Two isolates of Neofusicoccum australe belonging to ITS haplotypes H4 and H1 and associated with grapevine cordon dieback and branch dieback of Phoenicean juniper, respectively, have been shown to produce in vitro structurally different secondary metabolites. From the strain BOT48 of N. australe (haplotype H4) a new cyclohexenone oxide, namely, cyclobotryoxide, was isolated together with 3-methylcatechol and tyrosol. Cyclobotryoxide was characterized as (1S,5R,6S)-5-hydroxy-3-methoxy-4-methyl-7-oxabicyclo[4.1.0]hept-3-en-2-one by spectroscopic, optical, and chemical methods. The strain BL24 (haplotype H1) produced tyrosol along with botryosphaerone D and (3S,4S)-3,4,8-trihydroxy-6-methoxy-3,4-dihydro-1(2H)-naphthalenone. The metabolites obtained from both strains were tested at four concentrations on leaves of grapevine cv. Cannonau, holm oak, and cork oak by the leaf puncture assay. Cyclobotryoxide proved to be the most phytotoxic compound. Tyrosol and cyclobotryoxide were also tested on detached grapevine leaves at concentrations of 0.25 and 0.5 mg/mL. Only cyclobotryoxide was found to be active in this bioassay.
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http://dx.doi.org/10.1021/np300512m | DOI Listing |
Microorganisms
February 2023
Unidad de Protección Vegetal, Instituto Canario de Investigaciones Agrarias, 38270 San Cristóbal de La Laguna, Spain.
Fungi of the family Botryosphaeriaceae are considered responsible for various symptoms in avocado such as dieback, external necrosis of branches and inflorescences, cankers on branches and trunks, or stem-end rot of fruits. In recent years, these problems are becoming more frequent in avocado orchards in the Canary Islands (Spain). This work includes the characterization of fungal species involved in these diseases, which were isolated from avocado crops in Tenerife Island between 2018 and 2022.
View Article and Find Full Text PDFPlant Dis
February 2023
Instituto de Investigaciones Agropecuarias, 60705, INIA La Platina, Avenida Santa Rosa 11610, Santiago, Santiago, Chile, 8831314.
The English walnut ( L.) is the second most important fruit crop of importance in Chile, with 43,700 hectares mainly in the Central Valley (www.odepa.
View Article and Find Full Text PDFPlant Dis
August 2022
Stellenbosch University, Plant Pathology, Private BagX1, Matieland, Stellenbosch, Western Cape, South Africa, 7602.
Honeybush ( spp.) is an indigenous, leguminous member of the Cape fynbos biome growing in the coastal winter rainfall districts of the Western and Eastern Cape Provinces of South Africa (Joubert et al. 2011).
View Article and Find Full Text PDFPhytopathology
November 2022
Ecology, Evolution, and Marine Biology Department, University of California, Santa Barbara, CA 93106.
Dieback and mortality in wildland plant species due to climate change have been on the rise in recent decades, and latent fungal pathogens might play a significant role in these events. During a severe multiyear drought, canopy dieback associated with latent pathogens in the Botryosphaeriaceae () family was observed in stands of a dominant shrub species, big berry manzanita (), across chaparral landscapes in California. These fungi are significant pathogens of woody agricultural species, especially in hosts experiencing stress, and have become a threat to economically important crops worldwide.
View Article and Find Full Text PDFBMC Microbiol
May 2022
Canterbury Agriculture and Science Centre, The New Zealand Institute for Plant and Food Research Limited, Gerald St, Lincoln, 7608, New Zealand.
Grapevine trunk diseases (GTDs) are a threat to grape production worldwide, with a diverse collection of fungal species implicated in disease onset. Due to the long-term and complex nature of GTDs, simultaneous detection of multiple microbial species can enhance understanding of disease development. We used DNA metabarcoding of ribosomal internal transcribed spacer 1 (ITS1) sequences, supported by specific PCR and microbial isolation, to establish the presence of trunk pathogens across 11 vineyards (11-26 years old) over three years in Marlborough, the largest wine producing region in New Zealand.
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