Studies of ecological genetics of wing polymorphism of insects.

研究了水稻害虫古塔塔和褐飞虱的迁移多态性与环境因素和遗传基础的关系。古塔木具有由光周期决定的飞行多态性。它一年有三代，第二代的成年鸟以迁徙而闻名。在秋天向西南方向。比较了3代多态成虫的飞行活性和产卵期。与1代相比，2代成虫具有更高的飞行活性和更长的产卵期。此外，越冬代所对应的成虫也具有迁徙特征。因此，冬眠后出现的成虫也可以像第二代成虫一样迁徙。小褐飞虱具有翅膀二态性、大翅型和短翅型。通过15代以上的翅型选择，建立了遗传品系。两个品系的杂交表明，羽翼二型现象的遗传基础不是简单的孟德尔遗传，而是多基因遗传，假设性状阈值的数量遗传模型很好地解释了杂交数据。与翅形决定有关的最小基因数估计为2.07，实现的大翅遗传力估计为0.36。成虫的颜色变化和光周期敏感性在若虫发育方面也是遗传性状。这两种性状都具有密度依赖性，翅膀二态性也具有密度依赖性。上述三个特征是相互关联的。因此，这三个性状应受JH激素等共同生理因素的调控，其遗传基础也应是共同的。

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.