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为调查中华稻蝗Oxya chinensis的地理适应,自北纬42.3°至20.0°采集了5个地理种群的标本,比较了其子代的卵滞育发生、滞育强度及成虫虫体大小。结果表明:不同的中华稻蝗地理种群显示了不同的光周期和温度反应模式。铁岭、济宁和泗洪种群的滞育不受光周期和温度的影响,滞育率均为100%。南方的长沙和海口种群仅部分卵进入滞育,海口种群在短日条件下的滞育率高于长日条件,卵期温度亦对其滞育有较大的影响,而长沙种群的卵滞育仅受卵期温度的调控。长沙和海口种群的卵滞育强度最弱,其次是铁岭种群,中间纬度的济宁和泗洪种群的滞育强度最高。在北方的一化性种群中,滞育强度随着纬度的降低而增强。成虫的虫体大小因栖息地纬度的变化而呈现复杂的变异,北方种群的虫体大小与栖息地纬度存在显著的负相关关系,而长沙和海品种群的虫体小于济宁和泗洪种群。结果提示中华稻蝗各种群已形成各自的地理适应机制,纬度梯度在其生活史的形成和发育中起着重要的作用。
In order to investigate the geographical adaptation of Oxya chinensis, five geographical populations were collected from 42.3 ° north latitude to 20.0 ° north latitude. The incidence of diapause, diapause intensity and size of adult parasites of their offspring were compared. The results showed that different geographical populations of O. chinensis showed different photoperiod and temperature response patterns. The diapause of Tieling, Jining and Sihong populations was not affected by photoperiod and temperature, and the diapause rate was 100%. Only part of the eggs of Changsha and Haikou populations in the south entered diapause. The diapause rate of Haikou population in short-day conditions was higher than that of the long-day condition, and the egg temperature also had a significant impact on their diapause. Fertility is only regulated by the temperature of the egg. The diapause intensity of eggs was the weakest in Changsha and Haikou populations, followed by that of Tieling population. The diapause intensity of Jining and Sihong populations in the middle latitudes was the highest. In a monocentric population in the north, diapause intensity increases with latitude. The size of adult worms showed complicated variation due to the change of habitat latitude. There was a significant negative correlation between the size of insects and the latitude of habitats in northern populations, while the population of parasites in Changsha and sea breeds was less than that of Jining and Sihong populations. The results suggest that each group of O. chinensis has formed its own geographical adaptation mechanism, and latitude gradient plays an important role in the formation and development of its life history.