“三叶”宜昌橙体细胞联会现象观察与分析

对＂三叶＂宜昌橙茎尖细胞有丝分裂中期染色体联会现象进行了初步的观察与分析。结果表明：在观察到的154个中期分裂相中,有62个存在染色体联会现象,出现频率为40.3%;共观察到124个联会复合体,其中以2条染色体之间的联会最多,占总数的59.6%,其次分别为3条、4条和5条染色体联会复合体,各占25.8%、12.9%和1.6%;染色体联会一般以端部-端部、端部-中部连接并形成棒形、V形、U形、Y形、T形和O形等多种构型。对宜昌橙体细胞联会研究意义进行了讨论。 Synapsis in metaphase of mitosis in ＇ Sanye ＇ Citrus ichangensis （ 2n = 2x = 18 ） was observed and analyzed. The results showed that chromosome synapsis appeared in 62 cells of all 154 cells, and the ratio of synapsis was about 40. 3%. 124 synaptonemal complexes were observed, in which 59.6%were two-chromosome synapsises followed by three-chromosome, four-chromosome and five-chromosome synapsises with corresponding ratios of 25.8%, 12. 9% and 1.6%. Chromo somes shaped like I, V, U, Y, T and O through top-to-top or top-to-middle synapsis. The research significance of somatic synapsis in Citrus ichangensis was also discussed.