Tylenchida

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Tylenchida
Superfamily Criconematoidea
Family Criconematidae (Criconemoides, Criconema)
Family Tylenchulidae
Superfamily Tylenchoidea
Family Tylenchidae (Tylenchulus)
Family Anguinidae (Anguina, Ditylenchus)
Family Dolichodoridae (Dolichodorus)
Family Belonolaimidae (Belonolaimus)
Family Pratylenchidae (Pratylenchus, Radopholus)
Family Hoplolaimidae (Hoplolaimus)
Family Heteroderidae (Meloidogyne, Heterodera)
Aphelenchida
Family Aphelenchidae (Aphlenchus)
Family Paraphlenchidae
Family Aphelenchoididae (Aphelenchoides,
Bursaphelenchus)
Family Senuridae
Family Entaphlenchidae
Criconemoides
(Ring nematode)
1.
2.
3.
4.
5.
Ectoparasitic nematode
Males rare
Unique cuticular marking: segmentation, spines
Shape of esophagus: Bowling pin
Difficult to extract by Bearmann method
because of nematode mobility
-Use centrifugal sugar floatation
(원심분리에 의한 설탕물 부유법)
Ring nematode
Aphlenchoides
(Bud and leaf nematode)
1. Diverse host group; Fungi, Insect, plant
2. Morphology
- Oval shape median bulb
- Slender body shape
- ♀ ; Monodelphic, prodelphic
♂ ; Monorchic, outstreched
- Mucro ; 꼬리끝에 형성된 돌기
3. A. besseyi (rice white tip nematode)
A. fragariae (strawberry nematode)
Aphlenchoides
• Aphelenchoides besseyi is best known as the
causal agent of white tip disease of rice. It is a
facultative ecto(생장점) - and endoparasite(엽육
조직) of the leaves and young tissues of rice,
the characteristic symptoms including
whitening of the top several centimeters of the
leaves, necrosis, distortion and crinkling of the
flag leaf. The nematode is seed borne and can
survive in a state of anhydrobiosis for several
years on stored grain, but much less under
field conditions.
Rice white tip disease
Busaphlenchus xylophilus
(pine wood nematode)
1. Pine wilt disease
2. First report in Japan
1905 : 일본 나가사끼 소나무좀류 피해로 오인,
1969 : 소나무재선충 판명
3. 국내-1957 : 전남 구례군 마산면 황전리 발생
4. 미국(1934), 프랑스(1979), 대만(1980), 중국(1982)
5. “소나무의 에이즈”
Distribution of pine wood nematode
Morphological distinction:
Spicule of males: large, uniquely curved, paired, with sharply
pointed prominent rostrum(돌기); distal ends of spicules with
typical disc-like expansions.
Female pine wood nematode
Male pine wood nematode
Pine sawyer (솔수염하늘소)
Feeding behavior
<소나무 재선충의 피해가 나타나는 과정>
- 재선충 침입 6일후 : 잎이 밑으로 처지기 시작
- 재선충 침입 20일후 : 잎이 시들기 시작
- 재선충 침입 30일후 : 잎이 급속하게 붉은색으로
변색 고사시작
* 재선충이 침입한 나무는 100% 고사
Damaged tree infected by Bursaphelenchus xylophilus
Aug. 20, 2003
Aug. 25, 2003
Sep. 3, 2003
Tree mortality caused by pinewood nematode
◈ Several organisms are involved in pine wilt disease. The nematode
Bursaphelenchus xylophilus is transported to the trees by Pinesawyer
beetles, and feed on Blue-stain fungi as well as cells lining the resin
canals of the tree. Bark beetles help to introduce the Blue-stain fungi
into the tree, allowing the nematodes to feed and multiply.
◈ During warm periods in the summer, the nematodes spread
throughout the tree and multiply very rapidly. As they destroy the resin
canal cells, the tree's water-moving system becomes clogged and
resin flow slows, then stops. Wilt symptoms develop and the tree dies.
(Life cycle; 30℃-3 days, 25℃-4~5일, 20℃-6일)
Disease cycle by Bursaphlenchus xylophilus
◈ Dead pines should be cut promptly and burned, buried
or chipped. Do not keep the wood for firewood. Wood chips
pose minimal risk of spreading pine wilt, but beetles will
continue to emerge from logs kept for firewood. Pinesawyer
beetles lay their eggs under the bark of the pine, and a new
generation emerges in the spring, ready to infect new pine
trees.
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