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经紫外扫描分析,在PbGV较敏感的250～270nm波长范围内,黑色素与黑染料对紫外线的阻挡作用较强,其中前者的作用又比后者约强一倍。生物测定的结果表明,在PbGV包涵体悬浮液中加入0.006％(W/V)的黑色素或0.012％(W/V)的黑染料,能获得与病死虫匀浆稀释液相似的抗紫外辐射能力,可供实际防治菜粉蝶幼虫时使用。大菜粉蝶颗粒体病毒(PbGV)可有效地防治菜粉蝶(Pieris rapae)与大菜粉蝶(Pieris brassicae)幼虫,但提纯的病毒包涵体对紫外线较敏感。据报导,在真菌、细菌、原生动物、病毒等昆虫主要病原物类群中,颗粒体病毒对紫外线的抵抗性是最弱的(Sutter et al., 1977)。大菜粉蝶颗粒体病毒经波长为250～270nm的紫外线(0.37×10~4uw-秒/[cm~2])照射可被显著钝化(David,1969),在阳光直射下,病毒包涵体的水悬液经3小时后感染力明显下降,12～19小时后完全失活(David et al., 1968)。因此,在病毒包涵体悬浮液中加入保护剂,增强对紫外线的抵抗能力,延长病毒在田间的残效期以提高和保证防治效果是十分必要的。 David(1978)报导,在PbGV包涵体悬浮液中加入0.01％(W/V)的明胶和1％(V/V)的寄主血淋巴对病毒有显著的保护作用,如再加入0.01％的黑色素,则这种保护作用可进一步增强。由于寄主血淋巴难以大量获取,黑色素价格较昂贵,在生产上应用均受到一定限制,有必要加以改进。为此,我们进行了本试验。
UV-scan analysis shows that the UV-blocking effect of melanin and black dye is stronger in the wavelength range of 250 ~ 270nm where PbGV is more sensitive, and the effect of the former is about double that of the latter. Bioassay results showed that addition of 0.006% (W / V) melanin or 0.012% (W / V) black dye to the PbGV inclusion body suspension yielded similar UV-radiation resistance , For the actual control of cabbage butterfly larvae use. Pieris rapae and Pieris brassicae larvae can be effectively controlled by PbGV, but the purified virus inclusion body is sensitive to UV light. It has been reported that PMV is the weakest in ultraviolet light resistance among the major insect pathogenic groups of fungi, bacteria, protozoa and viruses (Sutter et al., 1977). Cabbage butterfly virus could be significantly inactivated by exposure to ultraviolet light (0.37 × 10 ~ 4uw-sec / [cm ~ 2]) with a wavelength of 250 ~ 270nm (David, 1969). Under direct sunlight, Susceptibility of the suspension decreased significantly after 3 hours and completely inactivated after 12 to 19 hours (David et al., 1968). Therefore, it is necessary to add the protective agent to the virus inclusion body suspension to enhance the resistance to ultraviolet light, prolong the residual period of the virus in the field so as to enhance and ensure the prevention and control effect. David (1978) reported that the addition of 0.01% (w / v) gelatin and 1% (v / v) host hemolymph to the PbGV inclusion body suspension significantly protected the virus from adding 0.01% melanin , This protection can be further enhanced. Due to the host hemolymph is difficult to obtain a large number of melanin prices are more expensive in the production of applications are subject to certain restrictions, it is necessary to be improved. To this end, we conducted this experiment.