转Bt基因棉花对烟粉虱天敌昆虫龟纹瓢虫的影响

Effects of Bt-cotton on Propylea japonica,an Enemy Insect of Bemisia tabaci (Gennadius)

在实验室控制条件下,以转Bt基因棉花GK12、33B、SGK321上的烟粉虱为食料饲养龟纹瓢虫,研究转Bt基因棉花上的烟粉虱对龟纹瓢虫生长发育及捕食的影响,同时利用Y型嗅觉仪,观察龟纹瓢虫对来自不同类型棉花的棉叶及其烟粉虱的嗅觉反应和视觉反应。结果表明,转Bt基因棉花和对应的常规棉亲本上的烟粉虱对龟纹瓢虫的发育历期和存活率没有明显的影响。龟纹瓢虫对棉花叶片、烟粉虱若虫、蜜露、蜕等4种物质的视觉反应之间没有明显的差异。对4种嗅源物质的嗅觉选择性的大小依次为:烟粉虱若虫>蜕>棉花>蜜露;在两类不同的棉花之间,龟纹瓢虫对GK12、33B、SGK321等3种转基因棉花上的烟粉虱若虫的嗅觉选择性明显较对应的常规棉亲本SM3、33、SY321上的烟粉虱若虫小;对烟粉虱若虫的蜕,两种转单价基因棉花GK12、33B较对应的常规棉亲本上的小,而转双价基因的棉花SGK321上与对应的常规棉之间没有明显的差异。烟粉虱密度大于200头/皿时,龟纹瓢虫捕食转基因棉花上烟粉虱的数量大于对应的常规棉花亲本,但烟粉虱密度小于200头/皿时,龟纹瓢虫捕食转基因棉花上烟粉虱的数量小于对应的常规棉花亲本。龟纹瓢虫对烟粉虱的捕食符合HollingⅡ型反应。龟纹瓢虫取食转基因棉花上的烟粉虱的理论极限值、瞬间攻击率均大于对应的常规棉亲本。

In a laboratory test, Bemisia tabaci on the plants of three transgenic Bt cotton cultivars （GK12, 33B, and SGK321） and their non-transgenic parents （ SM3, 33, and SY321 ） was used for feeding Propylea japonica. The effects of B. tabaci on the growth and predation of P. japonica were studied. Meanwhile, the olfactory and visual reactions of P. japonica to B. tabaci from the leaves of these transgenic and non-transgenic cotton plants were observed using a Y-shape olfactometer. The transgenic cotton plants and their non-transgenic cotton parents didn＇t produce significant effects on the developmental duration and survival of P. japonica. There was no significant difference in the visual reactions of P. japonica to cotton leaves, the nymph, honeydew, exuviates of B. tabaci. The olfactory reaction of P. japonica was descended in the order of nymph, exuviates, cotton plant, and honeydew. P. japonica on the three non-transgenic cotton plants had higher olfactory selectivity for the nymph of B. tabaci than those on the three transgenic cotton plants. P. japonica on the two univalent transgenic cotton plants of GK12 and 33B had lower olfactory selectivity for the exuviates of B. tabaci than those on their two non-transgenic cotton plants of GK12,33B. There was no difference in the olfactory selectivity for he exuviatesof B. tabaci on the bivalent transgenic cotton SGK321 and its non-transgenie parent SY321. When the prey density was greater than 200 head/dish, the amount of B. tabaci predated by P. japonica was higher on transgenie cotton plants than on non-transgenic cotton plants. When the prey density was lower than 200 head/dish, the amount of B. tabaci predated by P. japonica was higher on non-transgenic cotton plants than on transgenic cotton plants. The predation of P. japonica to B. tabaci was in conformity with Holling II type tabaci were significantly on transgenic cotton reaction. The theoretical limit and the instant attack rate of P. japonica on B plants than on their non-transgenic cotton plants