Variation in Botryosphaeriaceae from Eucalyptus plantations in YunNan Province in southwestern China across a climatic gradient

ABSTRACT The Botryosphaeriaceae accommodates many important pathogens of woody plants, including Eucalyptus. Recently, Botryosphaeriaceae were isolated from diseased plant parts from surveys of Eucalyptus plantations in the YunNan Province, China. The aims of this study were to identify these Botryosphaeriaceae isolates and to evaluate their pathogenicity to Eucalyptus. A total of 166 isolates of Botryosphaeriaceae were obtained from six regions in the YunNan Province, of which 76 were from Eucalyptus urophylla × E. grandis hybrids, 49 from E. globulus trees, and 41 isolates were from other unknown Eucalyptus species or hybrids. Isolates were identified by comparing DNA sequences of the internal transcribed spacer ribosomal RNA locus (ITS), partial translation elongation factor 1-alpha (tef1), β-tubulin 2 (tub2) and DNA-directed RNA polymerase II subunit (rpb2) genes, and combined with their morphological characteristics. Eleven species were identified, including Botryosphaeria fusispora, B. wangensis, Lasiodiplodia pseudotheobromae, Neofusicoccum kwambonambiense, N. parvum, and six novel species described as B. puerensis, N. dianense, N. magniconidium, N. ningerense, N. parviconidium and N. yunnanense. The dominant species across the regions were N. yunnanense, N. parvum and B. wangensis, representing 31.3, 25.3 and 19.9% of the total isolates, respectively. Species diversity and composition changed across the different climatic zones, despite their relatively close geographic proximity and the fact that some of the species have a global distribution. All the Botryosphaeriaceae species were pathogenic to one-year-old plants of an E. urophylla × E. grandis clone and E. globulus seed-derived plants, but showed significant inter- and intra-species variation in aggressiveness amongst isolates. The study provides a foundation for monitoring and management of Botryosphaeriaceae through selection and breeding of Eucalyptus in the YunNan Province of southwestern China.

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Redefining genera of cereal pathogens: Oculimacula, Rhynchosporium and Spermospora

Fungal Systematics and Evolution ◽

10.3114/fuse.2021.07.04 ◽

2020 ◽

Author(s):

P.W. Crous ◽

U. Braun ◽

B.A. McDonald ◽

C.L. Lennox ◽

J. Edwards ◽

...

Keyword(s):

Rna Polymerase Ii ◽

Dna Sequences ◽

Large Subunit ◽

Elongation Factor ◽

Morphological Characteristics ◽

Minor Importance ◽

Ammophila Arenaria ◽

Translation Elongation ◽

Elongation Factor 1 Alpha ◽

Three New Species

The taxonomy of Oculimacula, Rhynchosporium and Spermospora is re-evaluated, along with that of phylogenetically related genera. Isolates are identified using comparisons of DNA sequences of the internal transcribed spacer ribosomal RNA locus (ITS), partial translation elongation factor 1-alpha (tef1), actin (act), DNA-directed RNA polymerase II largest (rpb1) and second largest subunit (rpb2) genes, and the nuclear ribosomal large subunit (LSU), combined with their morphological characteristics. Oculimacula is restricted to two species, O. acuformis and O. yallundae, with O. aestiva placed in Cyphellophora, and O. anguioides accommodated in a new genus, Helgardiomyces. Rhynchosporium s. str. is restricted to species with 1-septate conidia and hooked apical beaks, while Rhynchobrunnera is introduced for species with 1–3-septate, straight conidia, lacking any apical beak. Rhynchosporium graminicola is proposed to replace the name R. commune applied to the barley scald pathogen based on nomenclatural priority. Spermospora is shown to be paraphyletic, representing Spermospora (type: S. subulata), with three new species, S. arrhenatheri, S. loliiphila and S. zeae, and Neospermospora gen. nov. (type: N. avenae). Ypsilina (type: Y. graminea), is shown to be monophyletic, but appears to be of minor importance on cereals. Finally, Vanderaaea gen. nov. (type: V. ammophilae), is introduced as a new coelomycetous fungus occurring on dead leaves of Ammophila arenaria.

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Species of Botryosphaeriaceae associated with citrus branch diseases in China

Persoonia - Molecular Phylogeny and Evolution of Fungi ◽

10.3767/persoonia.2021.47.03 ◽

2021 ◽

Author(s):

X.E. Xiao ◽

W. Wang ◽

P.W. Crous ◽

H.K. Wang ◽

C. Jiao ◽

...

Keyword(s):

Rna Polymerase Ii ◽

Dna Sequences ◽

Fungal Pathogens ◽

Elongation Factor ◽

Morphological Characteristics ◽

Control Measures ◽

Botryosphaeria Dothidea ◽

Internal Transcribed Spacer Region

Citrus is an important and widely cultivated fruit crop in South China. Although the species of fungal diseases of leaves and fruits have been extensively studied, the causal organisms of branch diseases remain poorly known in China. Species of Botryosphaeriaceae are known as important fungal pathogens causing branch diseases on citrus in the USA and Europe. To determine the diversity of Botryosphaeriaceae species associated with citrus branch diseases in China, surveys were conducted in the major citrus-producing areas from 2017 to 2020. Diseased tissues were collected from twigs, branches and trunks with a range of symptoms including cankers, cracking, dieback and gummosis. Based on morphological characteristics and phylogenetic comparison of the DNA sequences of the internal transcribed spacer region (ITS), the translation elongation factor 1-alpha gene (tef1), the β-tubulin gene (tub2) and the DNA-directed RNA polymerase II second largest subunit (rpb2), 111 isolates from nine provinces were identified as 18 species of Botryosphaeriaceae, including Botryosphaeria dothidea, B. fabicerciana, Diplodia seriata, Dothiorella alpina, Do. plurivora, Lasiodiplodia citricola, L. iraniensis, L. microconidia, L. pseudotheobromae, L. theobromae, Neodeightonia subglobosa, Neofusicoccum parvum, and six previously undescribed species, namely Do. citrimurcotticola, L. guilinensis, L. huangyanensis, L. linhaiensis, L. ponkanicola and Sphaeropsis linhaiensis spp. nov. Botryosphaeria dothidea (28.8 %) was the most abundant species, followed by L. pseudotheobromae (23.4 %), which was the most widely distributed species on citrus, occurring in six of the nine provinces sampled. Pathogenicity tests indicated that all 18 species of Botryosphaeriaceae obtained from diseased citrus tissues in this study were pathogenic to the tested Citrus reticulata shoots in vitro, while not all species are pathogenic to the tested Cocktail grapefruit (C. paradisi × C. reticulata) shoots in vivo. In addition, Lasiodiplodia was the most aggressive genus both in vitro and in vivo. This is the first study to identify Botryosphaeriaceae species related to citrus branch diseases in China and the results provide a theoretical basis for the implementation of prevention and control measures.

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Amanita submelleialba sp. nov. in section Amanita from northern Thailand

Phytotaxa ◽

10.11646/phytotaxa.513.2.4 ◽

2021 ◽

Vol 513 (2) ◽

pp. 129-140

Author(s):

YUAN S. LIU ◽

JIAN-KUI LIU ◽

PETER E. MORTIMER ◽

SAISAMORN LUMYONG

Keyword(s):

Rna Polymerase Ii ◽

Phylogenetic Analyses ◽

Line Drawing ◽

Elongation Factor ◽

Morphological Characteristics ◽

Nuclear Rdna ◽

Internal Transcribed Spacer Region ◽

Northern Thailand ◽

Extant Species ◽

Distinct Lineage

Amanita submelleialba sp. nov. in section Amanita, is described from northern Thailand based on both multi-gene phylogenetic analysis and morphological evidences. It is characterized by having small to medium-sized basidiomata; a yellow to yellowish pale pileus covering pyramidal to subconical, white to yellow white volval remnants; globose stipe base covered conical, white to yellow white volval remnants; fugacious subapical annulus; and absent clamps. Multi-gene phylogenetic analyses based on partial nuclear rDNA internal transcribed spacer region (ITS), partial nuclear rDNA larger subunit region (nrLSU), RNA polymerase II second largest subunit (RPB2), partial translation elongation factor 1-alpha (TEF1-α) and beta-tubulin gene (TUB) indicated that A. submelleialba clustered together with A. elata and A. mira, but represented as a distinct lineage from other extant species in section Amanita. The detailed morphological characteristics, line-drawing illustration and comparisons with morphologically similar taxa are provided.

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First Report of Fusarium oxysporum f. sp. lycopersici Race 3 Causing Fusarium Wilt on Tomato in Korea

Plant Disease ◽

10.1094/pdis-01-13-0073-pdn ◽

2013 ◽

Vol 97 (10) ◽

pp. 1377-1377 ◽

Cited By ~ 4

Author(s):

H.-W. Choi ◽

S. K. Hong ◽

Y. K. Lee ◽

H. S. Shim

Keyword(s):

Fusarium Wilt ◽

Dna Sequences ◽

Vascular Tissue ◽

Elongation Factor ◽

Morphological Characteristics ◽

Spore Suspension ◽

Vascular Bundles ◽

Laboratory Manual ◽

First Report ◽

Blastn Analysis

In July 2010, fusarium wilt symptoms of tomato (Lycopersicon esculentum Mill.) plants were found in two commercial greenhouses in the Damyang area of Korea. Approximately 1% of 7,000 to 8,000 tomato plants were wilted and chlorotic in each greenhouse. The vascular tissue was usually dark brown and the discoloration extended to the apex. Fragments (each 5 × 5 mm) of the symptomatic tissue were surface-sterilized with 1% NaOCl for 1 min, then rinsed twice in sterilized distilled water (SDW). The tissue pieces were placed on water agar and incubated at 25°C for 4 to 6 days. Nine Fusarium isolates were obtained from four diseased plants, of which three isolates were identified as F. oxysporum based on morphological characteristics on carnation leaf agar medium and DNA sequences of the translation elongation factor 1-alpha (EF-1α) gene (2). Macroconidia were mostly 3- to 5-septate, slightly curved, and 28 to 53 × 2.8 to 5.2 μm. Microconidia were abundant, borne in false heads or short monophialides, generally single-celled, oval to kidney shaped, and 5 to 23 × 3 to 5 μm. Chlamydospores were single or in short chains. The EF-1α gene was amplified from three isolates by PCR assay using ef1 and ef2 primers (3), and the amplification products were sequenced. The nucleotide sequences obtained were deposited in GenBank (Accession Nos. KC491844, KC491845, and KC491846). BLASTn analysis showed 99% homology with the EF-1α sequence of F. oxysporum f. sp. lycopersici MN-24 (HM057331). Pathogenicity tests and race determination were conducted using root-dip inoculation (4) on seedlings of tomato differential cultivars: Ponderosa (susceptible to all races), Momotaro (resistant to race 1), Walter (resistant to races 1 and 2), and I3R-1 (resistant to all races). A spore suspension was prepared by flooding 5-day-old cultures on potato dextrose agar with SDW. Plants at the first true-leaf stage were inoculated by dipping the roots in the spore suspension (1 × 106 conidia/ml) for 10 min. Inoculated plants were transplanted into pots containing sterilized soil, and maintained in the greenhouse at 25/20°C (12/12 h). Twenty-four seedlings of each cultivar were arranged into three replications. An equal number of plants of each cultivar dipped in water were used as control treatments. Disease reaction was evaluated 3 weeks after inoculation, using a disease index on a scale of 0 to 4 (0 = no symptoms, 1 = slightly swollen and/or bent hypocotyl, 2 = one or two brown vascular bundles in the hypocotyl, 3 = at least two brown vascular bundles and growth distortion, 4 = all vascular bundles brown and the plant either dead or very small and wilted). All isolates caused symptoms of fusarium wilt on all cultivars except I3R-1, indicating that the isolates were race 3. The pathogen was reisolated from the discolored vascular tissue of symptomatic plants. Control plants remained asymptomatic, and the pathogen was not reisolated from the vascular tissue. Fusarium wilt of tomato caused by isolates of F. oxysporum f. sp. lycopersici races 1 and 2 has been reported previously; however, race 3 has not been reported in Korea (1). To our knowledge, this is the first report of isolates of F. oxysporum f. sp. lycopersici race 3 on tomato in Korea. References: (1) O. S. Hur et al. Res. Plant Dis. 18:304, 2012 (in Korean). (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (3) K. O'Donnell et al. Proc. Nat. Acad. Sci. 95:2044, 1998. (4) M. Rep et al. Mol. Microbiol. 53:1373, 2004.

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First Report of Fusarium equiseti Causing Fusarium Wilt on Potato (Solanum tuberosum) in China

Plant Disease ◽

10.1094/pdis-02-21-0281-pdn ◽

2021 ◽

Author(s):

Lingxiao Cui ◽

Chengde Yang ◽

Liping Yang ◽

Mengjun Jin ◽

Lijuan Wei

Keyword(s):

Solanum Tuberosum ◽

Rna Polymerase Ii ◽

Fusarium Wilt ◽

Elongation Factor ◽

Morphological Characteristics ◽

Gansu Province ◽

Vascular Bundles ◽

First Report ◽

Potato Plants ◽

Pathogenicity Tests

Potato (Solanum tuberosum) is one of the most economically important crops in China, containing carbohydrates, protein, fiber, numerous vitamins and minerals, and is a heart healthy food (Raidl, 2020). Potato infected by Fusarium spp. exhibits quality and yield decline, and even death. In infected plants, the upper leaves exhibit chlorosis, the lower leaves wither and the vascular bundles of stems and tubers turn yellow, and then tan to brown. In August 2018, symptomatic potato stems and roots were collected from Zhangye city, Gansu province, China. Diseased stem tissues were surface sterilized with 75% alcohol for 30 s, and then rinsed in sterile water. The tissue pieces were placed on potato dextrose agar (PDA) and incubated at 25°C in darkness. Fusarium-like colonies were consistently isolated and three monoconidial isolates were obtained. Isolate 3SMJ-2 was selected as a representative for morphological characterization, molecular analysis, and pathogenicity tests. 3SMJ-2 was inoculated in PDA liquid medium, grown on a shaker for 7 days at 25℃ to obtain a mix suspension of hypha fragments and spores (107 spores/mL). Healthy potato plants, named “Xin Daping” and were planted in pots (17 cm diameter by 12 cm) filled with 2L of sterile soil per pot. After 8 weeks, the plants were inoculated with the inoculum or distilled water. Then they were incubated in growth chambers at 25°C under a 12-h/12-h day/night potato period with 90% relative humidity for 24 h. For each treatment, 3 pots were inoculated. After 50 days, 100% of the inoculated potato plants exhibited wilt symptoms similar to those in the field but the control plants were symptomless. A Fusarium identical to strain 3SMJ-2 was re-isolated from symptomatic potato plants to fulfilling Koch’s postulates. Morphological characteristics of the re-isolated strain were identical to the original isolate, which confirmed pathogenicity of strain 3SMJ-2 originally isolated from the potatoes. Colonies of 3SMJ-2 were white with short conidiophores, a few microconidia and sickle-shaped macroconidia (25.2 to 42.9× 3.1 to 4.6 µm) (n = 60) with 4~7 septa, and mostly 5 septa, after cultivated on PDA in an incubator at 25℃ for 14 days. Spherical terminal or intercalary chlamydospores were observed on the mycelium. Strain 3SMJ-2 was identified preliminarily as Fusarium sp. based on morphological characteristics (Leslie et al., 2006). Genomic DNA was extracted from 3SMJ-2 using the OMEGA Fungal DNA kit according to the manufacturer’s protocol. The internal transcribed spacer (ITS), translation elongation factor 1-alpha (TEF) and RNA polymerase II second largest subunit (RPB2) were amplified using ITS1/ITS4 (White et al., 1990), Ef728M/Tef1R (Stępień et al., 2012) and 5F2 /7cR (O'Donnell et al., 2007), respectively. After sequencing by Beijing TSINGKE Biological Technology Co., Ltd., 3 fragments of approximately 519 bp, 587 bp and 1059 bp from the strain 3SMJ-2 were deposited in GenBank as MN420681, MW561963 and MW561964. The ITS, TEF and RPB2 sequences were 100%, 100% and 99.8% identical to those of F.equiseti (KY365589, KF499577, and MH582110). Based on the pathogenicity tests, morphological characteristics and molecular analyses, we identified the strain 3SMJ-2 as F. equiseti, the pathogen causing Fusarium wilt on potato in Zhangye City. Although, F. equiseti has been reported to cause root rot of cowpea (Li et al., 2017) and sugar beet (Cao et al., 2018) in China. To our knowledge, this is the first report confirming F. equiseti causing potato wilt in China. Potato is an economically important crop in Gansu and the occurrence of the new disease caused by F. equiseti on potato needs to be properly managed to reduce yield loss.

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Occurrence and Morpho-Molecular Identification of Botryosphaeriales Species from Guizhou Province, China

Journal of Fungi ◽

10.3390/jof7110893 ◽

2021 ◽

Vol 7 (11) ◽

pp. 893

Author(s):

Asha J. Dissanayake ◽

Ya-Ya Chen ◽

Ratchadawan Cheewangkoon ◽

Jian-Kui Liu

Keyword(s):

Fungal Pathogens ◽

Sequence Data ◽

Phylogenetic Analyses ◽

Large Subunit ◽

Elongation Factor ◽

Morphological Characteristics ◽

Guizhou Province ◽

Southwestern China ◽

Rrna Gene ◽

Large Subunit Rrna

Botryosphaeriales is an important order of diverse fungal pathogens, saprobes, and endophytes distributed worldwide. Recent studies of Botryosphaeriales in China have discovered a broad range of species, some of which have not been formerly described. In this study, 60 saprobic isolates were obtained from decaying woody hosts in southwestern China. The isolates were compared with other species using morphological characteristics, and available DNA sequence data was used to infer phylogenetic analyses based on the internal transcribed spacer (ITS), large subunit rRNA gene (LSU), and translation elongation factor 1-α (tef) loci. Three novel species were illustrated and described as Botryobambusa guizhouensis, Sardiniella elliptica, and Sphaeropsis guizhouensis, which belong to rarely identified genera within Botryosphaeriaceae. Botryobambusa guizhouensis is the second species identified from the respective monotypic genus. The previously known species were identified as Aplosporella hesperidica, Barriopsis tectonae, Botryosphaeria dothidea, Diplodia mutila, Di. neojuniperi, Di. pseudoseriata, Di. sapinea, Di. seriata, Dothiorella sarmentorum, Do. yunnana, Lasiodiplodia pseudotheobromae, Neofusicoccum parvum, Sardiniella celtidis, Sa. guizhouensis, and Sphaeropsis citrigena. The results of this study indicate that numerous species of Botryosphaeriales are yet to be revealed in southwestern China.

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Four new species in the Tremella fibulifera complex (Tremellales, Basidiomycota)

MycoKeys ◽

10.3897/mycokeys.82.63241 ◽

2021 ◽

Vol 82 ◽

pp. 33-56

Author(s):

Long-Fei Fan ◽

Renato Lúcio Mendes Alvarenga ◽

Tatiana Baptista Gibertoni ◽

Fang Wu ◽

Yu-Cheng Dai

Keyword(s):

New Species ◽

Rna Polymerase Ii ◽

Phylogenetic Analyses ◽

Large Subunit ◽

Elongation Factor ◽

Morphological Characteristics ◽

Molecular Data ◽

Small Subunit ◽

Molecular Evidence ◽

Rrna Gene

Samples of species close to Tremella fibulifera from China and Brazil are studied, and T. fibulifera is confirmed as a species complex including nine species. Five known species (T. cheejenii, T. fibulifera s.s., T. “neofibulifera”, T. lloydiae-candidae and T. olens) and four new species (T. australe, T. guangxiensis, T. latispora and T. subfibulifera) in the complex are recognized based on morphological characteristics, molecular evidence, and geographic distribution. Sequences of eight species of the complex were included in the phylogenetic analyses because T. olens lacks molecular data. The phylogenetic analyses were performed by a combined sequence dataset of the internal transcribed spacer (ITS) and the partial nuclear large subunit rDNA (nLSU), and a combined sequence dataset of the ITS, partial nLSU, the small subunit mitochondrial rRNA gene (mtSSU), the translation elongation factor 1-α (TEF1), the largest and second largest subunits of RNA polymerase II (RPB1 and RPB2). The eight species formed eight independent lineages with robust support in phylogenies based on both datasets. Illustrated description of the six species including Tremella fibulifera s.s., T. “neofibulifera” and four new species, and discussions with their related species, are provided. A table of the comparison of the important characteristics of nine species in the T. fibulifera complex and a key to the whitish species in Tremella s.s. are provided.

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First Report of Fusarium succisae Causing Flower Rot on Thread-leaf Coreopsis

Plant Disease ◽

10.1094/pdis-12-13-1205-pdn ◽

2014 ◽

Vol 98 (7) ◽

pp. 1002-1002 ◽

Cited By ~ 2

Author(s):

H.-W. Choi ◽

S. K. Hong ◽

Y. K. Lee ◽

W. G. Kim

Keyword(s):

Dna Sequences ◽

Production Control ◽

Fusarium Species ◽

Elongation Factor ◽

Morphological Characteristics ◽

Spore Suspension ◽

Sugar Solution ◽

Laboratory Manual ◽

First Report ◽

Blastn Analysis

In July 2010, flower rot of thread-leaf coreopsis (Coreopsis verticillata) was found in a garden in the Icheon City, Korea. The disease affected about 20 to 50% of a 100 m2 area. The disease was characterized by the appearance of pinkish mycelia on the stigmata and inflorescences of flowers. In some cases, flowers failed to bloom or turned brown before opening fully. Fragments (each 5 × 5 mm) of the symptomatic tissue were surface-sterilized with 1% NaOCl for 1 min, and then rinsed twice in sterilized distilled water. The tissue pieces were placed on water agar (WA) and incubated at 25°C for 4 to 6 days. Twenty-two isolates of Fusarium species were obtained from the diseased flowers. All isolates were identified as Fusarium succisae based on their morphological characteristics on carnation leaf agar (CLA) medium and DNA sequences of the translation elongation factor 1-alpha gene (1). Macroconidia and sporodochia were sparsely produced on CLA medium. Microconidia were abundant, borne in false heads, oval or allantoid and sometimes pyriform, and measured 4.2 to 13 × 2.2 to 5.4 μm. Chlamydospores were absent. The EF-1α gene was amplified from three isolates by PCR assay and the amplification products were sequenced (2). The nucleotide sequences obtained were deposited in GenBank with accession numbers KF514658, KF514659, and KF514660. BLASTn analysis showed 99% homology with the EF-1α sequence of F. succisae NRRL13613 (GenBank Accession No. AF160291). Pathogenicity tests were conducted with inoculation of flowers on Coreopsis verticillata. Spore suspension was prepared by flooding 7-day-old cultures on potato dextrose agar with sterilized 2% (w/v) sugar solution. When the plants started to have buds, the isolates were inoculated by placing one drop (20 μl) of spore suspension (1 × 106 spores ml−1) into the buds. Fifteen buds of the plants were arranged into three replications. The control was treated with sterilized 2% sugar solution. Inoculated plants were kept in a greenhouse at 25/20°C (12 h/12 h). Three weeks after inoculation, the symptoms were observed on buds with mycelial production. Control plants had no mycelia on buds. F. succisae was re-isolated from the inoculated flowers. To our knowledge, this is the first report of flower rot of thread-leaf coreopsis caused by F. succisae. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (2) K. O'Donnell et al. Proc. Nat. Acad. Sci. 95:2044, 1998.

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Pathogenic, Morphological, and Phylogenetic Characterization of Fusarium solani f. sp. cucurbitae Isolates From Cucurbits in Almería Province, Spain

Plant Disease ◽

10.1094/pdis-09-19-1954-re ◽

2020 ◽

Vol 104 (5) ◽

pp. 1465-1476

Author(s):

Ana Pérez-Hernández ◽

Liliana O. Rocha ◽

Elena Porcel-Rodríguez ◽

Brett A. Summerell ◽

Edward C. Y. Liew ◽

...

Keyword(s):

Rna Polymerase Ii ◽

Fusarium Solani ◽

Elongation Factor ◽

Morphological Characteristics ◽

Differential Susceptibility ◽

Morphological Characterization ◽

Soilborne Pathogens ◽

Phylogenetic Characterization ◽

Phylogenetic Studies ◽

The Individual

Fusarium solani f. sp. cucurbitae (syn. Neocosmosporum cucurbitae) is one of the most devastating soilborne pathogens affecting the production of cucurbits worldwide. Since its first detection in Almería Province in Spain in the spring of 2007, it has become one of the main soilborne pathogens affecting zucchini production. It has also been reported on melon, watermelon, and squash rootstocks in Spain, representing a high risk of dissemination in the area. The objectives of this study were to investigate the incidence and distribution of this disease in southeastern Spain and characterize isolates collected over 5 years. These strains were characterized on the basis of greenhouse aggressiveness assays on a range of cucurbit hosts, morphological characteristics, and elongation factor 1-α and RNA polymerase II second largest subunit phylogenies. All pathogenic isolates were highly aggressive on zucchini plants, causing a high mortality rate a few weeks after inoculation. The rest of the cucurbit hosts showed differential susceptibility to the pathogen, with cucumber being the least susceptible. Plants belonging to other families remained asymptomatic. Morphological characterization revealed the formation of verticilate monophialides and chlamydospores forming long chains, characteristics not described for this forma specialis. Phylogenetic studies of both the individual loci and combined datasets revealed that all pathogenic isolates clustered together with strong monophyletic support, nested within clade 3 in the F. solani species complex.

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Morphological characters and molecular data reveal a new species of Rhodonia (Polyporales, Basidiomycota) from China

Phytotaxa ◽

10.11646/phytotaxa.328.2.8 ◽

2017 ◽

Vol 328 (2) ◽

pp. 175

Author(s):

YUAN YUAN ◽

LU-LU SHEN

Keyword(s):

New Species ◽

Rna Polymerase Ii ◽

Dna Sequences ◽

Large Subunit ◽

Morphological Characteristics ◽

Northwest China ◽

Morphological Characters ◽

Molecular Data ◽

Molecular Evidence ◽

A New Species

A new polypore, Rhodonia tianshanensis, collected from West Tianshan Nature Reserve in Xinjiang Autonomous Region (northwest China), is described and illustrated based on morphological characteristics and molecular evidence. It is characterized by having resupinate basidiomata with an oblique tube layer, fusoid cystidioles in the hymenium, and cylindrical basidiospores. Based on multiple loci DNA sequences including the internal transcribed spacer (ITS), the large subunit (nLSU), and the second subunit of RNA polymerase II (RPB2) regions, our phylogeny strongly supported R. tianshanensis as a new species belonging to the genus Rhodonia.

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