四种天牛的核型比较研究

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

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Xyp。其中,云斑白条天牛Batocera lineolata的核型公式:4L+5M+Xyp,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+Xyp,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。

To make clear the characteristics of karyotypes of long-homed beetles, supplement the chromosome classification feature and fill up the basic research vacancy of cytotaxonomy about long- homed 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 Xyp. 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 ＋ Xyp. 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 ＋ Xyp. The two long-homed 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.