Short Conidiophores Research Articles

Four novel species of Pleurotheciaceae collected from freshwater habitats in Jiangxi Province, China.

During an investigation of fungal diversity from freshwater environments in different regions in Jiangxi Province, China, four interesting species were collected. Morphology coupled with combined gene analysis of an ITS, LSU, SSU, and rpb2 DNA sequence data showed that they belong to the family Pleurotheciaceae. Four new species, Pleurotheciella ganzhouensis, Pla. irregularis, Pla. verrucosa, and Pleurothecium jiangxiense are herein described. Pleurotheciella ganzhouensis is characterized by its capsule-shaped conidia and short conidiophores, while Pla. irregularis has amorphous conidiophores and 3-septate conidia. Pleurotheciella verrucosa has cylindrical or verrucolose conidiogenous cells, 1-septate, narrowly fusiform, meniscus or subclavate conidia. Pleurothecium jiangxiense characterized in having conidiogenous cells with dense cylindrical denticles and short conidiophores. Pleurothecium obovoideum was transferred to Neomonodictys based on phylogenetic evidence. All species are compared with other similar species and comprehensive descriptions, micrographs, and phylogenetic data are provided.

Phylogenetic Insights Reveal New Taxa in Thyridariaceae and Massarinaceae.

Pleosporales is a highly diverse (and the largest) order in Dothideomycetes, and it is widespread in decaying plants in various environments around the world. During a survey of fungal diversity in Sichuan Province, China, specimens of hyphomycetous and Thyridaria-like fungi were collected from dead branches of pine trees and cherry trees. These taxa were initially identified as members of Massarinaceae and Thyridariaceae through morphological examination. Phylogenetic analyses of the Thyridariaceae, combining ITS, SSU, LSU, RPB2, and TEF1 sequence data, indicated a distinct clade sister to Pseudothyridariella and Thyridariella, distinct from any genus in the family. Thus, a new genus, Vaginospora, is proposed to accommodate the type species Vaginospora sichuanensis, which is characterized by semi-immersed globose to oblong ascomata with an ostiolar neck, cylindrical to clavate asci with an ocular chamber, and hyaline to dark brown, fusiform, 3-5-transversely septate ascospores with an inconspicuous mucilaginous sheath. Based on the morphological comparisons and multi-locus phylogenetic analyses (ITS, SSU, LSU, RPB2, and TEF1) of the Massarinaceae, we have identified three collections belonging to the genus Helminthosporium, leading us to propose H. filamentosa sp. nov., H. pini sp. nov., and H. velutinum as a new host record. According to Phylogenetic analysis, H. pini formed an independent clade sister to H. austriacum and H. yunnanense, and H. filamentosa represents the closest sister clade to H. quercinum. Helminthosporium pini is distinct from H. austriacum by the shorter conidiophores and H. yunnanense by the longer and wider conidia. The H. filamentosa differs from H. quercinum in having longer conidiophores and smaller conidia. This study extends our understanding of diversity within Thyridariaceae and Helminthosporium. Our findings underscore the rich biodiversity and potential for discovering novel fungal taxa within these groups.

Helminthosporium paraoligosporum sp. nov., a new ascomycetous fungus from Ontario, Canada

A novel anamorphic ascomycetous fungus, Helminthosporium paraoligosporum (Pleosporales, Ascomycota), isolated from branches of linden trees is described and characterized. The species is morphologically distinct from other Helminthosporium spp. by shorter conidiophores and conidia, and culture characteristics. Phylogenetic analysis of a combined set of ITS and LSU sequence data also supports the establishment of a new species. H. paraoligosporum is clustered with H. caespitosum, H. oligosporum, and H. tiliae. The species in this clade have similar morphological characteristics and host affiliation. In particular, conidiophores of the species (except H. tiliae) can be reduced to elongated conidiogenous cells. H. caespitosum is associated with Betula spp., while the other species in this clade have been collected from Tilia spp. only.

Phyllactinia cornicola, a new species of powdery mildews from Pakistan

A new powdery mildew fungus, Phyllactinia cornicola (Erysiphaceae) infecting dogwood trees is described from Azad Jammu & Kashmir, Pakistan. Identification is based upon morpho‐anatomical features and molecular analysis. This species is characterized by having shorter conidiophores, and smaller chasmothecia, asci and ascospores compared to P. guttata and P. corni. Phylogenetic analysis based on ITS sequences supports its recognition as novel species of Phyllactinia. A comprehensive description, along with photographs and a phylogram to show its exact position, as well as a comparison with closely related taxa is provided.

Alternaria alternata causing Alternaria Leaf Spot of Cucumis melo (Muskmelon) in Pakistan.

In July 2019, leaf spot symptoms were observed on muskmelon (Cucumis melo L.) cv. Jackball-1 plants in an experimental field of 2.02 ha with a disease incidence of 30% (31°26'05.4"N 73°04'30.3"E) at the University of Agriculture, Faisalabad, Pakistan. Early symptoms consisted of small, circular, brown, necrotic spots 1 to 2 mm in size covering 10 to 30% of the leaf blade, which gradually enlarged and developed concentric rings. To identify the causal agent of the disease, a total of 20 symptomatic leaves were collected. Small pieces removed from the margin between healthy and diseased tissues were surface disinfected in 70% ethanol for 2 min, rinsed three times with sterile distilled water, plated on Potato dextrose agar and incubated at 25 ± 2°C with a 12-h photoperiod. Morphological observations were made on 7-day-old single-spore cultures. The colonies initially appeared white and then turned olive-green. All 20 fungal isolates were characterized by small, short-beaked, multicellular conidia. The conidia were ellipsoidal or ovoid and measured 11.5 to 30 μm × 7.5 to 15 μm (n = 50) with longitudinal and transverse septa. Conidia were produced on short conidiophores in chains. The beaks were short (often less than one-third the body length) and conical or cylindrical. These morphological features concur with the description of Alternaria alternata (Fr.) Keissler (Woudenberg et al. 2013). For molecular identification, genomic DNA of four representative isolates (HMSMZA 07, 08, 09, 10) were extracted and PCR amplification of the internal transcribed spacer (ITS)-rDNA, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and translation elongation factor-1 alpha (TEF-1α) gene regions were performed (White et al. 1990, Berbee et al. 1999, Carbone & Kohn, 1999) respectively. The obtained sequences were deposited in GenBank with accession numbers MT253643.1-MT253646.1 (ITS-rDNA), MT318260.1-MT318263.1 (GAPDH), and MT318280.1-MT318283.1 (TEF-1α). BLASTn analysis of HMSMZA 07 sequences showed 100% identity with ITS rDNA (MN615420.1), GAPDH (MK637438.1) and TEF-1α (MN807795.1) sequences of A. alternata. To confirm pathogenicity, 5-6 weeks-old Muskmelon (Cucumis melo L.) cv. Jackball-1 plants (true leaf stage) were sprayed until runoff (1.5 to 2 ml per plant) with A. alternata conidial suspension (106 conidia/ml; obtained from 1 week-old cultures) amended with 0.1% (vol/vol) of Tween 20 using an atomizer in the green house. The experiment included four A. alternata isolates inoculated onto three muskmelon plants per each isolate, whereas control plants (n = 3) were sprayed with sterile distilled water amended with 0.1% Tween 20. The plants were incubated at 25 ± 2°C in a greenhouse and the experiment was conducted twice. After 5 to 7 days post inoculation, necrotic leaf spots were observed on the inoculated plants and A. alternata was reisolated and confirmed by morphological and molecular (ITS) features. No disease was observed on control plants. Previously, A. alternata on muskmelon has been reported in Pakistan (Ahmad et al. 1997), however this study provides a detailed description of disease symptoms, morphological and molecular identity of the causal agent including completion of Koch's postulates. The disease could represent a threat for muskmelon crop in Pakistan due to its increasing cultivation and therefore warrants the need to develop disease management strategies.

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

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.

Genetic Analysis and Pathogenic Characterization of Alternaria tenuissima Induced Fruit Rot of Bitter Gourd

Abstract. Iftikhar S, Anwar W, Akhter A, Ali S, Khan HAA, Khurshid M, Haider MS. 2021. Genetic analysis and pathogenic characterization of Alternaria tenuissima induced fruit rot of bitter gourd. Biodiversitas 22: 617-625. Bitter gourd (Momordica charantia Linn.), belongs to Cucurbitaceae family, is widely cultivated in areas with warm climate. In 2017, fruits of bitter gourd-bearing rot symptoms were observed in the Punjab province of Pakistan. The disease-causing fungal isolate was collected from the diseased fruits on potato dextrose agar (PDA). Microscopic examination revealed short conidiophores arose singly, measuring 79.8- 158.5 μm long and 3.94-7.89 μm thick. The size of conidia varied from 25.7 to 46.45 μm and 8.55-14.39 μm in length and width respectively, which were characteristics of Alternaria spp. To confirm the identity and molecular characterization of the isolate, the internal transcribed spacer (ITS) region, translation elongation factor 1 alpha (TEF1-α), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and RNA polymerase II large subunit 2 (RPB2) genes were amplified. The sequence analysis of amplicons and phylogenetic studies specified the homology of isolated Alternaria spp. with the previously reported A. tenuissima in GeneBank. The pathogenicity tests conducted on the fruits of bitter gourd confirmed the disease development with typical Alternaria induced rot symptoms, thus satisfied Koch's postulate. To our knowledge, this is the first record of A. tenuissima causing fruit rot of bitter gourd in Pakistan.

First Report of Leaf Spot of Salvia farinacea Caused by Alternaria alternata in China

HomePlant DiseaseVol. 104, No. 9First Report of Leaf Spot of Salvia farinacea Caused by Alternaria alternata in China PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Leaf Spot of Salvia farinacea Caused by Alternaria alternata in ChinaJ. J. Ding, X. Gu, X. H. Yang, L. L. Yao, X. D. Gao, M. M. Zhang, and Y. G. LiJ. J. DingJiamusi Branch of Heilongjiang Academy of Agricultural Sciences, Jiamusi 154000, ChinaSearch for more papers by this author, X. GuJiamusi Branch of Heilongjiang Academy of Agricultural Sciences, Jiamusi 154000, ChinaSearch for more papers by this author, X. H. YangJiamusi Branch of Heilongjiang Academy of Agricultural Sciences, Jiamusi 154000, ChinaSearch for more papers by this author, L. L. YaoJiamusi Branch of Heilongjiang Academy of Agricultural Sciences, Jiamusi 154000, ChinaSearch for more papers by this author, X. D. GaoJiamusi Branch of Heilongjiang Academy of Agricultural Sciences, Jiamusi 154000, ChinaSearch for more papers by this author, M. M. ZhangJiamusi Branch of Heilongjiang Academy of Agricultural Sciences, Jiamusi 154000, ChinaSearch for more papers by this author, and Y. G. Li†Corresponding author: Y. G. Li; E-mail Address: neaulyg@126.comhttp://orcid.org/0000-0003-4582-2473Agricultural College, Northeast Agricultural University, Harbin 150030, ChinaSearch for more papers by this author AffiliationsAuthors and Affiliations J. J. Ding1 X. Gu1 X. H. Yang1 L. L. Yao1 X. D. Gao1 M. M. Zhang1 Y. G. Li2 † 1Jiamusi Branch of Heilongjiang Academy of Agricultural Sciences, Jiamusi 154000, China 2Agricultural College, Northeast Agricultural University, Harbin 150030, China Published Online:9 Jul 2020https://doi.org/10.1094/PDIS-02-20-0415-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Salvia farinacea Benth. is a herbaceous perennial plant. In July 2018, a leaf spot disease was observed on S. farinacea at four nurseries in Harbin, China, with approximately 50% of the plants diseased. Disease symptoms were irregular, necrotic spots on leaves (0.5 to 1 mm in diameter). Ten tissue samples from 10 individual plants were surface disinfested in 0.5% NaOCl for 5 min, rinsed three times in sterile distilled water, and cultured on potato dextrose agar (PDA) amended with antibiotics at 26°C. Six similar fungal cultures were isolated and subcultured. Single-conidium isolates were generated with methods reported previously (Leslie and Summerell 2006). Colonies on PDA were olive-green with a white margin, with black pigments and abundant aerial hyphae. Conidia were black to brown, obclavate to obpyriform, with a small beak in long sparsely branched chains on simple short conidiophores, measuring 4.6 to 14.2 μm in width and 8.2 to 30.8 μm in length (n = 50), and had one to four transverse and zero to three longitudinal septa. According to these morphological characteristics, all isolates were identified as a species of Alternaria (Simmons 2007). Genomic DNA was extracted from the mycelium of three representative isolates: XPC1, XPC3, and XPC6. The internal transcribed spacer region (ITS), translation elongation factor 1-α gene (TEF1), and glyceraldehyde 3-phosphate dehydrogenase (GPD) were amplified and sequenced using primers ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and Gpd1/Gpd2 (Woudenberg et al. 2013). The consensus sequences (accession nos. MN733165 for ITS, MN756011 for TEF1, and MT108177 for GPD) were aligned using BLASTn in GenBank and were 100% identical to A. alternata strains ITC20 (accession no. KX987252.1), WCS1-5 (MK791316.1), and YJ1 (KP851968.1), respectively. To confirm pathogenicity of XPC1, XPC3, and XPC6, S. farinacea plants were grown in 15-cm pots containing a commercial potting mix (one plant/pot). At the five- to eight-leaf stage, three healthy plants were inoculated by spraying 50 μl of conidial suspension of the isolates (4 × 106 spores/ml) onto unwounded leaves. Three plants treated with sterile distilled water served as the control. All plants were placed in a humidity chamber (>95% relative humidity, 26°C) for 48 h after inoculation and then transferred into a greenhouse at 22/28°C. All inoculated leaves showed symptoms similar to those observed in the nursery 10 days after inoculation, whereas no symptoms were observed on the control leaves. The fungus was reisolated and confirmed to be A. alternata. A. alternata has previously been reported on Salvia spp. in Italy (Garibaldi et al. 2019) and Argentina (Kameniecki et al. 2013). To our knowledge, this is the first report of A. alternata on S. farinacea in China. Occurrence of the new disease caused by A. alternata should prompt full consideration for the use of proper disease management to protect S. farinacea.The author(s) declare no conflict of interest.

Occurrence of Leaf Spot Disease Caused by Alternaria crassa (Sacc.) Rands on Jimson Weed and Potential Additional Host Plants in Algeria.

A leaf spot pathogen Alternaria sp. was recovered from jimson weed, tomato, parsley, and coriander collected during surveys of blight diseases on Solanaceae and Apiaceae in Algeria. This species produced large conidial body generating long apical beaks that tapered gradually from a wide base to a narrow tip and short conidiophores originating directly from the agar surface. This species exhibited morphological traits similar to that reported for Alternaria crassa. The identification of seven strains from different hosts was confirmed by sequence analyses at the glyceraldehyde-3-phosphate dehydrogenase, RNA polymerase second largest subunit, and translation elongation factor 1-alpha loci. Further the pathogen was evaluated on jimson weed, coriander, parsley, and tomato plants, and this fungus was able to cause necrotic lesions on all inoculated plants. A. crassa is reported for the first time as a new species of the Algerian mycoflora and as a new potential pathogen for cultivated hosts.

Molecular characterization of lternaria solani isolates on tomato plant Lycopersicum esculentum Mill

Early blight disease causes severe damage to the foliar part of solanaceous crops including tomato. Fifteen isolates (12 from tomato, 2 from potato, 1 from pepper) were collected from different sources in Tripoli. Field and laboratory studies were conducted to determine cultural behaviour on PDA medium, morphological, pathogenic and molecular variation between isolates tested. Colonies of isolates revealed variation in their cultural behaviour on PDA medium ranging from cottony to appressed growth, with colour ranging between light to dark olivaceous. The pigments released by the isolates changed the medium colour to grey or brown. Morphological studies of the fungal isolates exhibited short conidiophores bearing a single or chains of paired conidia. This study revealed a significant variation in conidial size for the isolates tested ranging from 23.45 to 46.90 x 7.70 to 14.00 µm. Pathogenicity testes on fruits, plants, and detached leaves of tomato indicated a high significant variation between isolates tested ranging from highly to moderate or weak pathogenic. Genetic diversity of A. solani isolates using RAPD-PCR with oligonuclotide primers revealed significant differences in the appearance of polymorphic and monomorphic banding patterns. Three primers (OPA-07, OPA-09, OPJ-09) out of ten were able to determine the genetic fingerprints of tested isolates. Cluster analysis of RAPD-PCR products showed that primer OPA-07 was able to classify the isolates into five groups: group A (TF4,TF7, TL1, TL3), group B (TF1,TF3, TF8, PEF), group C (TF5, TF6, TF9, POL1, POL2), whereas the remaining two isolates TL2 and TF2 were unique in their patterns and were designated as group U1 and U2 respectively. Primer OPA-09 revealed four distinct genetic groups designated as: group A (TF4, TF6, TF7, TF8, TL2), group B (POL1, TL3, TF3), group C (TF5, POL2) and group D (TL1, TF1, TF2, TF9, PEF). However primer OPJ-09 was able to split the isolates tested into four distinct clusters: group A (TF1, TF7, TL3, PEF), group B (TF3, TF8, POL2), group C (TF2, TF6, TF9, TL2) and group D (TF4, TF5). The results of RAPD-PCR demonstrate existence of considerable variation in molecular characteristics of A. solan iisolates. Accordingly these isolates were classified into different groups and unique patterns with no obvious association between the pattern of clustering of the isolates and their host of origin, morphological characteristics and pathogenicity.

First Report of Brown Rot Caused by Monilia mumecola on Chaenomeles lagenaria in China

Chaenomeles lagenaria (Loisel) koidz (Rosaceae) is a traditional medicinal plant widespread in China known for its antitumor, heart-strengthening, and antiphlogistic properties (Zhang et al. 2014). Recently, symptoms of brown rot on C. lagenaria have been observed causing 60% yield losses in Changyang county, Hubei province, China. The pathogen mainly infected flowers and fruits. Infected flowers exhibited symptoms of small auburn spots on the tip of bracts and sepals at the beginning, developing along the main vein toward the base of the flowers, resulting in the decay of pedicel. Infected fruits developed round, dark-brown spots with tawny liquid on the surface and progressively rotted and withered. As the disease progressed, a white mycelium occurred on infected tissue in the presence of increased humidity. Symptomatic fruits and flowers were cut into small pieces and disinfected with 1% NaOCl solution for 1 min, rinsed in sterile water, air dried, and placed on potato dextrose agar (PDA). Pure cultures were obtained by using the single-spore isolation method and incubating at 25°C in light. The radial mycelial growth was 7.5 mm/day; compact colony with wavy edges was formed on PDA after 12 days of growth on a 9-cm Petri dish. The mycelium was colorless at first and turned incanus with time. Hyphae were septate and branched. Strings of spherical, colorless conidia with a size of 4 to 22 × 6 to 10 μm developed on short conidiophores. Based on morphological characteristics of mycelia and conidia, isolates were identified as Monilia mumecola (Wei 1979). The internal transcribed spacer (ITS) region of rDNA was amplified using ITS1 and ITS4 primers and sequenced. BLAST analysis of the PCR product showed 99% identity to M. mumecola (AB125620, AB125613). The sequence of isolate was shown in the supplementary file. To verify the pathogenicity, fresh disinfected fruits of C. lagenaria were used for the inoculation test. A group of 10 healthy fruits were inoculated with mycelium plugs; meanwhile, another group of 10 fruits were inoculated with conidial suspension at a concentration of 1 × 10⁶ per milliliter. Ten more noninoculated fruits served as controls. All inoculated and noninoculated fruits were placed in a light cultivation room at 25°C with saturated humidity. Five days later, inoculated fruits in both groups began to brown. By 10 days after inoculation, 100% of the inoculated fruits showed symptoms identical to those observed in the orchard. Control fruits remained symptomless. M. mumecola was reisolated from the inoculated fruits. The experiment was repeated twice. M. mumecola has only been reported to cause brown rot on Prunus mume in Japan (Harada et al. 2004) and peach in China (Hu et al. 2011). To our knowledge, this is the first report of brown rot caused by M. mumecola on C. lagenaria in China.

First Report of Leaf Spot Caused by Alternaria tenuissima on Coreopsis lanceolata in Anqing, China

Coreopsis lanceolata L. (Compositae) is native to North America and was introduced to Jiangxi Province of China as a landscape plant in the 1930s (Wan et al. 2008). This plant is distributed in gardens and green space of Anqing, such as Lotus Lake Park and Ling Lake Park. In May 2015, necrotic leaf lesions were observed on C. lanceolata growing in several land areas in Anqing, located in eastern China (30°50′ to 30°92′N; 117°03′ to 117°40′E). In 1.02 ha, disease incidence was 36%. Symptoms appeared on leaves as small, brown spots. Leaf spots enlarged progressively and developed into a gray-white lesions, surrounded by brown margins, and sometimes had a yellow halo. The size of leaf spot lesions ranged from 1 to 10 mm. Small fragments of tissue from infected leaves were surface disinfested with 70% ethyl alcohol, rinsed with distilled water, and then plated on potato dextrose agar in Petri plates in three repetitions. The plates were incubated at 25°C in darkness for 7 days, and strains were obtained by single-spore isolation. The colony of the fungus was olive-green with 1- to 2-mm white margin and abundant aerial hyphae. Numerous conidia that were melanized and obclavate to obpyriform in long sparsely branched chains on simple short conidiophores. Conidia ranged from 11.3 to 42.7 × 8.2 to 16.7 μm in size, showing one to six transverse septa and zero to two longitudinal septa. The isolates were identified as Alternaria tenuissima based on morphological characteristics as described by Simmons (2007). To confirm the fungus species, molecular identification was carried out by polymerase chain reaction using the internal transcribed spacer (ITS) region primers ITS1/ITS4 (White et al. 1990) and the partial coding sequence (cds) histone gene primers H3-1a/H3-1b (Luan et al. 2007), respectively, and sequenced. ITS sequences (accession nos. MK560081, MK575831, MK575832, MK575833, MK575834, MK575835, MK575836, and MK575837) and histone sequences (accession nos. MK598608, MK598609, MK598610, MK598611, MK598612, MK598613, MK598614, and MK598615) were deposited in GenBank. BLAST analysis of the resulting sequences from eight isolates all showed 100% identity with A. tenuissima strains (MG012286.1 for ITS region and MG012319.1 for partial cds histone gene region). To confirm pathogenicity, a conidial suspension (5 × 10⁵ conidia/ml) and sterile distilled water that served as a control were sprayed on healthy and detached leaves of C. lanceolata, separately. The inoculated leaves were maintained at 25°C with 90% relative humidity under a 12-h light photoperiod. After inoculating for 5 days, the symptoms were similar to those previously observed, and A. tenuissima was consistently reisolated from the artificially infected leaves by both morphology and molecular characterization. Control leaves remained healthy. To the best of our knowledge, this is the first report of A. tenuissima causing leaf spot on C. lanceolata in Anqing, China. Correct identification of this disease is of great importance to develop corresponding management strategies for preventing further spread of the pathogen to other areas.

First Report of Angelica keiskei Leaf Spots Caused by Alternaria alternata in China

Ashitaba (Angelica keiskei) is a flowering plant native to Japan and planted in many Asian countries (Park 2013). It was introduced into China in the late 1990s, where its functional components, including chalcone, coumarin, and flavonoids, are found to promote human health. Consequently, ashitaba has been used in various herbal products, wine, tea, and other supplements (Wu et al. 2016). The current cultivated area is 150 to 200 ha in China. From May to August 2017, a severe disease was discovered in Wuhan, Hubei province, China. Symptoms appeared as dark brown, oval to irregular necrotic spots surrounded by a yellowish border on approximately 30 to 40% of plants. The disease is a potential risk for the development of the ashitaba industry. To identify the pathogen, 10 symptomatic leaves were collected from 10 individual ashitaba plants. Small pieces of tissue (5 × 5 mm) were cut from the lesion margin, surface disinfested in 75% ethanol for 30 s and 0.1% HgCl₂ for 30 s, rinsed twice in sterilized distilled water, plated on potato dextrose agar amended with streptomycin sulfate, and then incubated at 25°C in the dark. Ten fungal colonies (K1 to K10) displaying gray-brown and gray-white aerial mycelia were consistently isolated from leaf lesions. Single-spore cultures were obtained on potato carrot agar in the dark at 25°C for 7 days. Conidia (n = 100) were observed and ranged from 10.0 to 31.0 × 7.0 to 11.0 μm and had three to six transverse and zero to three longitudinal septa. Short conidiophores arose singly and were approximately 15 to 76 μm long by 3 to 6 μm wide. Morphological characteristics were similar to those described for Alternaria alternata (Fr.) Keissl (Simmons 2007). To confirm this identification, genomic DNA was extracted from single conidial cultures of a representative isolate K3, and internal transcribed spacer regions (ITS), translation elongation factor 1-alpha gene (TEF-1a), glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH), endopolygalacturonase gene (endoPGs), and histone gene (H3 genes) were amplified using primers ITS1 and ITS4, TEF-1a, GAPDH, endoPGs, and H3 genes (Woudenberg et al. 2015). The sequences (MG661807, MK210168, MK210169, MK210170, and MK210171) were compared on NCBI GenBank and showed 100% identity with A. alternata isolate CBS 916.96. The fungal specimens were kept in the Vegetable Disease Research Laboratory of the Institute of Economic Crops, Hubei Academy of Agricultural Sciences. Pathogenicity tests were performed by spraying apparently healthy leaves of 5-month-old A. keiskei plants with a spore suspension of 10⁶ conidia/ml. Plants sprayed only with water served as a control (Mehmood et al. 2018). Three pots (three plants per pot) were used for each treatment. Plants were covered with plastic bags for 4 days after inoculation and maintained in the same greenhouse at an average temperature of 28°C. Experiments were carried out twice. Lesions developed on leaves 7 to 10 days after the artificial inoculation, whereas control plants remained healthy. To fulfill Koch’s postulates, the fungus was reisolated from the diseased leaves and confirmed to be A. alternata based on morphological characteristics and sequence analysis. To our knowledge, this is the first report of A. alternata causing leaf spots on A. keiskei in China. According to the USDA-ARS Fungal Database, it might be also the first report on this host worldwide.

Kevinhydea brevistipitata gen. et sp. nov. and Helicoma hydei sp. nov., (Tubeufiaceae) from decaying wood habitats

Kevinhydea brevistipitata gen. et sp. nov., and Helicoma hydei sp. nov., collected on decaying wood in terrestrial and freshwater habitats, respectively, are described and illustrated. Kevinhydea brevistipitata, the type species for a novel monotypic genus (Kevinhydea), is characterized by its macronematous, short conidiophores, and dictyosporous conidia. Helicoma hydei morphologically resembles H. guttulatum, but they are phylogenetically distinct species. Phylogenetic analyses of combined LSU, ITS, and TEF1α sequence data of 63 taxa were carried out to infer the phylogenetic affinity of new taxa within the family Tubeufiaceae. Additionally, phylogenetic analyses for the genus Helicoma, comprising 33 taxa, were performed separately to justify the new species H. hydei. Kevinhydea brevistipitata and Helicoma hydei are phylogenetically distinct from other species in Tubeufiaceae. A morphological comparison of dictyosporous hyphomycete genera in Tubeufiaceae is provided.

Bipolaris omanensis, a novel saprobic species of Bipolaris from Oman based on morphology and sequence data

Bipolaris species are responsible for important cereal diseases, worldwide and are often isolated as endophytes as well as saprobes. We are investigating the fungi in Oman. In this paper, we report a novel taxon of Bipolaris, collected from the leaves of Hibiscus rosa-sinensis, during the survey. The taxon is shown to be novel based on morphological and sequence data and introduced here as Bipolaris omanensis sp. nov. Bipolaris omanensis forms a sister clade to B. cookei based on the combined sequence analysis of internal transcribed spacers (ITS) and partial glyceraldehyde-3-phosphate dehydrogenase (GAPD) region, being distinct from the latter species in having shorter conidiophores, narrower conidia and having a higher number of septa.

A new species of Helicoön from Taiwan

Helicoön subglobosum sp. nov. from a decaying wood submerged in a freshwater stream at Juchi Town of Alishan area, Chiayi County, Taiwan, is described and illustrated with light and scanning electron micrographs. It differs from previously described species of Helicoön in having large subglobose conidia which are borne singly on very short conidiophores. The phylogenetic relationship of H. subglobosum and related taxa were sought by comparing the sequences of the ITS barcode and partial large subunit regions of the nuc rDNA. A synopsis of the 18 accepted species and a dichotomous key to the genus are given.

Two novel species of Paradictyoarthrinium from decaying wood

Two new hyphomycetes, Paradictyoarthrinium aquatica and P. hydei were collected and isolated from submerged wood and decaying wood in China and Thailand respectively. Morphologically, they line well with Paradictyoarthrinium in having superficial, gregarious, black, powdery fruiting bodies, macronematous conidiophores with unevenly dictyoseptate, muriform, subglobose to ellipsoidal dark brown conidia, but they differ from the other species in having short conidiophores. Phylogenetic analysis of combined LSU, ITS and RPB2 sequence data showed that six taxa of Paradictyoarthriniaceae, including the two new species, form a monotypic clade among the phylogenetically close families in Pleosporales with good support. Six isolates of Paradictyoarthrinium formed four distinct clades and represent four different species. Detailed descriptions and illustrations of the new species are provided, as well as the comparisons with related taxa.

First Report of Cadophora luteo-olivacea Causing Side Rot on Kiwifruit in Chile

HomePlant DiseaseVol. 102, No. 3First Report of Cadophora luteo-olivacea Causing Side Rot on Kiwifruit in Chile PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Cadophora luteo-olivacea Causing Side Rot on Kiwifruit in ChileJ. Auger, I. Pérez, C. Osorio-Navarro, and M. EsterioJ. Auger†Corresponding author: J. Auger; E-mail: E-mail Address: jauger@uchile.clSearch for more papers by this author, I. PérezSearch for more papers by this author, C. Osorio-NavarroSearch for more papers by this author, and M. EsterioSearch for more papers by this authorAffiliationsAuthors and Affiliations J. Auger † I. Pérez C. Osorio-Navarro M. Esterio , Laboratorio de Fitopatología Frutal y Molecular, Facultad de Ciencias Agronómicas, Universidad de Chile, C.P. 8820808, La Pintana, Santiago, Chile. Published Online:9 Jan 2018https://doi.org/10.1094/PDIS-09-17-1349-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Kiwifruit (Actinidia deliciosa [Chev] Ling et Ferguson cv. ‘Hayward’) can be stored for over 6 months at 0 ± 1°C. However, in recent years a postharvest disease of kiwifruit, characterized by a side rot appearing during harvest or after 3 to 6 months postharvest cold storage period, has been observed in several packinghouses in central Chile. Symptoms on kiwifruit were depressed and elliptical areas, associated with brown-violet skin and brown pulp. Symptomatic kiwifruit samples from different packinghouses were sterilized with 75% (v/v) ethanol, and infected tissue was placed onto potato dextrose agar (PDA) at 24°C in the dark for a 7-day period. Single spore colonies were flat, felty, and cottony in the middle, with smooth margins, with an even edge and varying in color from white turning to gray/black-olivaceous. Microscopically, straight, septate, short conidiophores had mostly cylindrical monophialides with hyaline collarettes. Conidia (n = 50) from four representative isolates recovered from naturally infected kiwifruit (2VCBC, 2VCBD, 2VCBF, and 2VCCD) were hyaline, unicellular, oblong elliptical or ovoid, and mostly biguttulated, measured 3.8 to 5.8 × 2.2 to 3.5 µm (mean, 2.9 × 4.8 µm). Cultural and morphological pathogen characteristics were similar to those described for Cadophora sp. (Gramaje et al. 2011). Three loci (ITS, β-tubulin, and EF1-α) of the four representative isolates were sequenced using the primers ITS1/ITS4, Bt2a/Bt2b, and EF1-728F/EF1-986R (Travadon et al. 2015). BLAST analysis revealed ITS, β-tubulin, and EF1-α sequences (accessions nos. MF464553, MF464555, MF464558, and MF464562) to share 99 to 100% identity with Cadophora luteo-olivacea isolates in GenBank (accession nos. KT350592, KT350591, and KU720079); the sequences (accession nos. MF464554, MF464556, MF464559, and MF464563) were compared with those of C. luteo-olivacea in the NCBI GenBank database and had 99% nucleotide sequence identity (accession nos. KF764682, KF764648, and KF764647), and the sequences (accession nos. MF772484, MF772481, MF772482, and MF772480) were 100% identical to C. luteo-olivacea sequences in GenBank (accession nos. KT350599, KT350598, and KT350597), respectively. Twenty ‘Hayward’ kiwifruits (per representative isolates) were wounded-inoculated in the fruit equatorial region with 20 μl of a spore suspension (106 conidia/ml) prepared from a 15-day-old PDA culture and incubated at 24°C in darkness. Typical symptoms appeared between 8 and 12 days. Kiwifruits inoculated with sterile distilled water remained symptomless. Fungi isolated from the lesions had morphological characteristics that resembled the original isolates from infected fruits. The identity of the reisolations was confirmed as C. luteo-olivacea by sequencing, thus completing Koch’s postulates. C. luteo-olivacea has been identified associated with a similar symptom (skin pitting) on kiwifruit stored long-term in Italy (Piano at al. 2001; Spadaro et al. 2010). In kiwifruit orchards, C. luteo-olivacea is normally a soil-borne microorganism and may be transported into packing houses on fruit skins or in harvest bins (Gilardi et al. 2007). Side rot caused by C. luteo-olivacea represents an economically significant problem for the kiwifruit packinghouses in Chile, owing to the lack of effective postharvest fungicides and the limited knowledge of the pathogen and disease epidemiology. To our knowledge, this is the first report of side rot of kiwifruit caused by C. luteo-olivacea in Chile.

Two new Leptographium spp. reveal an emerging complex of hardwood-infecting species in the Ophiostomatales.

Species of Leptographium are generally characterized by mononematous conidiophores and are commonly associated with bark beetles and weevils. These species are responsible for sapstain and in some cases serious diseases on a range of primarily coniferous trees. In comparison with coniferous trees, the occurrence of Leptographium species on hardwood trees has been poorly studied in Europe. During a survey of ophiostomatoid fungi on various tree species in Norway and Poland, three unusual species, which fit the broader morphological description of Leptographium spp., were found in association with Scolytus ratzeburgi, Dryocoetes alni and Trypodendron domesticum on a variety of hardwoods, and from wounds on Tilia cordata. Phylogenetic analyses of sequence data for three gene regions (ITS2-LSU, β-tubulin, and TEF1-α) showed that these Leptographium species are phylogenetically closely related to each other and form a well-supported lineage that included Grosmannia grandifoliae and Leptographium pruni. The first species could be distinguished from the other Leptographium species based on conidiophores arising from spiral hyphae, chlamydospore-like structures and a hyalorhinocladiella-like synanamorph in culture. The second species differs from the previous one by having distinctly shorter conidiophores and smaller conidia. This species also produces a well-developed sporothrix-like synanamorph with denticulate conidiogenous cells. Based on these unusual morphological characteristics and distinct DNA sequences, these fungi were recognised as new taxa for which the names Leptographium trypodendri sp. nov. and L. betulae sp. nov. are provided. The third group of isolates belonged to Grosmannia grandifoliae, representing the first report of this species outside of the USA. The newly defined G. grandifoliae complex is the first species complex in Leptographium s.l. consisting of only hardwood-infecting species.

Calcarisporium xylariicola sp. nov. and introduction of Calcarisporiaceae fam. nov. in Hypocreales

During a survey of fungicolous fungi, a novel taxon from the surface of stroma of an unidentified Xylaria species was collected. Phylogenetic analyses showed that this taxon clustered with Calcarisporium sp. and C. arbuscula isolates, but was resolved as a distinct species. A detailed morphological examination coupled with phylogenetic analysis indicated that the taxon represented a new species. Calcarisporium xylariicola sp. nov. is thus introduced. The new taxon is characterized by short conidiophores with swollen bases and less length/width ratio of conidia that distinguish it from other Calcarisporium species. Calcarisporium is presently placed in Hypocreales genera, incertae sedis genus. Species in the genus are largely fungicolous, or occasionally caulicolous or foliicolous, and have hyaline, erect, verticillate conidiophores and sympodial, polyblastic conidiation. A phylogenetic analysis of combined SSU, ITS, LSU, TEF and RPB2 sequence data from Calcarisporium species and other taxa in Hypocreales indicate that Calcarisporium is a distinct lineage from other families. Therefore, a new family, Calcarisporiaceae, in Hypocreales is introduced.