甜菜夜蛾细胞分裂期染色体的观察

以精巢组织为材料，采用空气干燥法制备染色体标本，对甜菜夜蛾Spodopteraexigua有丝分裂和减数分裂染色体形态行为进行了研究。结果表明：甜菜夜蛾的染色体数目为n=31；染色体为弥散着丝粒染色体，2条染色体上存在次缢痕；晚偶线期出现染色体互锁现象；从早粗线期到晚粗线期联会复合体逐渐伸长；终变期同源染色体形成环状、端部交叉、尾尾相对的结构。

Observations on mitotic and meiotic chromosomes of the beet armyworm, Spodoptera exigua Hübner (Lepidoptera: Noctuidae)

Chromosome preparations were made from testis tissue of the beet armyworm (Spodoptera exigua Hübner) with airdry method.The morphological characteristics and behaviors of the chromosomes at various phases of mitosis and meiosis were studied.The chromosome number of the beet armyworm was determined as n=31 All chromosomes have diffuse centromeres, and two chromosomes have secondary constriction.Chromosomes interlockings occur during the late zygotene.The synaptonemal complexes stretch gradually from the early pachytene to late pachytene.During the diakinesis the synaptonemal complexes showed rings, crossed or endto-end configurations.