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Morphological characteristics of Colletotrichum isolates from walnut anthracnose cultured on PDA for 5 days. (a) and (b), upper and reverse view of colonies. (c), conidia. Scale bar = 20 μm.
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Walnuts (Juglans regia L.) are a major food crop in Beijing. Recently, walnut anthracnose has become a serious problem in walnut plantations of Beijing, and the diversity of pathogens that cause this disease is poorly understood, making targeted treatment difficult. This study investigated incidences of walnut anthracnose in seven districts of Beij...
Citations
... Morphological characteristics including the size and shape of spores (n = 20) were measured and photographed. The morphological structures were compared to the known fungal species described in the literature and partially identified according to the taxonomic studies by Tan et al. [19] and Li et al. [20]. ...
... PSU-108 conidia were 5.75-7.34 (6.51 ± 0.46) [19,20,28]. This isolate was deposited in the Culture Collection of Pest Management, Faculty of Natural Resources, Prince of Songkla University, Thailand, with the accession code PSU-109. ...
... Accurate identification of the pathogen is the basis for the establishment of effective management strategies. Between 2015 and 2022, Colletotrichum viniferum, C. fructicola, C. siamense, C. aenigma, C. kahawae, C. liaoningense, C. sojae, C. nymphaeae, C. godetiae, C. juglandis, and C. fioriniae were isolated from walnut leaves or fruits, which were identified using multilocus phylogeny, morphological characteristics, and cultural properties (He et al. 2019;Li et al. 2023;Ma et al. 2022;Wang et al. 2017Wang et al. , 2018Wang et al. 2021Wang et al. , 2023Wei et al. 2022;Zhu et al. 2015), and the results were more reliable. ...
Walnut is cultivated around the world for its precious woody nut and edible oil. Recently, walnut infected by Colletotrichum spp. resulted in a great yield and quality loss. In August and September 2014, walnut fruits with anthracnose were sampled from two commercial orchards in Shaanxi and Liaoning provinces, and five representative isolates were used in this study. To identify the pathogen properly, four genes/region (internal transcribed spacer, glyceraldehyde-3phosphate dehydrogenase, actin, and chitin synthase) were sequenced and used in phylogenetic studies. Based on multi-locus phylogenetic analysis, five isolates clustered with C. fioriniae including its ex-type with 100% bootstrap support. The results of multi-locus phylogenetic analyses, morphology and pathogenicity confirmed that C. fioriniae was one of the walnut anthracnose pathogens in China. All 13 fungicides tested inhibited mycelial growth and spore germination. Flusilazole, fluazinam, prochloraz, and pyraclostrobin showed the strongest suppressive effects on the mycelial growth than the others, the average EC50 values were from 0.09 to 0.40 μg/mL, and there was not any significant difference (P < 0.05). Pyraclostrobin, thiram, and azoxystrobin were the most effective fungicides on spore germination (P<0.05), and the EC50 values ranged from 0.01 to 0.44 μg/mL. Pyraclostrobin, azoxystrobin, fluazinam, flusilazole, mancozeb, thiram, and prochloraz exhibited good control effect on walnut anthracnose caused by C. fioriniae, and preventive activities were greater than curative activities. Pyraclostrobin at 250 a.i. μg/mL, and fluazinam 500 a.i. μg/mL provided the highest preventive and curative efficacy and the values were from 81.3% to 82.2%, from 72.9 % to 73.6 %, respectively. As a consequence, mancozeb and thiram could be used at the preinfection stage, pyraclostrobin, azoxystrobin, flusilazole, fluazinam, and prochloraz could be selected at the early stage, for effective prevention and control of walnut anthracnose caused by C. fioriniae. The results will provide more significant instruction for controlling the disease effectively in Northern China.
... Colletotrichum godetiae caused severe anthracnose of walnut in Shaanxi Province and Yunnan Province with diseased fruits over 60% in the orchard . Li et al. (2023) collected 900 walnut leaves and 300 fruits samples from seven districts of Beijing and 377 isolates of Colletotrichum spp. were identified into six species, namely C. aenigma, C. fructicola, C. gloeosporioides, C. siamense, C. liaoningense and C. sojae. ...
... Colletotrichum peakense can be distinguishable from C. citrulli, C. dimorphum, C. gloeosporioides and C. nanhuaensis by its longer setae and smaller appressorial size (Table 2). Thus far, 14 species of Colletotrichum have been reported from Juglans regia L., namely C. acutatum, C. fioriniae, C. godetiae, C. juglandis and C. nymphaeae of the Acutatum species complex, C. aenigma, C. fructicola, C. gloeosporioides, C. kahawae, C. mengyinense, C. siamense and C. viniferum of Gloeosporioides species complex, C. liaoningense of Magnum species complex and C. sojae of Orchidearum species complex (Simmonds 1966;Alvarez 1976;Gorter 1977;Pennycook 1989;Liu et al. 1995;Crous et al. 2000;Chen 2003;Cho and Shin 2004;Gadgil et al. 2005;Juhásová et al. 2005;Sreenivasaprasad and Talhinhas 2005;Kobayashi 2007;Qu et al. 2011;Damm et al. 2012;Zhu et al. 2014;Zhu et al. 2015;Wang et al. 2017Wang et al. , 2018Da Lio et al. 2018;He et al. 2019;Savian et al. 2019;Wang et al. 2020;Wang et al. 2021Wang et al. , 2023Luongo et al. 2022;Ma et al. 2022;Wei et al. 2022;Li et al. 2023), of which, Colletotrichum acutatum, C. fioriniae, C. godetiae, C. juglandis and C. nymphaeae differed from C. juglandicola and C. peakense by their acute-ended conidia . Colletotrichum aenigma, C. fructicola, C. gloeosporioides, C. kahawae, C. mengyinense, C. siamense and C. viniferum differed from C. juglandicola and C. peakense, by the size of conidia ( Table 2). ...
... Both on fruits and leaves, the virulence of C. peakense was more severe than C. juglandicola (P < 0.05). Colletotrichum gloeosporioides had been reported more severe than most other species in Beijing, which was supported by the current study in that C. gloeosporioides was more severe than C. juglandicola (12.33 ± 0.29 mm in 4 days vs. 8.90 ± 2.28 mm in 10 days) (Li et al. 2023). ...
Colletotrichum species are plant pathogens, saprobes and endophytes on various plant hosts. It is regarded as one of the 10 most important genera of plant pathogens in the world. Walnut anthracnose is one of the most severe diseases affecting walnut productivity and quality in China. In this study, 162 isolates were obtained from 30 fruits and 65 leaf samples of walnut collected in Beijing, China. Based on morphological characteristics and DNA sequence analyses of the concatenated loci, namely internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase ( GAPDH ), actin ( ACT ), chitin synthase 1 ( CHS-1 ) and beta-tubulin (TUB2), these isolates were identified as two novel species of Colletotrichum , i.e. C. juglandicola and C. peakense . Koch’s postulates indicated that both C. juglandicola and C. peakense could cause anthracnose in walnut.
... identified to date. The host range of C. viniferum has been expanding, with new hosts identified including strawberry [81], walnut [81,82], chili [83] in China, pomegranate in India [84], and Hopea odorata [85] in Bangladesh. ...
Grape ripe rot, which is predominantly caused by the Colletotrichum species, presents a growing threat to global grape cultivation. This threat is amplified by the increasing populations of the Colletotrichum species in response to warmer climates. In this review, we investigate the wide-ranging spectrum of grape ripe rot, specifically highlighting the role and characteristics of the C. gloeosporioides species complex (CGSC). We incorporate this understanding as we explore the diverse symptoms that lead to infected grapevines, their intricate life cycle and epidemiology, and the escalating prevalence of C. viniferum in Asia and globally. Furthermore, we delve into numerous disease management strategies, both conventional and emerging, such as prevention and mitigation measures. These strategies include the examination of host resistances, beneficial cultivation practices, sanitation measures, microbiome health maintenance, fungicide choice and resistance, as well as integrated management approaches. This review seeks to enhance our understanding of this globally significant disease, aspiring to assist in the development and improvement of effective prevention and control strategies.
... Five conventional genes (ACT, CHS-1, GAPDH, ITS, and TUB2), four specific genes (ApMat, CAL, and GS), and one additional specific gene (APN2) were used in this study, and four species in this study were separated from the C. gloeosporioides species complex. The combined phylogenetic tree was consistent with trees presented in other studies [61,[70][71][72]. ...
European hornbeam (Carpinus betulus L.) is widely planted in landscaping. In October 2021 and August 2022, leaf spot was observed on C. betulus in Xuzhou, Jiangsu Province, China. To identify the causal agent of anthracnose disease on C. betulus, 23 isolates were obtained from the symptomatic leaves. Based on ITS sequences and colony morphology, these isolates were divided into four Colletotrichum groups. Koch’s postulates of four Colletotrichum species showed similar symptoms observed in the field. Combining the morphological characteristics and multi-gene phylogenetic analysis of the concatenated sequences of the internal transcribed spacer (ITS) gene, Apn2-Mat1-2 intergenic spacer (ApMat) gene, the calmodulin (CAL) gene, glyceraldehyde3-phosphate dehydrogenase (GAPDH) gene, Glutamine synthetase (GS) gene, and beta-tubulin 2 (TUB2) genes, the four Colletotrichum groups were identified as C. gloeosporioides, C. fructicola, C. aenigma, and C. siamense. This study is the first report of four Colletotrichum species causing leaf spot on European hornbeam in China, and it provides clear pathogen information for the further evaluation of the disease control strategies.
Colletotrichum, a genus within the phylum Ascomycota (Fungi) and family Glomerellaceae are important plant pathogens globally. In this paper, we detail four Colletotrichum species found in mangrove ecosystems. Two new species, Colletotrichum rhizophorae and C. thailandica, and a new host record for Colletotrichum fructicola were identified in Thailand. Colletotrichum tropicale was collected from Taiwan's mangroves and is a new record for Rhizophora mucronata. These identifications were established through a combination of molecular analysis and morphological characteristics. This expanded dataset for Colletotrichum enhances our understanding of the genetic diversity within this genus and its associations with mangrove ecosystems. The findings outlined herein provide data on our exploration of mangrove pathogens in Asia.
