• The Plant Pathology Journal
• /
• v.34 no.5
• /
• pp.367-380
• /
• 2018

Stems and pods of hyacinth bean cultivated in a farmer's field in Gazipur District, Bangladesh, were found rotted in nearly 5% hyacinth bean plants. A fungus having fluffy mycelium and large sclerotia was isolated from affected tissues. Combined results of morphological, molecular and pathological analyses identified the fungus as Sclerotinia sclerotiorum (Lib) de Bary. Inoculating the fungus on healthy hyacinth bean plants and pods reproduced the symptoms previously observed in the field. The three isolates obtained from naturally infected plants were cross inoculated in hyacinth bean, okra and African-American marigold and they were pathogenic to these hosts. The optimum temperature and pH for its growth were $20^{\circ}C$ and pH 5.0, respectively. Sclerotial development was favored at pH 5.0. Sucrose and mannitol were the best carbon sources to support hyphal growth, while glucose was the most favourable for sclerotial development. The hyacinth bean genotypes, HB-82 (Rupban Sheem) and HB-102 were found highly resistant, while HB-94 (Ashina) was moderate resistant to the fungus. Finally, S. sclerotiorum was sensitive to Bavistin, Dithane M-45 and Rovral fungicides and Ca in the form of $CaCl_2$. This observation could possibly aid in eliminating field loss in hyacinth bean caused by an emerging pathogenic fungus S. sclerotiorum.

• Korean Journal of Pharmacognosy
• /
• v.4 no.1
• /
• pp.23-27
• /
• 1973

Korean ergot sclerotia which were collected from Agropyron semicostatum $N_{EES}$, Miscanthus sinensis $A_NDERS$ var. purpurascens $R_{END}$, M. sacchariflorus $B_{ENTH}$. et HOOK,. M. sinensis $A_{NDERS}$., Eulalia speciosa $O.{\;}K_{UNTZ}$, Themeda triandra $F_{ORSK}$. var. japonica $M_{AKINO}$, and Phalaris arundinacea L. were investigated for their alkaloid constituents. Quantitative determinations of alkaloids were carried out using a modified procedure of van $U_{RK}$ and $M_{ICHELON}-K_{ELLEHER}$ methods. The results showed that the two ergots from Agropyron semicostatum and Phalaris arundinacea contained total alkaloids up to 0.137 per cent. The alkaloids of these two ergots are mostly water-insoluble alkaloids. The ergots parasitizing Reed Canary grass was found to contain both water-soluble and water-insoluble alkaloids. The TLC and PPC tests for the ergot alkaloids from Agropyron semicostatum and Phalaris arundinacea revealed that they contain at least two alkaloids, respectively, and that the ergot from Themeda triandra $F_{ORSK}$. var. japonica has one. The lipid contents of the seven ergots ranged from 13 to 29 per cent.

• The Plant Pathology Journal
• /
• v.22 no.2
• /
• pp.107-114
• /
• 2006

The white cottony stem rot pathogen Sclerotinia scierotiorum was subjected to 70 different isolates of actinomycetes indigenous to Jordan as biological control agents. Forty of them demonstrated chitinase activity on crab shell chitin agay (CCA) media and they were segregated into three groups: 14 highly active, 12 moderately active, and 14 with low activity, with average clearing zones of (4.7-8.3), (3.7-4.3), and (2.3-3.3) mm surrounding colonies on CCA, respectively. Further, these isolates were able to inhibit radial mycelium growth of the pathogen and were categorized into three antagonistic groups: 13 strong, 13 moderate, and 14 weak antagonists, with antibiosis inhibition Bones of (32.0-45.7), (22.7-31.3), and (3.7-22.3) mm, respectively. High levels of chitinase activity of the isolates Ma3 (8.3 mm), Jul (7.7 mm), and Sa8 (7.7 mm) with their antagonistic activity against mycelium growth of 45.7, 44.3, and 40.7 mm were observed, respectively. These isolates exhibited fungicidal activity against sclevotia of S. sclerotiorum. On the other hand, isolates Na5, Aj3, and Aj2 that produced no chitinase showed fungistatic effect only.

• The Plant Pathology Journal
• /
• v.19 no.3
• /
• pp.184-187
• /
• 2003

Verticillium wilt was first observed in 2001 on potatoes (Solanum tuberosum) cv. Superior at Daegwallyong area, one of the major seed potato producing areas in Korea. The wilted potato plants showed typical symptoms including gradual yellowing and interveinal necrosis. There was discoloration in the vascular tissues of the infected stems which turned light brown. Fungal isolates from discolored vascular tissues were whitish to creamy with folding on potato dextrose agar medium, where they used to produce resting dark mycelia but no micro-sclerotia. Conidiophores were septate with side branches, swelled at the base, and arranged in a whorl. Conidia were 2.5-11.2$\times$2.0-4.5 $\mu\textrm{m}$ um in size and were borne in small clusters at the tips of phialides. Optimal temperature range for mycelial growth was $25-30^{\circ}C$. Based on these cultural and morphological characteristics, the fungus was identified as Verticillium albo-atrum Reink & Berth. Pathogenicity tests by root dipping method revealed that the fungus caused the same symptoms as observed in naturally infected potato plants. This is the first report of Verticillium wilt on potato caused by Verticillium albo-atrum in Korea.

• The Plant Pathology Journal
• /
• v.18 no.3
• /
• pp.161-164
• /
• 2002

Colletotrichum musae was isolated from dark-brown anthracnose lesions on commercial banana (Musa sapientum L.) to establish the causal agent of the symptom. The fungus grew fast and produced white aerial mycelium on PDA. Acervuli developed abundantly on culture plates after incubation for 10 days at $25^{\circ}C$. Pinkish conidial masses were produced on the acervuli, which mostly coalesced together, Conidia were aseptate, hyaline, straight, ellipsoid to globose, and 14.5$\times$6.9 $\mu\textrm{m}$ in size. Black, clavate, round, or irregular-shaped appressoria measuring 8.8$\times$6.8 $\mu\textrm{m}$ were readily formed from germ tubes. Setae-like structures were not found either on the lesion or on the cultures. Sclerotia were also absent. Among the media, PDA medium was the best for mycelial growth. The optimum temperature for mycelial growth was $28^{\circ}C$, while the optimum pH ranged from pH 5.5 to 6.5. The isolates of C musae caused black necrotic lesions on banana fruits by needle-wound inoculation, and orange-colored spore masses were produced on the lesions. The fungus also caused discoloration on apple fruits inoculated.

• The Plant Pathology Journal
• /
• v.20 no.1
• /
• pp.75-80
• /
• 2004

In an attempt to develop effective biocontrol system for management of stem rot disease in groundnut, 57 bacterial isolates and 13 isolates of Trichoderma spp. were evaluated for their antagonistic activity against Sclerotium rolfsii. The antagonists were selected based on their ability to inhibit the external growth of S. rolfsii from infected groundnut seeds. Four isolates of Pseudomonas fluorescens, GB 4, GB 8, GB 10 and GB 27, and T. viride pq 1 were identified as potent antagonists of S. rolfsii. T. viride pq 1 produced extracellular chitinase and parasitized the mycelium of S. rolfsii. Under controlled environment conditions, P. fluorescens GB 10, GB 27, T. viride pq 1 and the systemic fungicide Thiram(equation omitted) reduced the mortality of S. rolfsii inoculated to groundnut seedlings by 58.0％, 55.9％, 70.0％ and 25.9％, respectively compared to control. In vitro growth of P. fluorescens GB 10 and GB 27 was compatible with T. viride pq 1 and Thiram(equation omitted). Integrated use of these two bacterial isolates with T. viride pq 1 or Thiram(equation omitted) improved their biocontrol efficacy. Combined application of either GB 10 or GB 27 with T. viride pq 1 was significantly effective than that with Thiram(equation omitted) in protecting groundnut seedlings from stem rot infection.

• Korean journal of applied entomology
• /
• v.9 no.1
• /
• pp.49-51
• /
• 1970

1. Claviceps species or Graminaceae were investigated from Kyonggi-Do Korea including Kwang-neung, Anseung, Pyongtack, Chingpyong Yichun and Suwon from June to November, 1969. 2. Sclerotia of Claviceps species were collected from 16 species of Graminaceae consisted of 11 genera. 3. New hosts of Claviceps species including 15 species in 10 genera were reported in Korea, 4. Claviceps pucilla Ces. on Themeda riandra FORSK. var. japonica M. was recorded in addition to Claviceps purpurea (Fr.) Tul. 5. Claviceps Purpurea (FR.) Tul. on Miscanthus Sinensis ANDERS occured at 449m above sea level near Suwon.

• Mycobiology
• /
• v.30 no.2
• /
• pp.65-69
• /
• 2002

Sclerotial development of Grifola umbellata(Pers. : Fr.) Donk was investigated through microscopic examinations. The sclerotium of G. umbellata was bumpy and rugged, multi-branched, and dark-brown to black in color. The sclerotial development of G. umbellata was categorized into three stages such as sclerotial initial, development and maturation. Sclerotium development was initiated as the white fungal mass. The superficial part of white sclerotium changed into gray, light brown and then black as its development proceeded further. As a distinctive characteristic of this fungus, a large number of crystals were observed in the medulla layer of sclerotium during its maturation. For development of new sclerotium, G. umbellata formed a white sclerotial primordium on the matured sclerotium. Development of sclerotium in G. umbellata was intimately associated with rhizomorphs of Armillariella mellea and the developing sclerotia were often penetrated by rhizomorphs of A. mellea into medulla layer.

• Proceedings of the Botanical Society of Korea Conference
• /
• 1987.07a
• /
• pp.157-167
• /
• 1987

The have been many reports that phenoloxidase are correlated with development in many fungi. C. congregatus, one of nushroom-forming basidiomycetes, which requires light for its development also has phenoloxidases. In C. congragatus, there are two sets of membrane-associated phenoloxidase (PHO I and PHO II) which are differentiated by their isozyme patterns, and each enzyme set consists of two different subtrate specific enzyme protein; o-tolidine reacting enzyme, and DOPA reacting enzyme. PHO I which is localized by a protoplast-concanavalin A technique by using a new solidifying agent, Pluronic Polyol F 127, instead of agar appears in the vegetative hyphae, and PHO II appears at the early primordial stage on agar and at the sclerotial stage of liquid shake cultures. Inhibition of PHO I with the enzyme inhibitors inhibits mushroom formation as well as melanization of the vegetative hyphae at concentrations which do not inhibit the vegetative growth. PHO I deficient mutants do not form mushrooms or melanins, and the mutants show abnormal nuclear migration patterns. PHO II has roles; possibly cementing the adjacent hyphae during the actual three dimensonal structure formation, and melanizing mushrooms and sclerotia. The possible roles of PHO I in the light reception complex and in melanin formation, the function of malanin, and possible roles of postulated post translational modifying enzymes which regulate the phenoloxidases, nuclear migration pattern, and self-nonself recognition mechanism are discussed.

• Mycobiology
• /
• v.48 no.4
• /
• pp.263-275
• /
• 2020

Phlebopus spongiosus is a well-known edible ectomycorrhizal mushroom indigenous to southern Vietnam. The mushroom specimens collected from northern Thailand in this study were identified as P. spongiosus. This identification was based on morphological characteristics and the multi-gene phylogenetic analyses. Pure cultures were isolated and the relevant suitable mycelial growth conditions were investigated. The results indicated that the fungal mycelia grew well on L-modified Melin-Norkans, and Murashige and Skoog agar all of which were adjusted to a pH of 5.0 at 30 ℃. Sclerotia-like structures were observed on cultures. The ability of this mushroom to produce fruiting bodies in the absence of a host plant was determined by employing a bag cultivation method. Fungal mycelia completely covered the cultivation substrate after 90-95 days following inoculation of mushroom spawn. Under the mushroom house conditions, the highest amount of primordial formation was observed after 10-15 days at a casing with soil:vermiculite (1:1, v/v). The primordia developed into a mature stage within one week. Moreover, identification of the cultivated fruiting bodies was confirmed by both morphological and molecular methods. This is the first record of P. spongiosus found in Thailand and its ability to form fruiting bodies without a host plant.