• The Plant Pathology Journal
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• v.32 no.4
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• pp.340-346
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• 2016

To understand how Bursaphelenchus xylophilus kills pine trees, the differences between the effects of B. xylophilus and B. mucronatus on pine trees are usually compared. In this study, the migration and attacking ability of a non-pathogenic B. mucronatus in Pinus thunbergii were investigated. The distribution of B. mucronatus and the number of dead epithelial cells resulting from inoculation were compared with those of the pathogenic B. xylophilus. Although B. mucronatus is non-pathogenic in pines, its distribution pattern in P. thunbergii was the same as that of B. xylophilus. We therefore concluded that the non-pathogenicity of B. mucronatus could not be attributed to its migration ability. The sparse and sporadic attacking pattern of B. mucronatus was also the same as that of B. xylophilus. However, the number and area of the dead epithelial cells in pine cuttings inoculated with B. mucronatus were smaller than in those cuttings inoculated with B. xylophilus, meaning that the attacking ability of B. mucronatus is weaker than that of B. xylophilus. Therefore, we concluded that the weaker attacking ability of B. mucronatus might be the factor responsible for the non-pathogenicity.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.116-122
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• 2013

To evaluate the mechanisms of pathogenicity and nonpathogenicity of Bursaphelenchus xylophilus and B. mucronatus isolated in South Korea, we used 4-year-old P. thunbergii seedlings and 20-cm long one-year-old stem cuttings of 5-year-old Pinus thunbergii, and studied distributions and multiplications of pine wood nematodes after inoculation. The distributions of B. xylophilus in the 20-cm pine stem cuttings were not significantly different from that of B. mucronatus. Conversely, the proliferation rate of B. xylophilus on mycelial mats of Botrytis cinerea was significantly different from that of B. mucronatus. The study using 4-year-old P. thunbergii seedlings also showed that B. mucronatus can migrate to distal portions of the pine seedlings the same as B. xylophilus, but the populations of B. xylophilus remaining in the pine seedlings were relatively larger than those of B. mucronatus. Therefore, we concluded that the pathogenicity of B. xylophilus could be strongly influenced by its ability to multiply.

• The Plant Pathology Journal
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• v.24 no.2
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• pp.159-163
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• 2008

Accurate identification of pine wood nematode, Bursaphelenchus xylophilus is a prerequisite to diagnose the pine wilt disease. However, a fungivorous nematode, B. mucronatus is highly similar to B. xylophilus and it is difficult to differentiate these two species by morphological features. A molecular diagnosis method, ITSRFLP was applied for the identification of B. xylophilus and B. mucronatus from Korea. Genomic DNA was extracted from a single individual nematode and ITS DNA was amplified by PCR. The size of PCR product was approximately 900bp and the sequence data were obtained after cloning. Amplified ITS was digested by 5 different restriction enzymes (Rsa I, Hae III, Msp I, Hinf I, and Alu I) and provided a discriminatory profile for B. xylophilus and B. mucronatus. Besides, B. mucro- natus was determined to have 2 different genotypes, East Asian type and European type also clearly separated by Rsa I and Hae III digestion. European type of B. mucronatus is recently collected from Pinus koraiensis and has not been reported before. ITS sequnce data were analyzed by Restriction Mapper program and the result supported ITS-RFLP pattern. These data indicated that PCRRFLP method is an accurate and simple way for identification of Bursaphelenchus species.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.344-349
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• 2013

Intraspecific variation in morphometry of pine wood nematodes Bursaphelenchus xylophilus and B. mucronatus in relation to geographical locations in South Korea was investigated using morphometric characters (body length, a, b and c ratio, stylet length, and spicule length for a male nematode and V (%) value for a female nematode). B. xylophilus was isolated from Pinus thunbergii in Jinju (1998), Ulsan (2000), Yangsan (2000), Mokpo (2001) and Jeju (2004), and from P. densiflora in Gumi (2001). B. mucronatus was isolated from P. thunbergii in Jinju (1991) and from P. densiflora in Milyang (2001). The body length of male and female B. xylophilus had the highest coefficient of variability and showed significant differences among geographical locations. The V (%) value for female B. xylophilus showed the lowest coefficient of variability, changing little with geographical area and host plant. All morphometric characters in B. mucronatus except for stylet length and female body length showed no significant differences between locations or hosts, suggesting they may not be affected by geographical area or host plant.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.427-451
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• 1992

The nematodes associated with forest trees were surveyed in the National Parks and Mountains in Korea. A total of 73 species on 28 genera were identified from rhizosphere of 154 tree s species. Platycarya strobilacea, Ulmus davidiana and Acer ginnala were known to new host p plants of Meloinema kerongens. Bursaphelenchus xylophilus was detected only in Pusan on Pi$\pi$us t thunbergii, B. mucronatus was detected in Cheju, Masan, and Chinhae. Insect parasitic nemat todes, Prothallonema intermedium, on P. rigida in Daegu, P. thunbergii in Cheju city, Namwonu up, Gujoa-up and Aewol-up. The number of nematode species according to forest trees was t the highest on P. thunbergii to 32 species, followed by 24 species on Abies holophylla, 20 species on Zelkova serrata, 19 species on Diospyros kaki, 18 species on Quercus acutissima, respectively. L Localities of distribution according to nematode species were as follows; Crico$\pi$emella i$\pi$formis i in 81, X. americanum in 74, Tylenchorhynchus claytoni in 51, C. macrodora in 35, H Hemicriconemoides varionodus and Ogma serratum in 31, Pararotylenchus pini in 25, H Hemicycliophora koreana in 24, Aphelenchus avenae and C. pseudohercyniensis in 24, respectively.

• Korean journal of applied entomology
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• v.29 no.1
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• pp.14-19
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• 1990

Nematodes and insects associated with dead trees were surveyed on the 238 dead trees belonging to 19 tree species in Pusan, Gyeongnam, Gyeongbuk, Chunnam, and Chonbuk provinces from April to September of 1989. Pine wood nematode, Bursaphelenchus xylophilus was found only in Pusan but B. mucronatus was collected at Chinju and Chinhae. The 13 nematode species in 9 genera were identified. Out of them, Diplogasteroides dimidius, Rhabdontolaimus adephagus, R. janae, Mikoletzkya diluta, M. ruminis, M. langcaudaa, Parasitorhabditis hylurgi, Panagrolaimus concolor, Panagrodontus dentatus, Prothalonema intermedium, and marcrolaimus canadensis were recorded for the first time in Korea. Insects collected from dead trees were 5 orders, 9 families, 25 genera, and 27 species. of them, the Coleoptera were the most collected insects by the 3 families, 19 genera and 22 species. The Scolytidae were 12 species in 10 genera. Hypothenemus eruditus was firstly collected from Campylotropis macrocarpa, Lespedeza maximowizi, Forsythia ovata, Meliosma oldhami, Securinega suffruticosa, Broussonetia kazinoki, and Cornus walteri. The maximum number of pine wood nematode was separated from the abdomen of Monchamus alternatus, the pine woodnematode vector. The maximum number of nematodes per an adult of M. alternatus was 127,535, minimum 2,616, and average 42,817.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.104-115
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• 2003

A series of experiments was carried out to determine the possibility for the non-ionic surfactant (NIS) as a feed additive for ruminant animals. The effect of the NIS on (1) the enzyme distribution in the rumen fluids of Hereford bulls, (2) the growth of pure culture of rumen bacteria and (3) rumen anaerobic fungi, (4) the ruminal fermentation characteristics of Korean native cattle (Hanwoo), and (5) the performances of Holstein dairy cows were investigated. When NIS was added to rumen fluid at the level of 0.05 and 0.1% (v/v), the total and specific activities of cell-free enzymes were significantly (p<0.01) increased, but those of cell-bound enzymes were slightly decreased, but not statistically significant. The growth rates of ruminal noncellulolytic species (Ruminobacter amylophilus, Megasphaera elsdenii, Prevotella ruminicola and Selenomonas ruminantium) were significantly (p<0.01) increased by the addition of NIS at both concentrations tested. However, the growth rate of ruminal cellulolytic bacteria (Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefaciens and Butyrivibrio fibrisolvens) were slightly increased or not affected by the NIS. In general, NIS appears to effect Gram-negative bacteria more than Gram-positive bacteria; and non-cellulolytic bacteria more than cellulolytic bacteria. The growth rates of ruminal monocentric fungi (Neocallimastix patriciarum and Piromyces communis) and polycentric fungi (Orpinomyces joyonii and Anaeromyces mucronatus) were also significantly (p<0.01) increased by the addition of NIS at all concentrations tested. When NIS was administrated to the rumen of Hanwoo, Total VFA and ammonia-N concentrations, the microbial cell growth rate, CMCase and xylanase activities in the rumen increased with statistical difference (p<0.01), but NIS administration did not affect at the time of 0 and 9 h post-feeding. Addition of NIS to TMR resulted in increased TMR intake and increased milk production by Holstein cows and decreased body condition scores. The NEFA and corticoid concentrations in the blood were lowered by the addition of NIS. These results indicated that the addition of NIS may greatly stimulate the release of some kinds of enzymes from microbial cells, and stimulate the growth rates of a range of anaerobic ruminal microorganisms, and also stimulate the rumen fermentation characteristics and animal performances. Our data indicates potential uses of the NIS as a feed additive for ruminant animals.