Studies of ecological genetics of wing polymorphism of insects.

从环境因子和遗传基础两个方面对水稻害虫斑潜蝇和褐飞虱的迁徙多态进行了生态学研究。滴虫的飞行多态是由光周期决定的。它一年有三代，第二代成虫迁徙是众所周知的。秋季向西南方向移动。比较了3个世代对应的多态成虫的飞行活动和产卵前期。对应第2代的成虫比对应第1代的成虫有更高的飞行活动和更长的产卵前期。此外，与越冬世代相对应的成虫也具有迁徙特征。因此，越冬后羽化的成虫和第2代成虫一样也可能迁徙。褐飞虱具有翅型二型性、大胚芽和短小胚珠。这些遗传品系是通过15代以上的翅型选择而建立的。两品系杂交结果表明，翅型二型性的遗传基础不是简单的孟德尔遗传，而是多基因的，性状阈值假设的数量遗传模型较好地解释了杂交数据。与翅型相关的最小基因数估计为2.07个，实现遗传力估计为0.36个。成虫的颜色变化和对若虫发育的光周期敏感性也是可遗传的特征。这两个性状都是密度依赖的，翅的二形性也是如此。上述三个特征是相互关联的。因此，这三个性状可能受到JH激素等共同生理因素的调控，其遗传基础也可能是共同的。

Ecological studies on migratory polymorphism of rice pests, a skipper Parnara guttata and the small brown planthopper, Laodelphax striatellus were conducted in relation to the influence of environmental factors and genetical basis. P. guttata has flight polymorphisms which are determined by photoperiods. It has three generations a year and adults of the 2nd generation is well known to migrate. to south western direction in autumn. The flight activity and preoviposition perio were compared among the polymorphic adults which correspond to each of the 3 generations. The adults corresponding to the 2nd generation have higher flight activity and longer preoviposition period then those corresponding to the 1st generation. Furthermore, the adults which correspond to the overwintering generation also have the migrant traits. Therefore, the adults which emerge after hibernation may also migrate as well as the adults of the 2nd generation.The small brown planthopper L. striatellus has wing dimorphism, macroptery and brachyptery. The genetic strains were established by selection for wing forms for more than 15 generations. Crossing between the two strains showed that the genetic basis of the wing dimorphism is not a simple Mendelian but is polygenic, and the quantitative genetic model assuming the character threshold explained well the crossing data. The minimum number of genes concerning the wing form determination was estimated as 2.07, and the realized heritability for macroptery was estimated as 0.36. The color variations of adults and photoperiod sensitivity in terms of nymphal development were also heritable characters. Both characters varied density-dependently as well as the wing dimorphism did. The three characters as mentioned above correlated each other. Therefore, the three characters are supposed to be regulated by a common physiological factors such as JH hormone and genetic basis of them also are supposed to be common.