1. Nematode disease symptoms & signs of nematodes 1)Above ground symptoms a) Stunted growth b) Chlorosis and necrosis c) Incipient wilting d) Reduced plant stand e) Lesions on leaves f) Malformed floral parts, seed, leaves and stems

2. Nematode disease symptoms & signs of nematodes 2) Below ground symptoms a) Stunted or abbreviated roots b) Galls c) Lesions d) Rotted e) Abbreviations of tubers f) Hairy roots

3. Nematode disease symptoms & signs of nematodes 3) Signs of nematodes a) Cyst forms b) Egg masses c) Female nematodes in roots

4. 뿌리혹선충 암컷뿌리혹선충 피해

5. Secretory and excretory system 1.Function – removal of waste product (assumed to function in osmoregulation) 2. Forms 1) Tubular (Secernentea) - numerous cells - lateral excretory canals - terminal duct lined with cuticle 2) Glandular (Adenophorea) - single excretory gland cell - excretory duct – not lined with cuticle

6. Types of excretory system

7. Nematode development 1.Embryogenesis( 전배발생 ) 2.Post embryogenesis( 후배발생 ) 3.Gametogenesis( 배우자형성 )

8. 1.Embryogenesis ( 배발생 ) : 수정후 ~ first stage juvnile(J1) 1) Determinate cleavage 2) Nondeterminated cleavage 3) Meroblastic ( 부분할 ) 4) Holoblastic ( 전할 )

9. Egg laying

10. Egg embryogenesis

11. 2. Post embryogenesis( 후배발생 ) :J1 ~ adult :Genital primordium ( 생식계의 발생원기 )

12. Fourth molt of female

13. Fourth molt of male

14. 3. Gametogenesis : 배우자 형성 (male and female) 1) Males 2) Females 3) Hermaphrodite( 자웅동체 ) 4) Intersex( 간성 )

15. Female intersex: Morphologically appears as female, but exhibit secondary male characteristics, e.g., spicules or bursa (not functional) Ditylenchus triformis Male intersex: Morphologically appears as male, but exhibit secondary female characteristics, e.g., vulva or vagina (not functional) Meloidogyne javanica

16. Developmental characteristics of root-knot nematode

17. Nematode life cycle Egg J1J2 J3 J4 Male or female embryogenesis Molt1 Molt 2 Molt 3 Molt 4

18. Four types of reproduction 1) Amphimixis 2) Parthenogenesis 3) Automixis 4) Pseudofertilization

19. Amphimix (= Cross fertilization), 양성생식 : 암컷과 수컷의 교미 후 암컷의 난자와 수컷의 정자가 합쳐짐으로써 하나의 수정란이 형성되어 개체를 생성하는 생식법 Parthenogenesis, 단성생식 ( 처녀생식 ) : 암컷에서 생성된 난자가 수컷의 정자와의 수정 없이 홀로 발육하여 새로운 개체를 생성시키는 생식법

20. Automix (= Hermaphroditism, = self fertilization), 자가수정법 : 일반적으로 암컷의 형태를 한 선충이 동시에 난자와 정자를 모두 생성하여 자가수정을 통하여 개체를 생성한 생식법 Pseudofertilization (=Pseudogamy) : 정자가 난자를 뚫고 들어 가기는 하지만 난핵과 정핵의 합체는 이루어지지 않고 ( 유전적 합체가 없음 ), 난자가 홀로 단성생식 을 통해 새로운 개체 를 형성하는 방법. 정자는 단지 초기의 난자의 발육을 도모하기 위한 activator 역할을 한다.

21. Nematoda (Phylum) Secernentea ( 아강 ) 1)Phasmid present 2)Many celled excretory system 3)Usuallly one testis 4)Many eggs 5)Stomatostylet 6)Papilla on lips 7)Plant parasitic, animal parasitic nematodes Adenophorea ( 아강 ) 1) Phasmids absence 2) One-celled excretory system 3) Usually two testes 4) Few eggs 5) Odontostylet 6) Setae on lips 7) Marine nematodes, few plant, insect parasitic nematodes