February 2014
Department of Plant Pathology, University of California-Davis, Kearney Agricultural Research and Extension Center, Parlier.
Resistance of Alternaria alternata to boscalid, the first succinate dehydrogenase inhibitor (SDHI) fungicide labeled on pistachio, has become a common occurrence in California pistachio orchards and affects the performance of this fungicide. In this study, we established the baseline sensitivities of A. alternata to the new SDHIs fluopyram, fluxapyroxad, and penthiopyrad and assessed their cross resistance patterns with boscalid.
View Article and Find Full Text PDFPest Manag Sci
December 2014
Department of Soil, Plant and Food Sciences, University of Bari, Bari, Italy.
Background: Botryotinia fuckeliana (Botrytis cinerea) is a pathogen with a high risk of development of resistance to fungicides. Fungicide resistance was monitored during 2008-2011 in B. fuckeliana populations from both table-grape vineyards and greenhouse-grown strawberries in southern Italy.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!