四种天牛的核型比较研究

为弄清天牛的核型特征， 补充我国天牛染色体分类特征和天牛细胞分类学的基础研究空缺， 本文以4种沟胫天牛亚科天牛为研究对象， 选取天牛的分裂旺盛组织精巢（卵巢）和中肠， 在不同的条件下进行天牛染色体玻片的制备和观察。结果显示： 4种天牛染色体数目均为 2n = 20， 性别决定机制为Xy_p。其中， 云斑白条天牛Batocera lineolata的核型公式： 4L+5M+Xy_p， 大型染色体4对， 中型染色体5对， 性染色体为小型； 榉白背粉天牛Olenecamptus cretaceus marginatus、 中华八星粉天牛Olenecamptus octopustulatus chinensis（粉天牛属）和桑天牛Apriona germari的核型公式均为： 5L+4M+Xy_p， 大型染色体5对， 中型染色体4对， 性染色体为中型。粉天牛属的榉白背粉天牛和中华八星粉天牛的核型指数非常相近； 桑天牛的染色体公式虽然与粉天牛属相同， 但长度和着丝粒位置明显不同。

A comparative study on karyotypes of four long-horned beetles (Coleoptera: Cerambycidae)

To make clear the characteristics of karyotypes of long-horned beetles, supplement the chromosome classification feature and fill up the basic research vacancy of cytotaxonomy about long-horned beetles, the tissues with exuberant differentiation (testis, ovary and midgut) of four species of Lamiinae beetles were chosen for preparing slides of chromosomes under different conditions. The results showed that their chromosomal number is 2n=20 and the sex-determining mechanism is Xy_p. The karyotype of Batocera lineolata is composed of 4 pairs of large autosomes, 5 pairs of medium sized autosomes and 1 pair of small sex-chromosome, and the karyotype formula is 4L+5M+Xy_p. For Apriona germari, Olenecamptus cretaceus marginatus and Olenecamptus octopustulatus chinensis, their karyotypes are all composed of 5 pairs of large autosomes, 4 pairs of medium sized autosomes and 1 pair of medium sized sex-chromosome, and the karyotype formula is 5L+4M+Xy_p. The two long-horned beetles of Olenecamptus have very similar karyotype index. The chromosome size and the centromere location among A. germari, B. lineolata and Olenecamptus are obviously different.