Muharrem Türkkan, Tuğba Bozoğlu, Sibel Derviş, İsmail Erper, Göksel Özer
{"title":"Armillaria Species Causing Kiwifruit Vine Decline and Root Rot in Northeastern Türkiye: A Growing Concern for Kiwifruit Health","authors":"Muharrem Türkkan, Tuğba Bozoğlu, Sibel Derviş, İsmail Erper, Göksel Özer","doi":"10.1111/jph.13409","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>Kiwifruit (<i>Actinidia deliciosa</i>) production in northeastern Türkiye is facing an emerging threat from Armillaria root rot. Surveys conducted in August 2021 and 2022 revealed that 10.5%–17.5% of the 200–500 vines within each of 35 kiwifruit orchards in the Perşembe, Gülyalı and Altınordu districts of Ordu province exhibited symptoms of Armillaria root rot, including complete defoliation. Diseased plants exhibited diagnostic signs on their root collars and woody roots, including white mycelial fans, extensive wood rot and rhizomorphs. A single <i>Armillaria</i> isolate was obtained from each of the 35 symptomatic orchards. Molecular identification, employing DNA sequencing of the large subunit (LSU) region of rDNA, the translation elongation factor subunit 1-alpha (<i>TEF1</i>) gene and the second largest RNA polymerase II B-subunit (<i>RPB2</i>) gene, identified 20 isolates as <i>Armillaria gallica</i> and 15 as <i>A</i>. <i>mellea</i>. Phylogenetic analyses, based on <i>TEF1</i> alignments, further supported the species identification with a 100% bootstrap value. To examine genetic diversity, start codon targeted (SCoT) marker 13 was used, successfully differentiating the two <i>Armillaria</i> species and revealing three distinct clades. Clades I and II comprised 15 and 5 isolates of <i>A</i>. <i>gallica</i>, respectively, while Clade III contained all 15 <i>A</i>. <i>mellea</i> isolates. Pathogenicity testing on kiwifruit seedlings (cv. Hayward) revealed the ability of both <i>A</i>. <i>gallica</i> and <i>A</i>. <i>mellea</i> isolates to induce disease. Rhizomorph-producing isolates in kiwifruit seedlings displayed high virulence, inducing severe leaf necrosis and seedling mortality, while isolates lacking these structures were non-pathogenic. This study identifies the first global instance of <i>A</i>. <i>gallica</i> causing kiwifruit root rot. This finding, along with the identification of <i>A</i>. <i>mellea</i> as a causal agent in the country, highlights the emerging threat of Armillaria root rot to kiwifruit production in the region.</p>\n </div>","PeriodicalId":16843,"journal":{"name":"Journal of Phytopathology","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Phytopathology","FirstCategoryId":"97","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/jph.13409","RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Kiwifruit (Actinidia deliciosa) production in northeastern Türkiye is facing an emerging threat from Armillaria root rot. Surveys conducted in August 2021 and 2022 revealed that 10.5%–17.5% of the 200–500 vines within each of 35 kiwifruit orchards in the Perşembe, Gülyalı and Altınordu districts of Ordu province exhibited symptoms of Armillaria root rot, including complete defoliation. Diseased plants exhibited diagnostic signs on their root collars and woody roots, including white mycelial fans, extensive wood rot and rhizomorphs. A single Armillaria isolate was obtained from each of the 35 symptomatic orchards. Molecular identification, employing DNA sequencing of the large subunit (LSU) region of rDNA, the translation elongation factor subunit 1-alpha (TEF1) gene and the second largest RNA polymerase II B-subunit (RPB2) gene, identified 20 isolates as Armillaria gallica and 15 as A. mellea. Phylogenetic analyses, based on TEF1 alignments, further supported the species identification with a 100% bootstrap value. To examine genetic diversity, start codon targeted (SCoT) marker 13 was used, successfully differentiating the two Armillaria species and revealing three distinct clades. Clades I and II comprised 15 and 5 isolates of A. gallica, respectively, while Clade III contained all 15 A. mellea isolates. Pathogenicity testing on kiwifruit seedlings (cv. Hayward) revealed the ability of both A. gallica and A. mellea isolates to induce disease. Rhizomorph-producing isolates in kiwifruit seedlings displayed high virulence, inducing severe leaf necrosis and seedling mortality, while isolates lacking these structures were non-pathogenic. This study identifies the first global instance of A. gallica causing kiwifruit root rot. This finding, along with the identification of A. mellea as a causal agent in the country, highlights the emerging threat of Armillaria root rot to kiwifruit production in the region.
期刊介绍:
Journal of Phytopathology publishes original and review articles on all scientific aspects of applied phytopathology in agricultural and horticultural crops. Preference is given to contributions improving our understanding of the biotic and abiotic determinants of plant diseases, including epidemics and damage potential, as a basis for innovative disease management, modelling and forecasting. This includes practical aspects and the development of methods for disease diagnosis as well as infection bioassays.
Studies at the population, organism, physiological, biochemical and molecular genetic level are welcome. The journal scope comprises the pathology and epidemiology of plant diseases caused by microbial pathogens, viruses and nematodes.
Accepted papers should advance our conceptual knowledge of plant diseases, rather than presenting descriptive or screening data unrelated to phytopathological mechanisms or functions. Results from unrepeated experimental conditions or data with no or inappropriate statistical processing will not be considered. Authors are encouraged to look at past issues to ensure adherence to the standards of the journal.