Abstract
A study was made on the interstrain difference in dose-infection response and induction response of silkworm to the two strains of cytoplasmic polyhedrosis virus to obtain some informations on screening the leading strains. Comparison of dose-infection responses of larvae following the inoculation of the inclusion body of cytoplasmic polyhedrosis virus revealed that there is no significance in the resistance to dose-infection and any of strains were more resistant at advanced stage(4th instar) than younger stage(2nd instar). In the pathogenicity between cytoplasmic polyhedrosis virus with hexagonal and tetragonal outline, the hexagonal polyhedra showed higher pathogenicity than the tetragonal polyhedra. However, the averages of $LC_{50}$ of cytoplasmic polyhedrosis virus with hexagonal outline to larvae of parental inbred line were 6.12${\times}$10$\^$6//$m\ell$ at 2nd instar and 1.57${\times}$10$\^$7//$m\ell$ at 4th instar in spring and those to their hybrids were 1.28${\times}$10$\^$6//$m\ell$ at 2nd ins tar and 4.99${\times}$10$\^$6//$m\ell$ at 4th ins tar in autumn. Meanwhile the $LC_{50}$ averages of tetragonal polyhedra. to larvae of parental inbred line were 2.06${\times}$10$\^$7//$m\ell$ at 2nd instar and 5.67${\times}$10$\^$7//$m\ell$ at 4th instar in spring and those to their hybrids were 9.84${\times}$10$\^$6//$m\ell$ at 2nd instar and 3.86${\times}$10$\^$7//$m\ell$ at 4th instar in autumn, respectively. In comparison of induction response of silkworm larvae to inoculation of tetragonal polyhedra of cytoplasmic polyhedrosis virus, the induction rate of hexagonal polyhedra was remarkably higher in the treatment of inoculation at 2nd instar than at 4th instar and at the concentration of 1.3${\times}$10$\^$6//$m\ell$ than at any others. Most of induction showed a mixed infection with hexagonal and tetragonal polyhedra of cytoplasmic polyhedrosis virus.
세포질다각체 바이러스에 대한 가잠의 품종별 저항성과 이형 세포질다각체 바이러스 첨식에 의한 유발에 관한 시험을 한 결과는 다음과 같다. 1. 품종간의 저항성 1) 일본종 및 중국종 사이에 뚜렷한 차이가 없었다. 2) 장잠기(4령)가 추잠기(2령) 보다 저항성이 강했다. 3) 육각형 세포질다각체 바이러스가 사각형 세포질다각체 바이러스보다 병원성이 높았다. 4) 육각형 세포질다각체 바이러스의 LC$_{50}$의 평균치는 원종에서는 2령기잠 처리에서 6.12$\times$$10^{6}$/$m\ell$, 4령기잠 처리에서 1.57$\times$$10^{7}$ /$m\ell$ 이었고 교잡종에서는 2령기잠 처리에서 1.28$\times$$10^{6}$/$m\ell$, 4령기잠 처리에서 4.99$\times$$10^{6}$/$m\ell$이었다. 5) 사각형 세포질다각체 바이러스의 LC$_{50}$의 평균치는 원종에서는 2령기잠 처리에서 2.06$\times$$10^{7}$ /$m\ell$, 4령기나 처리에서 5.67$\times$$10^{7}$ /$m\ell$ 이었고 교잡종에서는 2령기잠 처리에서 9.84$\times$$10^{6}$/$m\ell$, 사령기잠 처리에서 3.86$\times$$10^{7}$ /$m\ell$이었다. 2. 이형 세포질다각체 바이러스 첨식에 의한 유발사각형 세포질다각체 바이러스 첨식에 의한 육각형 세포질다각체 바이러스의 유발은 1) 영기별로 볼 때 2령기잠 처리에서가 4영기잠 처리에서보다 월등히 높은 유발률을 보였다. 2) 유형별로 볼 때 대부분이 육각형과 사각형의 혼합감염 형태로 나타났다. 3) 농도별로 볼 때 대체로 1.3$\times$$10^{6}$/$m\ell$ 농도를 중심한 중간농도에서 높은 유발률을 나타냈다.타냈다.