首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 593 毫秒
1.
Yasuo Suto 《Mycoscience》1999,40(6):509-516
A leaf spot disease called frosty mildew was observed onChaenomeles sinensis throughout Japan. Small brown spots with white tufts occurred followed by successive defoliation. On the fallen leaves, minute black dots are formed. The causal fungus was regarded as a new species ofMycosphaerella, M. chaenomelis, andCercosporella chaenomelis in anamorph. Pathogenicity of the fungus was confirmed only inC. sinensis by inoculation experiments. Colonies of the fungus grew well on potato sucrose agar, and grew at 10–30°C with an optimum temperature of 25°C. The fungus overwintered on the fallen diseased leaves in the form of pseudothecia, and ascospores served as the primary infection source from April to June.  相似文献   

2.
A needle blight disease with brown spots was found on ornamental trees ofPinus thunbergii in Shimane Prefecture, Japan. The causal fungus was identified asLecanosticta acicola, known as causal fungus of brown spot needle blight of pines recorded in the Americas, Europe, and China.Pinus thunbergii was heavily infected following inoculation with the fungus in June, but only slightly infected following inoculation in September. The mycelia of the fungus were raised and produced conidial masses on potato-dextrose and Waksman agars. They grew well at 20–25°C within the range of 5 to 35°C.  相似文献   

3.
Aphanomyces sp. was isolated from the carapaces of two juvenile soft-shelled turtles with fungal infections imported from Singapore. Their sizes were 2.9–3.5 cm in carapace length. Lesions with integumental necrosis and ulceration looked like white cotton. The fungus exhibited slow growth, hyphae were 7.5–15 μm in diam, coarse, and abundantly branched. Zoosporangia observed in the isolate were complex, its entire thallus being converted into zoosporangial units, with short or long lateral evacuation tubes, and isodiametric, 100–500 μm in length. Clusters of zoospores were also produced at the terminals of hyphae. The production of the primary zoospores was achlyoid. The primary encysted zoospores were spherical, 10–15 μm in diam. No sexual stages were observed on a hemp seed incubated in sterile tap water. The optimal temperature for the fungus was 30° C.  相似文献   

4.
Li S  Hartman GL  Jarvis BB  Tak H 《Mycopathologia》2002,154(1):41-49
As part of our effort to investigate fungi associated with soybean roots, Stachybotrys chartarum was isolated from soybean root lesions. Since this fungus has not been reported to cause a disease of soybean, the objectives were to identify and characterize this fungus using biological, chemical, and molecular approaches. Fungal morphology was examined using light and environmental scanning electron microscopy. Phialides bearing conidia arose from determinate, macronematous, dark olivaceous conidiophores. The phialides were obovate or ellipsoidal in whorls. Conidia were unicellular, round or ellipsoidal, 5–13 × 4–7 μm, initially hyaline with smooth walls then dark brown to black and rough-walled when mature. Radial growth of the fungus on cornmeal, oatmeal and potato dextrose agar was 38, 47, and 33 mm in diam., respectively, after 10 days at 25 °C. Pathogenicity was performed using sorghum grain colonized by S. chartarum placed below sown soybean seeds in a soil : sand (1 : 1) steam-pasteurized mix. Three weeks after inoculation, root lesions ranged from 7 to 25 mm long. The fungus was reisolated from soybean root lesions and was reidentified as S. chartarum. Biochemical analysis indicated that this soybean isolate produced satratoxins G and H along with roridin L-2, as well as the spircyclic lactones and lactams in rice culture. PCR using a S. chartarum-specific primer StacR3 and IT51 amplified a 198-bp DNA fragment from the total genomic DNA. The DNA sequence of the ITS region was 100% identical to the S. chartarum strain ATCC 9182, one nucleotide mismatch with S. chartarum strain UAMH 7900, and differed from all published sequences of 12 other species of Stachybotrys and 2 species of Memnoniella in GenBank with genetic divergence ranging from 5.26 to 9.98%. This molecular evidence further supports the identification of S. chartarum isolated from soybean root lesions. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

5.
A leaf spot and leaf blight disease was observed on Aloe vera plants as small, circular to oval dark brown necrotic sunken spots on leaves. Infected tissues collected from different sites in diseased fields were cultured on potato carrot agar medium, and the pathogen was identified as Alternaria alternata on the basis of morphological and cultural characteristics. The conidiophores were branched, straight, golden brown, smooth‐walled, measuring up to μm long by 3 μm wide with one conidial scar. The conidia were golden brown in colour and produced in long branched chains, obclavate in shape and in short conical flask. Pathogenicity tests conducted on healthy potted aloe plants in a glasshouse showed typical leaf spot symptoms after 4–7 days. The optimal temperature for the growth of A. alternata was 25°C.  相似文献   

6.
A leaf spot disease was observed on Mangifera indica L. located in the region of Rajkot, Gujarat, India. The symptoms included the appearance of small, circular to oval dark brown necrotic sunken spots on the leaves. The fungus formed grey to dark grey on potato dextrose agar and conidia were single‐celled, ovoid or oblong. On the basis of mycological characteristics, pathogenicity test and molecular identification using 28S rDNA sequence and internal transcribed spacer (ITS), the fungus was identified as Botryosphaeria dothidea. To the best of our knowledge, this is the first report of leaf spot on M. indica tree caused by Botryoshaeria dothidea in Gujarat, India.  相似文献   

7.
Lević J  Petrović T 《Mycopathologia》1997,140(3):149-155
The formation of conidia in Phaeocytostroma ambiguum on different media and conditions was investigated in this study. Carnation leaf agar (CLA) and a 12 h photoperiod (24/18 °C) provided excellent conditions for the promotion of rapid formation of both alpha (α) and beta (β) conidia in a number of P. ambiguum isolates. The dimensions of α- and β-conidia amounted to 6.0–19.6 × 3.8–7.5 μm and 6.0–24.9 × 1.1–2.6 μm, respectively. They were produced on short or elongate, simple and branched conidiophores. β-conidia have not been described before in P. ambiguum. Intermediate conidia were rarely found. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

8.
Adejumo  T.O.  Ikotun  T.  Florini  D.A. 《Mycopathologia》2001,150(2):85-90
Protomycopsis phaseoli (Ramak and Subram) is the causal agent of the cowpea leaf smut disease in Nigeria and not Entyloma vignae as claimed by some authors. This pathogen formed dark ash-grey to sooty-black lesions of 3–10 mm in diameter, while young lesions had yellow haloes. P. phaseoli produced dark reddish-brown chlamydospores that are globose to oval measured 23.8 μm, thick-walled and rugose. The chlamydospores germinated and produced globose vesicles. The pathogen grew on potato dextrose agar only when the leaf tissue was dipped in acidified water (1% H2SO4). The organism was slowly growing at 24–28 °C with snow white colour. Chlamydospores of P. phaseoli in infected cowpea leaves survived longer when buried in the soil for five months than when they were left on the soil surface for the same period at temperatures (26–27 °C) and humidity (70–82%) prevailing in Ibadan. Destruction of leaf debris before crop emergence, long period of rotation and no tillage cropping are suggested to prevent the onset and spread of leaf smut disease of cowpea. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

9.
Conidia of a new pathotype of Bipolaris zeicola (Stout) Shoemaker, which causes Helminthosporium corn leaf spot (HCLS) on inbreds derived from B73, are morphologically atypical on potato dextrose agar (PDA). The average conidial length on PDA (31.9 μm) is half that on naturally infected leaf (65.2 μm). Conidiogenuous cells terminally and subterminally located on short conidiophores produce new conidia which behave as initial conidia, i.e. they immediately elongate or germinate. Sometimes, they appear in chains. Based on conidial morphology on leaf materials and on wheat straw agar (WSA), the investigated fungus was identified as B. zeicola.  相似文献   

10.
Five isolates of a species of Colletotrichum were collected from Japanese barnyard millet (Echinochloa utilis) in Japan. Although the fungus had once been identi-fied as C. graminicola sensu lato, it was clearly different from C. graminicola isolated from maize (Zea mays) in its falcate and short conidia, 18.0–22.2 μm in length, cultural characteristics, and specific pathogenicity to E. utilis. Moreover, molecular phylogenetic analyses using sequences of rDNA-ITS, HMG, and SOD2 indicated a monophyly of the isolates. A new species, Colletotrichum echinochloae, is then proposed based on the morphological, pathological, and molecular characteristics.  相似文献   

11.
A new species,Stromatinia cryptomeriae, is described based on a specimen collected in Iwate Prefecture, Japan. It was found on fallen dead branches and twigs of Japanese cedar,Cryptomeria japonica. The morphology of isolates on potato-dextrose agar (PDA), which were obtained from single ascospores ofS. cryptomeriae, was identical withGloeosporidina cryptomeriae, the causal fungus of Japanese cedar twig blight. In an inoculation test using single ascospore isolates, many minute black spots (sclerotioid bodies; sclerotules) and acervuli ofG. cryptomeriae were formed on the necrotic lesions, which developed into typical symptoms of Japanese cedar twig blight. These results show thatStromatinia cryptomeriae is the teleomorph ofG. cryptomeriae. On PDA, the fungus grew over a range of about 1 to 25°C, with the optimum growth at about 15–20°C.  相似文献   

12.
A new species of Hirsutella, H. proturicola, isolated from a subterranean proturan (Baculentulus densus; Protura, Hexapoda), is described and illustrated. Hirsutella proturicola is characterized by producing monoblastic phialides of 24–51.5 × 2.5–5 μm with a slightly roughened neck, fusiform and curved conidia of 9–18 × 2.5–4 μm that have a truncate base and a papillate projection often capped with sheath-like mucilage, and pluricellular, globose to subglobose chlamydospores of 21–48 × 21–41.5 μm. This species is morphologically and phylogenetically close to H. rostrata, an acaropathogenic species, but can be distinguished from the size of the phialides and the size and shape of the conidia.  相似文献   

13.
Summary T. maculans inciting leaf spot of turmeric is difficult to be isolated into a pure culture. The best stage of the spot development on turmeric which yielded successful isolations was either the initial or the middle stage expressing yellowish necrotic areas. The successful course of development of asci, ascospore and conidia has been worked out. By streaking ascospore and conidial suspensions, the spot bearing portions of leaves on the inner side of the lid thus placing them in hanging position above the plates poured with cleared and acidified potato dextrose agar or turmeric leaf decoction agar or by streaking sterile water washings from the chocolate brown spots on these media, it was possible to isolate successfully the pathogenic culture ofT. maculans at 20° C.Condensed from the thesis submitted by the senior author to the University of Poona for M. Sc. (Agri.) under the guidance of the junior author. Respectively Assistant Professor of Plant Pathology, College of Agri. Poona and Wheat Rust Mycologist, Mahabaleshwar, India.  相似文献   

14.
Tomentella amyloapiculata and T. agbassaensis are described as new species within the genus Tomentella based on materials we collected in the West African, northern Guinean seasonal forests. We used a combination of anatomical characters, sequence analyses and phylogenetic inference of 71 ITS rDNA sequences to characterise the two new species. Anatomically, T. amyloapiculata is characterised by simple septate brown to dark brown, thick-walled subicular and subhymenial hyphae and triangular to slightly lobed brown basidiospores (in frontal view), with isolate aculei of 1–2 μm. Phylogenetically, T. amyloapiculata forms a sister species of T. fuscocinerea with a moderate bootstrap support of 70%. T. amyloapiculata deviates from T. fuscocinerea by 10.07–11.73% in their sequence similarities. As far as T. agbassaensis is concerned, it clusters phylogenetically together with T. bryophila with a strong bootstrap support of 99%. The species is characterised by slightly differentiated rhizomorphs with yellowish hyphae, clamped, thick-walled and yellow to dark yellow subicular hyphae and pale yellow, small basidiospores of 6–8(8.5) μm with aculei of up to 0.5 μm. Both new species deviated from each other by 11.0–11.60% with regard to the ITS rDNA nucleotides.  相似文献   

15.
Ascomata of a powdery mildew-like fungus have been found on Carpinus laxiflora in Tochigi Prefecture of Japan since 2003. The morphological and molecular characteristics of this fungus are reported, and a new species, Erysiphe fimbriata, is proposed. It has large chasmothecia (200–250 μm in diameter) with long (up to 4–5 mm in length), fimbriate appendages arising from the upper half of the chasmothecia and turning upward, and numerous asci (22–38 per chasmothecium). Erysiphe fimbriata is a unique fungus both genetically and morphologically.  相似文献   

16.
Queiroz  F.M.  de F.S. Muniz  M.  Menezes  M. 《Mycopathologia》2001,150(2):61-65
Alternaria brasiliensis sp. nov., was isolated from leaves of common bean, Phaseolus vulgaris L., showing punctiform non concentric leaf spots of brown color. Besides the symptomatological differences, the new Alternaria species presents distinct type of arrangement of conidia chain, body and beak size. The disease was observed in Montanha county, State of Espirito Santo, Brazil, but not yet reported in the literature. The causal agent of the disease is now described by the first time. The epithet used here is referring to the country where the species has been found. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

17.
In the summers of 2010 and 2011, an anthracnose disease was observed on the Jatropha curcas L. grown at the research field of Gyeongsangnam‐do Agricultural Research and Extension Services, South Korea. The symptoms included the appearance of dark brown spots on the leaf and fruit and the mummification of the fruit. The causal fungus formed grey to dark grey colony on potato dextrose agar. Conidia were single celled, ovoid or oblong, and 8–15 × 3–5 μm in size while seta was dark brown, cone‐shaped and 25–46 × 2–6 μm in size. The optimum temperature for growth was approximately 30°C. On the basis of mycological characteristics, pathogenicity test and molecular identification using internal transcribed spacer rDNA sequence, the fungus was identified as Colletotrichum gloeosporioides. To our knowledge, this is the first report of an anthracnose caused by C. gloeosporioides on J. curcas plant in Korea.  相似文献   

18.
Severe brown leaf spot disease was observed on Paris polyphylla var. chinensis in Sichuan Province, China, in 2017 and 2018. The initial symptoms were many light‐brown small spots with necrotic centres, round or irregular in shape, becoming dark brown, gradually enlarging and eventually coalescing, causing extensive leaf senescence. A fungus was isolated from diseased leaves showing typical symptoms of brown leaf spot. The isolates were cultured on potato sucrose agar, and their morphological characteristics of the causal pathogen were observed under a light microscope. Pathogenicity tests revealed that this fungus was the causal pathogen of the disease. Molecular analyses of the sequences of the ribosomal DNA internal transcribed spacer (ITS) region, translation elongation factor 1‐alpha (TEF) and the RNA polymerase II second largest subunit (RBP2) gene were conducted to confirm the identity of the pathogen. The multi‐gene phylogeny indicated that the causal agent was Alternaria tenuissima. To our knowledge, this is the first report of A. tenuissima causing brown leaf sports on P. polyphylla var. chinensis in China.  相似文献   

19.
A new shrimp-associated goby,Amblyeleotris melanocephala, is described on the basis of specimens from Okinoshima Island. Kochi Prefecture, and Okinawa Island, Okinawa Prefecture, Japan. The species is distinguished from other members of the genus by the following combination of characters: head dark brown, a few yellow spots on pectoral fin base and opercular margin, 13 second dorsal and 13 anal fin soft rays, 20 pectoral fin rays, longitudinal scales 92–101, proportional length of interpelvic connecting membrane relative to longest pelvic fin ray (CM-value) 0.46–0.55, presence of a ventral frenum, midline of nape naked, sides scaled above midpoint between preopercle and opercle.  相似文献   

20.
Phyllosticta tabernaemontanae, a leaf spot fungus isolated from the diseased leaves of Wrightia tinctoria, showed the production of taxol, an anticancer drug, on modified liquid medium (MID) and potato dextrose broth (PDB) medium in culture for the first time. The presence of taxol was confirmed by spectroscopic and chromatographic methods of analysis. The amount of taxol produced by this fungus was quantified using high performance liquid chromatography (HPLC). The maximum amount of taxol production was recorded in the fungus grown on MID medium (461 μg/L) followed by PDB medium (150 μg/L). The production rate was increased to 9.2 × 103 fold than that found in the culture broth of earlier reported fungus, Taxomyces andreanae. The results designate that P. tabernaemontanae is an excellent candidate for taxol production. The fungal taxol extracted also showed a strong cytotoxic activity in the in vitro culture of tested human cancer cells by apoptotic assay.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号