四十五种叶蝉的染色体研究（同翅目：叶蝉总科）

研究观察了45种中国雄性叶蝉的减数分裂，其中44种的核型为首次报道，染色体数目变化在2n=12～26之间，性别决定均为XO型。从叶蝉总科的组型图来看，该科染色体数目变化在2n=8～28之间，峰值为2n=18(16+XO)，另外几种类型2n=16，20，22也有较高的出现频率。科内染色体数目的进化不具有明显的方向性，2n=22(20+XO)是该科的原始核型，易位导致的不均等互换可能是染色体数目进化的主要机制。从精子发生来看叶蝉总科与角蝉总科的关系较为密切，两者的共同特点是：①精母细胞体积较大，显著不同于沫蝉和蝉科；②减数分裂行为及精子变态过程相似；③染色体数目较少，染色体体积较大；④减数分裂前期具有典型的花束期，没有弥散期，因而不同于蜡蝉。但是由于叶蝉总科的染色体变异范围明显大于角蝉总科，而角蝉总科的核型相对较为保守，从核型上来说角蝉总科是比叶蝉总科较为原始的类群。

Studies on the chromosomes of forty-five leafhopper species (Homoptera:Cicadelloidea) in China

The present paper deals with meiosis and chromosomes in 45 species of Chinese leafhoppers, among which 44 species are cytologically studied for the first time. Chromosome numbers vary from 2n=12 to 26, and sex determination is XO type in all species. Chromosomal histogram of Cicadelloidea shows that chromosome number vary from 2n=8 to 28, the predominant type is 2n=18(16+XO), and other types such as 2n=16, 20 and 22 are also very common. Positive trend on chromosome number evolution was not found, and 2n=22(20+XO) is suggested to be initial karyotype. Unequal exchange between homologous chromosomes induced by translocation is the main mechanism of karyotype evolution. Male meiosis indicates that the relationship between Cicadelloidea and Membracoidea is very close, and they share the following characteristics: ①volume of spermatocytes is bigger than that in Cercopoidea and Cicadoidea; ② chromosome behaviors during meiosis are similar; ③fewer chromosomes but with bigger volume; ④differing from Fulgoroidea, meiosis prophase Ⅰ has typical bouquet stage but without diffuse stage. It is suggested that Membracoidea, are more primitive than Cicadelloidea, since chromosome numbers are much varied in Cicadello Idea but conservative in Membracoidea.