RESUMEN

Walnut (Juglans regia L.) is cultivated extensively in China for its substantial economic potential as a woody oil species. However, many diseases caused by Diaporthe greatly affect the health of Juglans regia trees. The present study revealed the presence of Diaporthe species from Juglans regia. A total of six species of Diaporthe were isolated from twigs of Juglans regia in three provinces in China, including two known species (Diaporthe gammata and D. tibetensis) and four novel species (D. chaotianensis, D. olivacea, D. shangluoensis and D. shangrilaensis). Phylogenetic relationships of the new species were determined by multilocus phylogenetic analyses based on partial sequences of the internal transcribed spacer (ITS) region, calmodulin (cal) gene, histone H3 (his3) gene, translation elongation factor 1-α (tef1-α) gene and ß-tubulin (tub2) gene. Pathogenicity tests indicated that all Diaporthe species obtained in this study were confirmed as pathogens of Juglans regia. This study deepens the understanding of species associated with several disease symptoms in Juglans regia and provides useful information for effective disease control.

RESUMEN

Cytospora (Cytosporaceae, Diaporthales) is a fungal genus that usually inhabits plants as endophytes, saprobes, as well as pathogens. Species of this genus are characterized by possessing allantoid hyaline conidia and ascospores. Samples with typical Cytospora canker symptoms on Prunus davidiana, P. padus and Salix sp. were collected in Tibet and Xinjiang, China. Species were identified using both morphological and molecular approaches of combined loci of internal transcribed spacer region rDNA (ITS), the partial actin (act) region, RNA polymerase II second largest subunit (rpb2), the translation elongation factor 1-alpha (tef1) gene and the partial be-ta-tubulin (tub2) gene. Six isolates in the present study formed three distinct clades from previously known species. Cytospora hejingensis sp. nov. from Salix sp., C. jilongensis sp. nov. from P. davidiana and C. kunsensis from P. padus were proposed herein. The current study improves the understanding of species concept in Cytospora.

RESUMEN

Members of Cytospora include saprobes, endophytes and important plant pathogens, which are widely distributed on various wood hosts and have a wide global distribution. In this study, the species definitions were conducted, based on multigene phylogeny (ITS, act, rpb2, tef1-α and tub2 genes) and comparisons of morphological characters. A total of 22 representative isolates obtained from 21 specimens in Fengtai District of Beijing City were identified as seven species of Cytospora, including four known species (C.albodisca, C.ailanthicola, C.euonymina, C.haidianensis) and three novel species (C.fengtaiensis, C.pinea, C.sorbariae). The results provide an understanding of the taxonomy of Cytospora species associated with canker and dieback diseases in Fengtai District, Beijing, China.

RESUMEN

Four unprecedented polyketides named isoprenylisobenzofuran B (2), isoprenylisobenzofuran C1/C2 (3), diaporisoindole F1/F2 (4), and isochromophilonol A1/A2 (7) were isolated from ethyl acetate extracts of the newly described endophytic fungus Diaporthe africana. Additionally, the previously reported cyclic depsipeptide eucalactam B (1) was also identified, along with the known compounds diaporisoindole A/B (5), tenellone B (6) and beauvericin (8). The taxonomic identification of the fungus was accomplished using a polyphasic approach combining multi-gene phylogenetic analysis and microscopic morphological characters. The structures 1-8 were determined by a detailed analysis of their spectral data, namely high-resolution electrospray ionization mass spectrometry (HR-ESIMS), 1D/2D nuclear magnetic resonance (NMR) spectroscopy, as well as electronic circular dichroism (ECD) spectra. In addition, chemical methods such as Marfey's analysis were also employed to determine the stereochemistry in compound 1. All the compounds obtained were evaluated for antimicrobial and in vitro cytotoxic properties. Compounds 3-8 were active against certain fungi and Gram-positive bacteria with MIC values of 8.3 to 66.6 µg/mL. In addition, 3-5 displayed cytotoxic effects (22.0 ≤ IC50 ≤ 59.2 µM) against KB3.1 and L929 cell lines, whereas compounds 6-8 inhibited the growth of seven mammalian cancer cell lines with IC50 ranging from 17.7 to 49.5 µM (6), 0.9 to 12.9 µM (7) and 1.9 to 4.3 µM (8).

RESUMEN

The genus Diaporthe (Diaporthaceae, Diaporthales) comprises endophytes, pathogens and saprophytes, inhabiting a wide range of woody hosts and resulting in serious canker disease. To determine the diversity of Diaporthe species associated with canker disease of host plants in Beijing, China, a total of 35 representative strains were isolated from 18 host genera. Three novel species (D.changpingensis, D.diospyrina and D.ulmina) and four known species (D.corylicola, D.donglingensis, D.eres and D.rostrata) were identified, based on morphological comparison and phylogenetic analyses using partial ITS, cal, his3, tef1-α and tub2 loci. These results provide an understanding of the taxonomy of Diaporthe species associated with canker diseases in Beijing, China.

RESUMEN

The EFSA Plant Health Panel performed a pest categorisation of Coniella granati, a clearly defined fungus of the Order Diaporthales and the family Schizoparmaceae, described for the first time in 1876 as Phoma granatii and later named as Pilidiella granati. The pathogen mainly affects Punica granatum (pomegranate) and Rosa spp. (rose), causing fruit rot, shoot blight and cankers on crown and branches. The pathogen is present in North America, South America, as well as in Asia, Africa, Oceania and Eastern Europe and has also been reported in the EU (Greece, Hungary, Italy and Spain), where it is widespread in the major pomegranate growing areas. Coniella granati is not included in Commission Implementing Regulation (EU) 2019/2072 and there are no interceptions in the EU. This pest categorisation focused on those hosts for which the pathogen was detected and formally identified in natural conditions. Plants for planting, fresh fruits and as well as soil and other plant growing media are the main pathways for the further entry of the pathogen into the EU. Host availability and climate suitability factors occurring in parts of the EU are favourable for the further establishment of the pathogen. In the area of its present distribution, including Italy and Spain, the pathogen has a direct impact in pomegranate orchards as well as during post-harvest storage. Phytosanitary measures are available to prevent the further introduction and spread of the pathogen into the EU. Coniella granati does not satisfy the criteria that are within the remit of EFSA to assess for this species to be regarded as potential Union quarantine pest as it is present in several EU MSs.

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Poplar is widely cultivated in China because of its strong ecological adaptability, fast growth, easy reproduction, and short rotation period. However, it suffers from severe threat from canker disease caused by Cytospora species. The present study revealed the presence of Cytospora species from Populus in China. A total of six species of Cytospora were isolated from Populus in six provinces in China, including five known species (C. ailanthicola, C. chrysosperma, C. donglingensis, C. paratranslucens, and C. sophoriopsis) and one novel species (C. populi) based on morphological and phylogenetic analyses of ITS, act, rpb2, tef1-α, and tub2 gene sequences. Cytospora ailanthicola, C. chrysosperma, C. paratranslucens, and C. sophoriopsis are confirmed as pathogens by pathogenicity tests of which C. paratranslucens showed the strongest virulence, followed by C. ailanthicola, C. chrysosperma, and C. sophoriopsis. The mycelial growth rates of isolates from the six species had 22.5 to 27°C as the optimum temperatures, and the optimum pH values were 5.9 to 7.1. The effectiveness of six carbon sources on the mycelial growth showed that colonies grew the fastest in the presence of fructose and grew the slowest using xylose. This study represents a significant evaluation of Cytospora causing poplar canker disease in China.

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RESUMEN

The species of Tubakia (Tubakiaceae, Diaporthales, Sordariomycetes) have often been reported as endophytes and pathogens on woody plants. During the investigation of Tubakia species from Fagaceae trees in China, 46 isolates were obtained from diseased leaves and seeds. The characterization of these isolates was based on the observation of morphological characters, the effect of temperature on mycelial growth rate, as well as the combined genes of ITS, tef1 and tub2. As a result, six species were identified: Tubakia americana, T. cyclobalanopsidis sp. nov., T. dryinoides, T. koreana, T. paradryinoides and T. quercicola sp. nov. Among these, T. koreana and T. paradryinoides were firstly discovered in China. Pathogenicity tests were conducted using the conidial suspension on young, excised leaves for these six species, which showed that they were mildly pathogenic to four Fagacece hosts: C. mollissima, Q. acutissima, Q. aliena var. acutiserrata and Q. variabilis.

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Diaporthe species are endophytes, pathogens, and saprobes with a wide host range worldwide. However, little is known about endophytic Diaporthe species associated with Morinda officinalis. In the present study, 48 endophytic Diaporthe isolates were obtained from cultivated M. officinalis in Deqing, Guangdong Province, China. The nuclear ribosomal internal transcribed spacer (ITS), partial sequences of translation elongation factor 1-α (tef1-α), partial calmodulin (cal), histone H3 (his), and Beta-tubulin (ß-tubulin) gene regions were sequenced and employed to construct phylogenetic trees. Based on morphology and combined multigene phylogeny, 12 Diaporthe species were identified, including five new species of Diaporthe longiconidialis, D. megabiguttulata, D. morindendophytica, D. morindae, and D. zhaoqingensis. This is the first report of Diaporthe chongqingensis, D. guangxiensis, D. heliconiae, D. siamensis, D. unshiuensis, and D. xishuangbanica on M. officinalis. This study provides the first intensive study of endophytic Diaporthe species on M. officinalis in China. These results will improve the current knowledge of Diaporthe species associated with this traditional medicinal plant. Furthermore, results from this study will help to understand the potential pathogens and biocontrol agents from M. officinalis and to develop a disease management platform.

RESUMEN

Species of Cytospora are considered important plant pathogens of a wide range of plant hosts, especially Salicaceae plants. Salix (Salicaceae, Malpighiales) has been widely cultivated in China because of its strong ecological adaptability, fast growth, and easy reproduction. In this study, a total of eight species of Cytospora were discovered on Salix in China, including C. ailanthicola, C. alba, C. chrysosperma, C. gigaspora, C. nivea, C. paracinnamomea, C. rostrata, and C. sophoriopsis. Among them, C. alba and C. paracinnamomea were identified as novel species based on morphology and phylogenetic analyses of ITS, act, rpb2, tef1-α, and tub2 gene sequences and were confirmed as pathogens of willow canker disease by pathogenicity tests. The mycelial growth rates of strains from these two novel species (C. alba and C. paracinnamomea) had optimum temperatures of 21 to 22 °C and an optimum pH value of 5 to 6. The effectiveness of six carbon sources on the mycelial growth showed that fructose and maltose had the highest influence. Cytospora species richness was significantly positively correlated with dry and wet areas. This study represents a significant evaluation of Cytospora associated with willow canker disease in China and provides a theoretical basis for predicting the potential risk of willow canker disease.

RESUMEN

Hazelnut (Corylus heterophylla Fisch.) is an important nut crop in China but has been declining owing to the destructive effects of fungal branch canker and dieback. The identification and management of these pathogens are difficult because of the lack of attention to branch canker, insufficient understanding of phylogenetic, and overlapping morphological characteristics of the pathogens. In total, 51 strains were isolated from Chinese wild hazelnut in this study, and three species of Cytospora and two of Diaporthe were identified through morphological observation and multi-locus phylogenetic analyses (ITS, act, rpb2, tef1-α, and tub2 for Cytospora; ITS, cal, his3, tef1-α, and tub2 for Diaporthe). Three new species, Cytospora corylina, C. curvispora, and Diaporthe corylicola, and two known species, Cytospora leucostoma and Diaporthe eres, grew at 5-30°C and a pH of 3.0-11.0, with optimum growth at approximately 25°C and pH 4.0-7.0. Additionally, the effects of six carbon sources on mycelial growth were investigated. This study explored the main pathogenic fungi species of Corylus heterophylla, completed the corresponding database of pathogenic fungi information, and clarified their biological characteristics. Moreover, the results of this study provided a theoretical basis for Corylus heterophylla disease management and prevention in China.

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RESUMEN

Melanconis-like fungi are distributed in several families of Diaporthales, mainly Juglanconidaceae, Melanconidaceae, Melanconiellaceae and Pseudomelanconidaceae. A new Melanconis-like genus of Pseudomelanconidaceae was discovered on branches of Chinese chestnut (Castanea mollissima) in southern China, which was confirmed by both morphology and phylogenetic analysis of combined ITS, LSU, tef1a and rpb2 sequences. The new genus Micromelanconis is characterized by two types of conidia from natural substrate and manual media of PDA, respectively. Conidia from Chinese chestnut branches are pale brown, ellipsoid, multiguttulate, aseptate with hyaline sheath. While conidia from PDA plates are pale brown, long dumbbell-shaped, narrow at the middle and wide at both ends, multiguttulate, aseptate, and also with hyaline sheath. All Pseudomelanconidaceae species were only reported on tree branches in China until now. More interesting taxa may be discovered if detailed surveys on tree-inhabiting fungi are carried out in East Asia in the future.

RESUMEN

Species of Diaporthe have often been reported as plant pathogens, endophytes or saprobes, commonly isolated from a wide range of plant hosts. Sixteen strains isolated from species of ten host genera in Yunnan Province, China, represented three new species of Diaporthe, D. chrysalidocarpi, D. machili and D. pometiae as well as five known species D. arecae, D. hongkongensis, D. middletonii, D. osmanthi and D. pandanicola. Morphological comparisons with known species and DNA-based phylogenies based on the analysis of a multigene (ITS, TUB, TEF, CAL and HIS) dataset support the establishment of the new species. This study reveals that a high species diversity of Diaporthe with wide host ranges occur in tropical rainforest in Yunnan Province, China.

RESUMEN

Diaporthe species have often been reported as plant pathogens, endophytes and saprophytes, commonly isolated from a wide range of infected plant hosts. In the present study, twenty strains obtained from leaf spots of twelve host plants in Yunnan Province of China were isolated. Based on a combination of morphology, culture characteristics and multilocus sequence analysis of the rDNA internal transcribed spacer region (ITS), translation elongation factor 1-α (TEF), ß-tubulin (TUB), calmodulin (CAL), and histone (HIS) genes, these strains were identified as eight new species: Diaporthe camelliae-sinensis, D. grandiflori, D. heliconiae, D. heterostemmatis, D. litchii, D. lutescens, D. melastomatis, D. pungensis and two previously described species, D. subclavata and D. tectonendophytica. This study showed high species diversity of Diaporthe in tropical rain forests and its hosts in south-western China.

RESUMEN

Two Castanea plant species, C. henryi and C. mollissima, are cultivated in China to produce chestnut crops. Leaf spot diseases commonly occur in Castanea plantations, however, little is known about the fungal species associated with chestnut leaf spots. In this study, leaf samples of C. henryi and C. mollissima were collected from Beijing, Guizhou, Hunan, Sichuan and Yunnan Provinces, and leaf-inhabiting fungi were identified based on morphology and phylogeny. As a result, twenty-six fungal species were confirmed, including one new family, one new genus, and five new species. The new taxa are Pyrisporaceae fam. nov., Pyrispora gen. nov., Aureobasidium castaneae sp. nov., Discosia castaneae sp. nov., Monochaetia castaneae sp. nov., Neopestalotiopsis sichuanensis sp. nov. and Pyrispora castaneae sp. nov.

RESUMEN

BACKGROUND: Sonneratia apetala Francis Buchanan-Hamilton (Sonneratiaceae, Myrtales), is a woody species with high adaptability and seed production capacity. S. apetala is widely cultivated worldwide as the main species for mangrove construction. However, the study of diseases affecting S. apetala is limitted, with only a few fungal pathogens being recorded. Cryphonectriaceae (Diaporthales) species are the main pathogens of plants. They can cause canker diseases to several trees and thereby seriously threaten the health of the hosts. These pathogens include Cryphonectria parasitica (Cryphonectriaceae) causing chestnut blight on Castanea (Rigling and Prospero 2017) and Cytospora chrysosperma (Cytosporaceae) causing polar and willow canker to Populus and Salix (Wang et al. 2015) . Therefore, the timely detection of of Cryphonectriaceae canker pathogens on S. apetala is extremely important for protecting the mangrove forests. NEW INFORMATION: Two diaporthalean fungi, Celoporthe guangdongensis and Cytospora rhizophorae have been reported for the first time to cause canker on the branches of S. apetala. C. guangdongensis is significantly pathogenic and C. rhizophorae is saprophytic on S. apetala.

RESUMEN

Ophiognomonia clavigignenti-juglandacearum (Oc-j) is a plant pathogenic fungus that causes canker and branch dieback diseases in the hardwood tree butternut, Juglans cinerea. Oc-j is a member of the order of Diaporthales, which includes many other plant pathogenic species, several of which also infect hardwood tree species. In this study, we sequenced the genome of Oc-j and achieved a high-quality assembly and delineated its phylogeny within the Diaporthales order using a genome-wide multi-gene approach. We also further examined multiple gene families that might be involved in plant pathogenicity and degradation of complex biomass, which are relevant to a pathogenic life-style in a tree host. We found that the Oc-j genome contains a greater number of genes in these gene families compared to other species in the Diaporthales. These gene families include secreted CAZymes, kinases, cytochrome P450, efflux pumps, and secondary metabolism gene clusters. The large numbers of these genes provide Oc-j with an arsenal to cope with the specific ecological niche as a pathogen of the butternut tree.

RESUMEN

Cytospora canker is a destructive disease of numerous hosts and causes serious economic losses with a worldwide distribution. Identification of Cytospora species is difficult due to insufficient phylogenetic understanding and overlapped morphological characteristics. In this study, we provide an assessment of 23 Cytospora spp., which covered nine genera of Rosaceae, and focus on 13 species associated with symptomatic branch or twig canker and dieback disease in China. Through morphological observation and multilocus phylogeny of internal transcribed spacer (ITS), large nuclear ribosomal RNA subunit (LSU), actin (act), RNA polymerase II subunit (rpb2), translation elongation factor 1-α (tef1-α), and beta-tubulin (tub2) gene regions, the results indicate 13 distinct lineages with high branch support. These include 10 new Cytospora species, i.e., C. cinnamomea, C. cotoneastricola, C. mali-spectabilis, C. ochracea, C. olivacea, C. pruni-mume, C. rosicola, C. sorbina, C. tibetensis, and C. xinjiangensis and three known taxa including Cytospora erumpens, C. leucostoma, and C. parasitica. This study provides an initial understanding of the taxonomy of Cytospora associated with canker and dieback disease of Rosaceae in China.

RESUMEN

Based on molecular phylogenetic and morphological evidence, the new genus Linosporopsis (Xylariales) is established for several species previously classified within Linospora (Diaporthales). Fresh collections of Linospora ischnotheca from dead overwintered leaves of Fagus sylvatica and of L. ochracea from dead overwintered leaves of Malus domestica, Pyrus communis, and Sorbus intermedia were isolated in pure culture, and molecular phylogenetic analyses of a multi-locus matrix of partial nuITS-LSU rDNA, RPB2 and TUB2 sequences as well as morphological investigations revealed that both species are unrelated to the diaporthalean genus Linospora, but belong to Xylariaceae sensu stricto. The new combinations Linosporopsis ischnotheca and L. ochracea are proposed, the species are described and illustrated, and their basionyms lecto- and epitypified. Linospora faginea is synonymized with L. ischnotheca. Based on similar morphology and ecology, Linospora carpini and Linospora magnagutiana from dead leaves of Carpinus betulus and Sorbus torminalis, respectively, are also combined in Linosporopsis. The four accepted species of Linosporopsis are illustrated, a key to species is provided and their ecology is discussed.

RESUMEN

Chinese chestnut (Castanea mollissima) is an important crop tree species in China. In the present study, Cytospora specimens were collected from Chinese chestnut trees and identified using molecular data of combined ITS, LSU, ACT and RPB2 loci, as well as morphological features. As a result, two new Cytospora species and four new host records were confirmed, viz. C. kuanchengensis sp. nov., C. xinglongensis sp. nov., C. ceratospermopsis, C. leucostoma, C. myrtagena and C. schulzeri.