• The Plant Pathology Journal
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• 제32권4호
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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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• 제29권1호
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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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• 제24권2호
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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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• 제29권3호
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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.

• 한국응용곤충학회지
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• 제31권4호
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• pp.427-451
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• 1992

전국 국립공원 및 산지에서 154종의 수목을 대상으로 선충 종류 및 분포를 조사한 결과 수목과 관련이 있는 선충은 총 28속 73종이 밝혀졌다. Meloinema kerongens는 내장사 굴피나무, 느릅나무, 신나무에서 채집됨으로 새로운 기주식물로 밝혀졌다. 소나무재선충(Bursaphelenchus xylophilus)은 부산 금정산 일대에서만 발견되었고, 어리소나무재선충(B. mucronatus)은 제주도, 경남 마산, 진해 등지에서 발견되었고, 곤충기생성선충인 Prothallonema intermedium은 대구시 대덕산 리기다소나무, 제주도 제주시, 남원읍, 구좌읍, 애월읍 소나무에서 채집되었다. 수목별 기생선충 종류는 소나무가 32종으로 가장 많았고, 전나무 24종, 느티나무 20종, 감나무 19종, 상수리나무 18종 등의 순이었다. 선충종류별 분포지역은 Criconemella informis가 81지역에서 검출되어 가장 넓게 분포하고 있었으며, X. americanum 74, Tylenchorhynchus claytoni 51, C. macrodora 35, Hemicriconemoides varionodus, O. serratum이 31, Pararotylenchus pini 25, Hemicycliophora koreana 24, Aphelenchus avenae, C. pseudohercyniensis 22지역 등의 순으로 검출되었다.

• 한국응용곤충학회지
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• 제29권1호
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• pp.14-19
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• 1990

부산, 경남, 경북, 전남, 전북 22개 지역 19수종 238본의 고사목에서 1989년 4월부터 9월까지 선충류와 곤충류를 조사한 결과, 소나무 재선충은 부산지역에서만 검출되었으며, 어리소나무 재선충은 진주와 진해에서 분포가 확인되었다. 고사목에서 분리.동정된 선충류는 9속 13종이었으며 6속은 미동정되었다. 동정된 선충 중 Diplogasteroides dimidius, Rhabdontolaimus adephagus, R.janae, Mikoletzkya diluta, M. ruminis, m. langcauda, Parasitorhabditis hylurgi, Panagrolaimus concolor, Panagrodontus dentatus, Prothallonema intermedium, Macrolaimus canadensis는 우리나라 미기록종이다. 한편, 고산목에서 채집된 곤충은 5목 9과 25속 27종이었는데 딱정벌레목이 3과 19속 22종으로 가장 많았다. 그중 나무종이 10속 12종으로 빈번히 채집되었으며, Hypothenemus eruditus가 꽃싸리, 싸리, 조록싸리, 만리화, 닥나무에서 채집되어 새 기주로 추가되었다. 소나무 재선충의 매개충인 솔수염하늘소는 복부에서의 선충 검출수가 가장 많았으며, 성충 한마리당 선충 보유수는 최대 127,535마리, 최소 2,616마리, 정균 42,817마리였다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권1호
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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.