• Mycobiology
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• v.32 no.4
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• pp.197-198
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• 2004

A new technique for single spore isolation was developed for predacious fungi forming constricting rings directly on the spores using Dactylaria brochopaga and Arthrobotrys dactyloides. Constricting rings were induced directly on the spores by transferring the spores in 25 ppm solution of DL-Valine in sterile distilled water. Freshly hatched and thoroughly washed second stage juveniles of Meloidogyne incognita were transferred into cavity blocks containing induced rings for trapping and killing of nematodes. The killed nematodes were surface sterilized with streptomycin and inoculated into petri dishes containing maize meal agar media with 100 ppm streptomycin. The petri dishes were incubated at $29{\pm}1^{\circ}C$ for few days which yielded axenic culture of these fungi.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.63-68
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• 2008

Strain Kan-23 was extracted from nematophagous fungi, which were isolated from the soil sample of oriental melon field. The strain exhibited the slow-growing characteristic forming conidia after prolonged incubation for 30 days. Morphological features of strain Kan-23 were observed under scanning electron microscope (SEM). It possesses erect conidiophores which contain $2{\sim}3$ side branches, with each branch producing $5{\sim}10$ conidia. The size of conidiophores were between $160{\sim}450\;{\mu}m$. Conidia were ellipsoidal with three septa[septum] in each conidium. Strain Kan-23 captured nematodes by means of giant constricting rings, which were observed in the glucose peptone agar medium. ITS region of rDNA sequence was analyzed. On the basis of the high sequence similarity of ITS region (99%), the Kan-23 strain was closely related to Drechslerella brochopaga (U51950). This is the first report on Drechslerella brochopaga as a nematophagous fungus in Korea.

• Applied Biological Chemistry
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• v.50 no.2
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• pp.101-106
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• 2007

Twenty-two strains of nematophagous fungi were isolated from 100 soil samples. Nematophagous fungi were classified into three categories; 3-dimensional adhesive nets (A group), 2-dimensional adhesive nets (B group) and constricting ring (C group). Nine strains were selected and identified on the basis of morphological characteristics (hypha, conidiophore, form and size of conidia, number of conidia, node of conidophore, number and location of septa, size and color of chlamydospore) and ITS (internal transcribed spacer) region of rDNA sequences. As the results, the isolated were identified as belonging to the species of Monacrosporium thaumasium (Kan-2, Kan-4, Kan-11), Arthrobotrys oligospora (Kan-9, Kan-13, Kan-20, Kan-21), A. musiformis (Kan-12), and A. dactyloides (Kan-22).

• Mycobiology
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• v.33 no.4
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• pp.215-222
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• 2005

Variability in growth and sporulation of five isolates of Arthrobotrys dactyloides was studied on five agar, 6 bran and 5 grain media. Potato dextrose agar (PDA) supported maximum growth of isolate A, C and E, while growth of isolate Band D was significantly lower on this medium. On Czapek's agar and yeast glucose agar media the differentiation in the isolates in relation to growth was poor than PDA. The other two media showed much poorer differentiation. On Czapek's agar medium, sporulation was recorded in isolate B only, whereas other isolates showed rare sporulation. Among the bran media, pea bran agar medium supported maximum growth of all the isolates except isolate B. Gram and rice bran agar media were next best. However, the growth of isolate B on the gram bran agar medium was more or less equal as other isolates. On pigeon pea bran agar medium, isolate E failed to grow while other isolates recorded poor growth. On lentil bran agar medium, only isolate Band D recorded little growth, whereas other isolates failed to grow. All the isolates recorded good sporulation on bran agar media except pigeon pea and lentil bran agar media. The grain agar media supported moderate to very good growth of all the isolates. In general isolate B remained slow growing on these media except gram grain and sorghum grain agar media on which growth of this isolate was comparable to other isolates. Sporulation in general, was good on all the grain agar media. Among different substrates screened, barley grain and pea bran were found superior to others for mass culture of isolate A of A. dactyloides.

• The Korean Journal of Mycology
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• v.29 no.2
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• pp.123-126
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• 2001

A survey of 43 soil samples collected from southern Korea has shown that nematophagous fungi occurred in a variety of habitats. Nine predatory and two endoparasitic species were isolated. Habitats were classified into four types, i. e., mountain, upland, paddy field and greenhouse. Of these, greenhouse and upland had the highest incidence of nematophagous fungi $(95{\sim}100%)$ compared with mountain (37.5%) and paddy field (16.7%). The most common species was Arthrobotrys oligospora Fres., which was isolated from 25.5% of soil samples. Net forming species were the most abundant (72.5%), followed by constricting ring (10.0%), adhesive hyphae (7.8%), endoparasitic fungi (5.0%), and adhesive knob (4.8%). Nematophagous fungi were isolated move frequently from cultivated soil rather than uncultivated mountainous soil.

• Research in Plant Disease
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• v.25 no.3
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• pp.149-155
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• 2019

Nematode-trapping fungi develop trap and consume nematodes are an important part of the subsoil ecosystem and they share a special predator-prey relationship. Four nematode-trapping species, there with adhesive network, Arthrobotrys oligospora, A. sinensis, A. thaumasia and one with constricting ring, Drechslerella brochopaga were collected from soils in Korea and tested their predacity against 12 different nematode species. They were three feeding groups, plant-parasitic (Meloidogyne incognita and Pratylenchus penetrans), fungivorous (Aphelenchus avenae), bacteriovorous (Betlerius sp. and Diplogasteritus sp. in diplogasterid, Panagrolaimus labiatus, P. multidentatus in panagrolaimid, Mesorhabditis irregularis, Pelodera strongyloides and Rhabditis sp., in rhabditid, and Acrobeloides sp. in cephalobid). Results showed that nematode-trapping fungi successfully captured most of nematodes in Petri dish in the group of plant-parasitic nematodes and rhabditids, moderately and variably in other nematodes in 15 days. But it didn't captured A. avenae and Acrobeloides sp. both belongs to c-p group 2. Numbers of Acrobeloides sp. and A. avenae even increased during the test period. The results of this study indicated that nematode-trapping fungi may have specificity among nematode species.