Short Conidiophores Research Articles

FIRST REPORT OF FUSARIUM ROT CAUSED BY FUSARIUM OXYSPORUM ON GRAPEFRUIT IN PAKISTAN

During year 2014-2015, severe infection was observed on grapefruit plants in Rawalpindi and Islamabad Capital Territory (ICT), Pakistan. Symptoms appeared as brown, oval or round spots, with varying sizes ranging from small spot (5 mm) to decay of the entire fruit. Twenty-five infected fruits were collected, surface-sterilized and 3-mm-diameter sections were placed on potato dextrose agar (PDA) medium at 26°C. After 4 days, the mycelia of the isolates were delicate, creamy white and pink or purple tinge, and their margins slightly lobed or smooth. Microconidia were single, oval to reniform and monophialides type. Moon crest shape macroconidia were produced in sporodochium with multiseptum. Short aerial conidiophores were unbranched, producing one-cell conidia in false head (Hussain et al., 2012). The microscopic structure was similar to that of Fusarium oxysporum. Molecular identification of pathogen was achieved by its rDNA sequence analysis. Genomic DNA was extracted from a single pure colony of fungus and its 18S rDNA region was amplified (White et al., 1990). Sequence analysis showed 99% similarity with Fusarium oxysporum strain NSF2 18S ribosomal RNA gene, partial sequence (KR611565.1). This sequence was deposited in NCBI database (KX384665). To prove Koch’s postulates, ten fruit were spray inoculated with isolated fungal conidial suspension (1 × 105 spores/ml of water). All inoculated fruit showed similar symptoms. No spots or lesions were observed on controlled fruits. F. oxysporum was re-isolated from the diseased fruits. To our knowledge this is the first report of F. oxysporum causing fruit rot on grapefruit.

Biodiversity, Distribution and Taxonomy of Conidial Fungus Corynespora (Corynesporascaceae) Associated With Malvaceae

This paper deals the biodiversity, distribution and taxonomy of conidial fungus Corynespora associated with family Malvaceae, including a new species belonging to the genus Corynespora, viz. C. sidae sp. nov., was discovered on living leaves of Sida acuta Burm.f. (Malvaceae) from University Campus of Deen Dayal Upadhyay Gorakhpur University, Gorakhpur, Uttar Pradesh (UP), India. This species is described, illustrated and compared with similar taxa reported on Malvaceae based on morphological characters. The novel species is characterized by shorter conidiophores and longer and smooth conidia. The nomenclatural novelties were submitted in Mycobank.

First Report of Alternaria alternata Causing Leaf Spot on Bruguiera gymnorrhiza in China.

Bruguiera gymnorrhiza (L.) Savigny is an important mangrove tree species that grows in the intertidal regions of the tropical and subtropical coastlines. In a survey conducted in March 2014, a leaf spot disease on this plant was observed in Sea View Promenade in Zhanjiang, Guangdong Province, China. Symptoms on leaves initially appeared as small circular to irregular, dark brown, necrotic, sunken spots with an average diameter of 4 to 7 mm. The spots gradually enlarged in size, becoming irregular, or remained circular with concentric rings or zones. In the latter, the spots coalesced, and the leaves withered, dried, and fell from the plants. Leaf tissues (3 × 5 mm), cut from the margins of lesions, were surface-disinfected, placed on potato dextrose agar (PDA), and incubated at 28°C with a 12-h photoperiod. Five fungi (MLL1 to MLL5) with different morphological characteristics were obtained. To fulfill Koch's postulates, wounded and nonwounded leaves were inoculated. Fresh wounds were made with a sterile needle on 10 detached leaves and 10 leaves on five living plants for fungi MLL1 to MLL5 independently. Mycelial plugs of each fungus were applied to wounded and nonwounded leaves. For the control, 10 leaves on five living plants were inoculated with agar plugs in a similar manner, to both wounded and nonwounded leaves. All treatments were incubated in a humid chamber in the dark at 28°C. Leaf spots identical to those observed in the field were observed on the wounded leaves inoculated with fungus MLL3 after 3 to 4 days, while the other four fungi and the control remained symptomless. The 10 nonwounded leaves inoculated with fungus MLL3 were also infected after 5 days. The fungus, with the same colony and conidial morphology as MLL3, was re-isolated from the affected leaves. The pathogenic test was repeated three times under the same conditions. Hyphal tips of MLL3 were transferred to PDA for morphological observation. Colonies of white-to-dark-gray mycelia, black on the underside, formed on PDA. The colonies were further identified as Alternaria sp., based on the dark brown, obclavate to obpyriform catenulate conidia with longitudinal and transverse septa tapering to a prominent beak attached in chains on a simple and short conidiophore (3). Conidia varied from 22.5 × 40.26 to 3.95 × 5.79 μm and had three to eight transverse and zero to four longitudinal septa, with a beak length of 0 to 7.25 μm. For molecular identification, PCR was carried out using internal transcribed spacer (ITS) region primers ITS1/ITS4, partial sequences of the beta tubulin gene primers Bt1a-Bt1b (1), and A. alternata species-specific primers AAF2/AAR3 (2). The PCR products were subjected to direct sequencing. The resulting sequences were compared against the GenBank nucleotide database by using a BLAST alignment, which revealed that MLL3 had 99 to 100% identity with A. alternata for the ITS, Bt1a-Bt1b, and AAF2/AAR3 regions (GenBank Accession Nos. KF669893, GQ240308, and KJ716876, respectively). Sequences for MLL3 were deposited in GenBank under accession numbers KJ767515, KJ921779, and KJ921778. According to both morphological and sequence analyses, the pathogen of the leaf spot of B. gymnorrhiza was identified as A. alternata. To our knowledge, this is the first report of A. alternata on leaves of B. gymnorrhiza in China. This pathogen could cause serious foliar damage and threaten the survival, growth, and fitness of the local B. gymnorrhiza community.

Phylogenetic placement of a new species of Corynesporopsis from dead acacia wood indicates occurrence of tretic conidiogenesis within Xylariales

A new species of Corynesporopsis from rotting wood of Acacia confusa differs from similar species with one-septate conidia by comparatively short conidiophores and conidia and deeper brown pigmentation of conidiogenous cells than of more proximal cells of the conidiophore. Morphology in culture differs from that in situ mainly by hyaline vegetative hyphae and branched conidiophores. A phylogenetic analysis including a species of Corynesporopsis indicates a close relationship to Xylariales and the occurrence of tretic conidiogenesis in this order. Corynesporopsis quercicola is a new record for Taiwan.

Occurrence of a Fruit Spot Disease of Pear Caused by Septoria pyricola in Tyrnavos Larissa, Northern Greece

Pear tree (Pyrus communis) is an important crop in Greece. In 2012, fruits of the pear cv. Kontoula were observed in commercial fields located in Tirnavos, Prefecture of Larrisa, Greece, with symptoms of well-defined brown angular margins and their grayish white centers in which a few pycnidia (about 180 × 150 μm) were produced within the spots. Pycnidia were dark, separate, and globe-shaped with an ostiole (opening at the apex) from which conidia (about 40 to 60 × 3 μm) were extruded, and erupted through the surface of the infected tissue. Conidia were produced on short conidiophores. They were clear, narrowly elongated to filiform, and several-celled. The pathogen was isolated on acidified-PDA (2.5 ml 85% lactic acid per liter of nutrient medium) and incubated at 23°C for 7 days. The pathogen was identified as Septoria pyricola Desm. based on morphological characteristics. Koch's postulates were completed in the laboratory by placing a 40-μl drop of suspension (4 × 105 conidia ml-1 of water) on a wounded area of healthy fruits of cv. Kontoula. Fruits were surface sterilized with dipping in 0.1% chlorine solution, allowed to dry in a laminar flow hood. There were 15 inoculated and 15 control fruits (similarly inoculated with sterile distilled water) in a randomized design. Fruits were covered with perforated polythene bags to maintain a high humidity necessary for infection and these bags were removed 48 h after inoculation and maintained at room temperature (23 ± 2°C). Lesion development was recorded daily for each fruit. Koch's postulates were satisfied after re-isolating the fungus from inoculated fruit that developed symptoms similar to those observed on fruits collected from fields. Symptoms of this disease were found in all pear orchards cultivating the cv. Kontoula located in Tyrnavos (a municipality in the Prefecture of Larissa). Symptoms of septoria leaf spot were also observed in the above pear orchards. In contrast, no symptom of septoria fruit spot and septoria leaf spot was observed in apple orchards of the above regions. To our knowledge, this is the first report of the occurrence of S. pyricola as causal agent of fruit spot of pears in Greece. Fruit spotting is relatively uncommon; nevertheless, Sivanesan (3) gives two reports of conidia infecting pear fruits from Italy and South Africa (1,2).

First Report of Alternaria Black Spot of Pomegranate Caused by Alternaria alternata in Spain.

Since 2010, a new foliar and fruit disease was observed in pomegranate (Punica granatum L.) orchards in Alicante Province (eastern Spain). Symptoms included black spots on leaves and fruits, as well as chlorosis and premature abscission of leaves. Fungal isolates were obtained by surface-disinfecting small fragments of symptomatic leaf and fruit tissues in 0.5% NaOCl, double-rinsing in sterile water, and plating them onto potato dextrose agar (PDA) amended with 0.5 g/liter of streptomycin sulfate. Gray-to-black colonies were obtained, which were identified as Alternaria sp. based on the dark, brown, obclavate to obpyriform catenulate conidia with longitudinal and transverse septa tapering to a prominent beak attached in chains on a simple and short conidiophore (4). Conidia (n = 100) measured (12.2-) 20.2 (-27.6) × (5.7-) 9.2 (-12.0) μm, and had 3 to 6 transverse and 0 to 5 longitudinal septa. Single spore cultures were obtained and their genomic DNA was extracted. The internal transcribed spacer (ITS) region of rDNA and partial sequences of the beta tubulin gene were amplified and sequenced with primers ITS1-ITS4 and Bt1a-Bt1b, respectively (3). BLAST analysis of the sequences showed that they were 100% identical to a pathogenic A. alternata (Fr.) Keissl. isolate obtained from black spot disease of pomegranate in Israel (Accession No. JN247826.1, ITS and Accession No. JN247836.1, beta tubulin) (2). As all the sequences obtained showed 100% homology, ITS and beta tubulin sequences of a representative isolate (1516B) were submitted to GenBank (KF199871 and KF199872, respectively). In addition, a PCR reaction with specific primers (C_for/C_rev) designed to recognize highly virulent isolates of A. alternata causing black spot of pomegranate was used with all isolates (2). A characteristic fragment of ~950 bp was amplified in two isolates: 1552B and 1707B. Pathogenicity was assessed on plants and detached fruit of pomegranate cv. Mollar (1). Two-year-old pomegranate trees were inoculated with isolates 1552B and 1707B by spraying a conidial suspension (106 conidia/ml) onto the upper and lower leaf surfaces. Five plants per fungal isolate were used and five control plants were sprayed with sterile water. Plants were covered with transparent plastic bags and incubated in a growth chamber for 1 month at 25°C, with a 12-h photoperiod. One-month-old fruits were surface sterilized in 1.5% sodium hypochlorite solution for 1 min and rinsed twice in water. Two filter paper squares (5 × 5 mm) were dipped in the conidial suspensions and placed on the fruit surface. Inoculated fruit were incubated in a humid chamber in the dark at 25°C. Ten fruit per fungal isolate were used and 10 control fruit were inoculated with sterile water. Black spots were visible on inoculated leaves and fruit, 10 and 3 days after inoculation, respectively. Symptoms were not observed on controls. The fungus was re-isolated from leaf and fruit lesions, confirming Koch's postulates. Leaf black spot of pomegranate caused by A. alternata was first described in India in 1988, and later in Israel in 2010 affecting both fruit and leaves (1). To our knowledge, this is the first report of the disease in Spain, where it could represent a threat for pomegranate cultivation due to the increasing amount of area dedicated to this crop.

First Report of Leaf Spot Caused by Alternaria alternata on Chinese Dwarf Banana in China.

The Chinese dwarf banana (Ensete lasiocarpum) is one of the ornamental bananas that belongs to Musaceae family. The plant is native to the southwestern China, where it grows semi-wild in the mountains between 1,500 and 2,500 m above sea level. During July 2011, a leaf spot disease on this plant was observed in the campus and parks in Kunming, Yunnan Province. The incidence level was about 22%, mainly on the old leaves. The leaf symptoms were irregular spots with gray to off-white centers surrounded by dark brown margins, and usually also surrounded by chlorotic halos. Leaf tissues (3 × 5 mm), cut from the margins of lesions, were surface-disinfected (95% ethanol for 3 min, 0.1% HgCl2 for 2 min, rinsed three times with sterile water), plated on potato sucrose agar (PSA), and incubated at 26°C under natural lights. The same fungus was consistently isolated from the diseased leaves. Colonies of white-to-dark gray mycelia formed on PSA that were black on the underside. The colonies were further identified as Alternaria sp. based on the dark brown, obclavate to obpyriform catenulate conidia with longitudinal and transverse septa tapering to a prominent beak attached in chains on a simple and short conidiophore (2). Conidia were 5.26 to 30.26 μm long and 3.95 to 15.79 μm wide, averaging 10.21 (±3.17) × 20.02 (±5.75) μm (n = 50), with a beak length of 0 to 7.89 μm, and had 3 to 8 transverse and 0 to 3 longitudinal septa. PCR amplification was carried out by utilizing universal rDNA-ITS primer pair ITS4/ITS5 (1). The ITS region of isolate DY1 (GenBank Accession No. KF516556) was 572 bp in length. BLAST search revealed 99% identity with two Alternaria alternata isolates (JF440581.1 and GQ121322.2). Phylogenetic analysis (MEGA 5.1) using the neighbor-joining algorithm placed the isolate in a well-supported cluster with other A. alternata isolates. The pathogen was identified as A. alternate (Fr.:Fr.) Keissler based on the morphological characteristics and rDNA-ITS sequence analysis. To confirm pathogenicity, Koch's postulates were performed on detached leaves of E. lasiocarpum inoculated with mycelial plugs with ddH2O and agar plugs as a control. Leaf spots identical to those observed in the field developed in 9 days on the inoculated leaves but not on the control. The inoculation assay used three leaves, totaling 72 spots for control and 36 spots for inoculation. The experiments were repeated once. A. alternata was consistently re-isolated from the inoculated leaves. The symptom developed easier with wounds. To our knowledge, this is the first report of E. lasiocarpum leaf spot disease caused by A. alternata in China and the world.

First Report of Alternaria tenuissima Causing Postharvest Decay on Apple Fruit from Cold Storage in the United States.

Apples are grown and stored for 9 to 12 months under controlled atmosphere conditions in the United States. During storage, apples are susceptible to various fungal pathogens, including several Alternaria species (2). Alternaria tenuissima (Nees) Wiltshire causes dry core rot (DCR) on apples during storage and has recently occurred in South Africa (1). Losses range widely, but typically occur at 6 to 8% annually due to this disease (2). In February 2013, 'Nittany' apples with round, dark-colored, dry, spongy lesions were obtained from wooden bins in a commercial cold storage facility located in Pennsylvania. Symptomatic fruits were transported to the lab, rinsed with sterile water, and the lesions were sprayed with 70% ethanol until runoff and wiped dry. The skin was aseptically removed with a scalpel, and asymptomatic tissue was placed onto potato dextrose agar (PDA) and incubated at 25°C. Two single-spore isolates were propagated on PDA and permanent cultures were maintained as slants and stored at 4°C. The fungus produced a cottony white mycelium that turned olive-green to brown with abundant aerial hyphae and had a dark brown to black reverse on PDA. Isolates were identified as Alternaria based on conidial morphology as the spores were slightly melanized and obclavate to obpyriform catentulate with longitudinal and transverse septa attached in unbranched chains on simple short conidiophores. Conidia ranged from 10 to 70 μm long (mean 27.7 μm) and 5 to 15 μm wide (mean 5.25 μm) (n = 50) with 1 to 6 transverse and 0 to 2 longitudinal septa. Conidial beaks, when present, were short (5 μm or less) and tapered. Mycelial genomic DNA was extracted, and a portion of the histone gene (357 bp) was amplified via gene specific primers (Alt-His3-F/R) using conventional PCR (Jurick II, unpublished). The forward and reverse sequences were assembled into a consensus representing 2× coverage and MegaBLAST analysis showed that both isolates were 100% identical to Alternaria tenuissima isolates including CR27 (GenBank Accession No. AF404622.1) that caused DCR on apple fruit during storage in South Africa. Koch's postulates were conducted using 10 organic 'Gala' apple fruit that were surface sterilized with soap and water, sprayed with 70% ethanol, and wiped dry. The fruit were aseptically wounded with a nail to a 3 mm depth, inoculated with 50 μl of a conidial suspension (1 × 104 conidia/ml), and stored at 25°C in 80 count boxes on paper trays for 21 days. Mean lesion diameters on inoculated 'Gala' apple fruit were 19.1 mm (±7.4), water only controls (n = 10 fruit) were symptomless, and the experiment was repeated. Symptoms observed on artificially inoculated 'Gala' apple fruit were similar to the decay observed on 'Nittany' apples from cold storage. Based on our findings, it is possible that A. tenuissima can cause decay that originates from wounded tissue in addition to dry core rot, which has been reported (1). Since A. tenuissima produces potent mycotoxins, even low levels of the pathogen could pose a health problem for contaminated fruit destined for processing and may impact export to other countries. To the best of our knowledge, this is the first report of alternaria rot caused by A. tenuissima on apple fruit from cold storage in the United States.

A new species of Manoharachariella (hyphomycetes) from Central Anatolia, Turkey

Manoharachariella elsadii is described as a new species from Turkey. It differs from the two known species by possessing smaller conidia with fewer septa. In addition, it has shorter conidiophores than M. indica and longer conidiophores than M. lignicola.

First Report of Alternaria Blight of Potato Caused by Alternaria tenuissima in China.

Potato (Solanum tuberosum L.) is grown worldwide as a major food crop. Potato early blight is an important disease caused by Alternaria solani (4). In 2011, diseased potato leaves with blight symptoms were collected from 21 sites (incidence averaged 60% for about 2,000 ha of potato fields examined) in Gansu Province, northwest China. Small pieces of tissue taken from the margin between healthy and diseased tissues were surface-disinfected in 0.3% NaOCl for 2 min, rinsed with sterilized, distilled water, then placed on potato dextrose agar (PDA) at 25°C in the dark. Two of 24 Alternaria isolates from single-spore cultures were identified preliminarily as A. tenuissima, and the remaining isolates as A. solani or A. alternata, based on morphological traits. Colony appearance on potato carrot agar (PCA) was loosely cottony under a day/night cycle of 8 h fluorescent light/16 h dark at 22°C for 7 days (3). The isolates were characterized by formation of unbranched conidial chains up to 12 conidia in length, with one or two lateral branches forming occasionally. Conidia were typically ovoid to obclavate, and ranged from 20.4 to 42.4 × 7.7 to 13.2 μm. Transverse septa and longitudinal septa of conidia varied from 1 to 6 and 0 to 2, respectively. Short conidiophores arose singly and were 15.1 to 76.8 μm long by 2.4 to 6.2 μm wide. The internal transcribed spacer (ITS) region of rDNA and partial coding sequence of a histone gene were amplified from genomic DNA of the two A. tenuissima isolates using the ITS1/ITS4 and H3-1a/H3-1b primers (2), respectively. The ITS sequences of the two isolates (GenBank Accession Nos. JX495165 and JX495166) were 100% identical to those of A. tenuissima strains sdau 07-100 and BL08-3 (GQ871507 and AB470887), as well as to other Alternaria species, but the partial histone gene sequences (JX495167 and JX495168) were 99% identical to those of A. tenuissima isolates CR27, MA1, MA6, and CN-L-01 (AF404622, AF404633, AF404634, and EF371552, respectively) with less similarity to those of other Alternaria spp. Therefore, the isolates were identified as A. tenuissima based on morphological and molecular characteristics. Pathogenicity tests were conducted by inoculating detached leaves (30 per isolate) from 45-day-old plants of potato cv. Favorita with 20 μl drops (one drop per leaf) of a conidial suspension containing 106 conidia/ml in sterilized, distilled water. Thirty control leaves were inoculated similarly with sterilized, distilled water. Inoculated leaves were incubated in chambers at 25°C and 90% RH with a 12-h photoperiod/day. After 7 days, symptoms on the inoculated leaves were similar to those naturally occurring on the original plants, and the two cultures were reisolated consistently from those leaves, and the species identity was confirmed by morphological and molecular characteristics, fulfilling Koch's postulates. The control leaves remained asymptomatic and Alternaria was not isolated from those leaves. Alternaria blight of potato caused by A. tenuissima was previously detected in Iran (1). To our knowledge, this is the first report of A. tenuissima causing blight on potatoes in China.

First Report of Alternaria Leaf Spot of Banana Caused by Alternaria alternata in the United States.

Research efforts were initiated in 2003 to identify and introduce banana (Musa spp.) cultivars suitable for production in Georgia (1). Selected cultivars have been evaluated since 2009 in Tifton Banana Garden, Tifton, GA, comprising of cold hardy, short cycle, and ornamental types. In spring and summer of 2012, 7 out of 13 cultivars (African Red, Blue Torres Island, Cacambou, Chinese Cavendish, Novaria, Raja Puri, and Veinte Cohol) showed tiny, oval (0.5 to 1.0 mm long and 0.3 to 0.9 mm wide), light to dark brown spots on the adaxial surface of the leaves. Spots were more concentrated along the midrib than the rest of the leaf and occurred on all except the newly emerged leaves. Leaf spots did not expand much in size, but the numbers approximately doubled during the season. Disease incidences on the seven cultivars ranged from 10 to 63% (10% on Blue Torres Island and 63% on Novaria), with an average of 35% when a total of 52 plants were evaluated. Six cultivars including Belle, Ice Cream, Dwarf Namwah, Kandarian, Praying Hands, and Saba did not show any spots. Tissue from infected leaves of the seven cultivars were surface sterilized with 0.5% NaOCl, plated onto potato dextrose agar (PDA) media and incubated at 25°C in the dark for 5 days. The plates were then incubated at room temperature (23 ± 2°C) under a 12-hour photoperiod for 3 days. Grayish black colonies developed from all the samples, which were further identified as Alternaria spp. based on the dark, brown, obclavate to obpyriform catenulate conidia with longitudinal and transverse septa tapering to a prominent beak attached in chains on a simple and short conidiophore (2). Conidia were 23 to 73 μm long and 15 to 35 μm wide, with a beak length of 5 to 10 μm, and had 3 to 6 transverse and 0 to 5 longitudinal septa. Single spore cultures of four isolates from four different cultivars were obtained and genomic DNA was extracted and the internal transcribed spacer (ITS1-5.8S-ITS2) regions of rDNA (562 bp) were amplified and sequenced with primers ITS1 and ITS4. MegaBLAST analysis of the four sequences showed that they were 100% identical to two Alternaria alternata isolates (GQ916545 and GQ169766). ITS sequence of a representative isolate VCT1FT1 from cv. Veinte Cohol was submitted to GenBank (JX985742). Pathogenicity assay was conducted using 1-month-old banana plants (cv. Veinte Cohol) grown in pots under greenhouse conditions (25 to 27°C). Three plants were spray inoculated with the isolate VCT1FT1 (100 ml suspension per plant containing 105 spores per ml) and incubated under 100% humidity for 2 days and then kept in the greenhouse. Three plants sprayed with water were used as a control. Leaf spots identical to those observed in the field were developed in a week on the inoculated plants but not on the non-inoculated control. The fungus was reisolated from the inoculated plants and the identity was confirmed by morphological characteristics and ITS sequencing. To our knowledge, this is the first report of Alternaria leaf spot caused by A. alternata on banana in the United States. Occurrence of the disease on some banana cultivars in Georgia provides useful information to potential producers, and the cultivars that were observed to be resistant to the disease may be more suitable for production.

English

  Phyllactinia cassiae-fistulae and its Ovulariopsis anamorph, a causal agent of powdery mildew on Cassia fistula, have been found in Thailand for the first time. Phylogenetic analysis using the 28S ribosomal DNA sequences clearly demonstrated that P. cassiae-fistulae distinctly formed a unique clade at the basal part ofPhyllactinia with 100% bootstrap support. This phylogenetic analysis supports the unique morphology of P. cassiae-fistulae anamorph having cylindrical-ellipsoil conidia and short conidiophores similar to Oidium species.   Key words: Morphology, phylogeny, powdery mildew, Cassia fistula, Senna siamea.

First Report of Begonia Elatior Wilt Disease Caused by Fusarium foetens in France.

Fusarium foetens is a destructive vascular pathogen on Begonia, mainly on cultivars of Begonia elatior hybrids (Begonia × hiemalis), which has recently been identified in Europe and Northern America (1,3). This Fusarium species has been responsible for severe damage in the begonia flower industry (1) and is listed as an EPPO A2 quarantine pathogen since 2007. In May 2007, wilted potted plants of B. elatior showing chlorotic leaves and basal stem rot were observed in a nursery located in the west of France (La Flèche, Sarthe). Symptomatic foliar and basal stem pieces were plated on a Fusarium semi selective medium, dichloran chloramphenicol peptone agar (DCPA), and on malt agar medium supplemented with 100 ppm chloramphenicol. Homogeneous mycelium of a Fusarium species developed from both types of tissue and on both media, and was transferred to potato dextrose agar (PDA) and to spezieller nährstoffarmer agar (SNA) media for morphological examination. Microscope slides were then prepared by pressing gently a clear self-adhesive tape onto the surface covered by mycelium and sporodochia, which was further stained with lactic acid/methylene blue. Typical multiseptate (often three septa), hyaline, slightly curved Fusarium macroconidia 29.2 to 41.8 (32.5) × 3.6 to 4.5 (4.3) μm were collected in sporodochia. In the aerial mycelium, long and short conidiophores with mono- or polyphialidic cells bearing false heads of ellipsoidal microconidia were observed. In addition, a pungent distinctive odor was produced by the mycelium grown on PDA. These features were consistent with F. foetens (2). To support the diagnosis, total DNA was further extracted from the pure culture and a partial region of the translation elongation 1 (tef1) gene was amplified by PCR using EF1-EF2 primer pair (4). Nucleotide sequence was determined and deposited on GenBank (Accession No. JX298790). Analysis of the sequence by BLAST showed that it was 100% identical with all the available F. foetens sequences, which confirmed our morphological diagnosis. To our knowledge, this is the first official report of F. foetens in France. Since this first detection, F. foetens was again identified in 2010 in another nursery located in the Pays de la Loire on collapsed B. elatior. Approximately 15 to 20% of the Begonia plants showed typical Fusarium wilt symptoms and the infected lots were systematically destroyed. The origin of these infections could not be traced back since the mother plants tested negative. The disease is considered as eradicated in France but causes major economic losses to Begonia growers and marketers in regions where the disease is established (2).

Pseudoidium javanicum, a new species of powdery mildew on Acalypha spp. from Indonesia

Pseudoidium javanicum is proposed as a new species based on analyses of 28S, ITS and IGS rDNA sequences, and morphological data. This new species was found on Acalypha wilkesiana var. marginata, A. argentea, and A. cristata collected from Cibodas Botanical Garden, Bogor (West Java Province, Indonesia). Our analyses showed that all these specimens have identical rDNA sequences and similar morphological characteristics. They form a distinct clade separated from other species of Erysiphaceae. Pseudoidium javanicum differs from Erysiphe acalyphae by having shorter conidiophores and foot cells 1–3 times as long as the 0–2 following cells. The conidial size of Ps. javanicum is also smaller than that of E. jatrophae.

Clinical Spectrum of Exophiala Infections and a Novel Exophiala Species, Exophiala hongkongensis

We characterized 12 Exophiala strains isolated from patients over a 15-year period to the species level using phenotypic tests and internal transcribed spacer (ITS) and Rpb1 sequencing and described the clinical spectrum of the 12 patients. Eight patients had nail or skin infections, two had invasive infections, and two had colonization of the gastrointestinal tract. ITS and Rpb1 sequencing showed that 11 of the 12 strains were known Exophiala species (E. oligosperma [n = 3], E. jeanselmei [n = 2], E. lecanii-corni [n = 2], E. bergeri [n = 1], E. cancerae [n = 1], E. dermatitidis [n = 1], and E. xenobiotica [n = 1]), which included the first reported cases of onychomycosis caused by E. bergeri and E. oligosperma. The 12th strain (HKU32(T)), isolated from the nail clipping of the right big toe of a 68-year-old female patient with onychomycosis, possessed unique morphological characteristics distinct from other Exophiala species. It grew very slowly and had a velvety colony texture after 28 days, short conidiophores of the same olivaceous color as the supporting hyphae, numerous spores, and no chlamydospore-like cells. ITS, Rpb1, β-tubulin, and β-actin gene sequencing unambiguously showed that HKU32(T) was clustered with but formed branches distinct from other Exophiala species in phylogenetic trees. We propose the new species Exophiala hongkongensis to describe this novel fungus.

The anamorphic genus Monotosporella (Ascomycota) from Eocene amber and from modern Agathis resin

The anamorphic fungal genus Monotosporella (Ascomycota, Sordariomycetes) has been reco-vered from a piece of Early Eocene Indian amber, as well as from the surface of extant resin flows in New Caledonia. The fossil fungus was obtained from the Tarkeshwar Lignite Mine of Gujarat State, western India, and was part of the biota of an early tropical angiosperm rainforest. The amber inclusion represents the second fossil record of Sordariomycetes, as well as the first fossil of its particular order (either Savoryellales or Chaetosphaeriales). The fossil fungus is distinguished from extant representatives by possessing both short conidiophores and small two-septate pyriform conidia, and is described as Monotosporella doerfeltii sp. nov. Inside the amber, the anamorph is attached to its substrate, which is likely the degraded thallus of a cladoniform lichen. The extant New Caledonian species is assigned to Monotosporella setosa. It was found growing on semi-solidified resin flows of Agathis ovata (Araucariaceae), and is the first record of Monotosporella from modern resin substrates.

Powdery mildew on spinach (Spinacia oleracea L.)

Symptoms resembling powdery mildew appeared on spinach crops during April and May in 2007. Infected plants have suppressed growth, smaller and degenerated young leaves. The affected leaves become yellowish and wilt in a short time. High temperatures and draught conditions cause drying out of the affected plants. The symptoms are similar to physiological degeneration but are found on single plants or on small groups of plants. When plants are carefully examined, fine, exogenic mycelium is found on the leave blades. The mycelium can be clearly seen close to the main veins where it becomes denser and forms mycelium patches. On the leaf and flower stalks and plant stems the mycelium is white and fine at the beginning, and later becomes grayish. Under microscope analysis ectophytic mycelia of exogenic origin and short chains of spores are observed. On short conidiophores, chains with two types of conidia are formed: macro conidia that are one-celled, colorless, thin-walled, elliptical to cylindrical, sized 24.5-28.4 x 17.5 ?m; and micro conidia - ovoid to elliptical, sized 10.4-14.1 x 7.7 ?m. Teleomorphs are found in groups or as a single structure mainly close to the leaf veins. They are roundish and have appendages with uncinate-circinate to helicoids apex, sized - 87.5- 150 ?m. Cleistothecia have 4-5 to 8 asci (68.0 x 38.0 ?m), with 4 to 8 elliptical ascospores, sized 15.5-22.0 ? 11.0-17.5 ?m. The causal agent of powdery mildew on spinach found in Bulgaria has been identified as Uncinula spp. (Sawadaea spp.), Euoidium type anamorph, subspecies spinaciae.

Polyphasic analysis of intraspecific diversity in Epicoccum nigrum warrants reclassification into separate species.

Background Epicoccum nigrum Link (syn. E. purpurascens Ehrenb. ex Schlecht) is a saprophytic ascomycete distributed worldwide which colonizes a myriad of substrates. This fungus has been known as a biological control agent for plant pathogens and produces a variety of secondary metabolites with important biological activities as well as biotechnological application. E. nigrum produces darkly pigmented muriform conidia on short conidiophores on sporodochia and is a genotypically and phenotypically highly variable species. Since different isolates identified as E. nigrum have been evaluated as biological control agents and used for biocompound production, it is highly desirable that this species name refers to only one lineage. However, according to morphological and genetic variation, E. nigrum present two genotypes that may comprise more than one species.Methodology/Principal FindingsWe report the application of combined molecular (ITS and β-tubulin gene sequence analysis, PCR-RFLP and AFLP techniques), morphometric, physiological, genetic compatibility and recombination analysis to study the taxonomic relationships within an endophytic population that has been identified as E. nigrum. This combined analysis established two genotypes showing morphological, physiological and genetic divergence as well as genetic incompatibility characterized by colony inhibition, strongly indicating that these genotypes correspond to different species. Genotype 1 corresponds to E. nigrum while genotype 2 represents a new species, referred to in this study as Epicoccum sp.Conclusions/SignificanceThis research contributes to the knowledge of the Epicoccum genus and asserts that the classification of E. nigrum as a single variable species should be reassessed. In fact, based on the polyphasic approach we suggest the occurrence of cryptic species within E. nigrum and also that many of the sequences deposited as E. nigrum in GenBank and culture collection of microbial strains should be reclassified, including the reference strain CBS 161.73 sequenced in this work. In addition, this study provides valuable tools for differentiation of Epicoccum species.

Stachybotrys subreniformis, new from soil in China

A new species of Stachybotrys from soil in China, S. subreniformis, is illustrated and described. It differs from similar species mainly by producing smaller conidia and shorter conidiophores. The type specimen (dried culture) and living culture are deposited in the Plant Pathology Herbarium of Guizhou University (HGUP).

An unusual method of development and sporulation of Colletotrichum gloeosporioides on castor leaf – an SEM account

Development and sporogenesis of Colletotrichum gloeosporioides on castor leaf differed from that on other known host plants. C. gloeosporioides had three kinds of hyphae on castor leaf: primary infection hyphae (PIH), runner hyphae (RH) and secondary infection hyphae (SIH). The PIH originated from conidia, grew on leaf surface and entered the leaf by direct penetration of the cuticle without forming appressoria. The RH were sub-cuticular hyphae, the track of which was traceable by the bulgings on the leaf surface, and the SIH were the hyphae that emerged to leaf surface from RH through the cuticle or stomata. Conidia were initiated as small protrusions along the lengths of RH and SIH that got differentiated into distinct conidia, each born on a short stumpy conidiophore without forming any congregation. The protrusions from RH emerged to the leaf surface by piercing the cuticle, and they developed into distinct conidia on the leaf surface. The conidia developed from RH and SIH were identical in size and shape. Even though conidia were occasionally found emerged through stomata, that appeared to be random than a preferred route for the discharge of conidia. The penetration and sporogenesis of C. gloeosporioides on castor leaf differed from that reported on mulberry leaf.