山茶属古茶组植物的细胞学研究

KARYOTYPICAL STUDY OF SECT.ARCHECAMELLIA OF GENUS CAMELLIA

对８种山茶属古茶组（Ｓｅｃｔ．ＡｒｃｈｅｃａｍｅｌｌｉａＳｅａｌｙ）植物的核型进行了研究。结果如下：Ｃａｎｍｅｌｌｉａｅｕｐｈｌｅｂｉａ２ｎ＝２ｘ＝３０＝２１ｍ＋９ｓｍ，Ｃ．ｐｉｎｇｇｕｏｅｎｓｉｓ２ｎ＝２ｘ＝３０＝２３ｍ（１ｓａｔ）＋７ｓｍ；Ｃ．ｐｉｎｇｇｕｏｅｎｉｓｖａｒ．ｔｅｒｍｉｎａｌｉｓ２ｎ＝２ｘ＝３０＝２４ｍ＋６ｓｍ；Ｃ．ｆｌａｖｉｄａ２ｎ＝２ｘ＝３０＝２３ｍ＋７ｓｍ；Ｃ．ｐｏｒｖｉｐｅｔａｌａ２ｎ＝２ｘ＝３０＝２１ｍ（１ｓａｔ）＋９ｓｍ；Ｃ．ｔｏｎｋｉｎｅｎｓｉｓ２ｎ＝２ｘ＝３０＝２６ｍ＋３ｓｍ＋１ｓｔ；Ｃ．ｈｕａｎａ２ｎ＝２ｘ＝３０＝２２ｍ＋８ｓｍ；Ｃ．ｆａｓｃｉｃｕｌａｒｉｓ２ｎ＝２ｘ＝３０＝１８ｍ＋１２ｓｍ（ｌｓａｔ）；Ｃ．ｐｕｂｉｐｅｔａｌａ２ｎ＝２ｘ＝３０＝１８ｍ（２ｓａｔ）＋１０ｓｍ（１ｓａｔ）＋２ｓｔ．其中４种１变种的核型为首次报道。总结古茶组植物的所有核型资料，发现具有下列特征：（１）古茶组植物的染色体数目一致，都是２ｎ＝３０，全为二倍体；（２）组内种间核型比较相似，常有２０－２４条ｍ染色体，６－１０条ｓｍ染色体，０－２条ｓｔ染色体，随体常为２个；（３）整个组的核型的不对称性较?

species of yellow Camellia were cytotaxonomically studied in this work,7 of which be-long to Sect. ArchecanJellia.Some of karyotypes are reported for the first time. The results are show as follows:C.euphlebia 2n=2x=30=21m+9sm,C.pingguoensis 2n=2x=30=23m(1sat)+7sm; C.pingguoenis var.terminalis 2n=2x=30=24m+6sm, C.flavida 2n=2x=30=23m+7sm;C.porvipetala 2n=2x=30=21m(1sat)+9sm;C. tonkinensis 2n = 2x = 30= 26m+3sm+1st:C. huana 2n=2x=30 = 22m+8sm:C. fascicularis 2n=2x=30=18m+12sm(1sat);C.pubipetala 2n=2x=30=18m(2sat)+10sm(lsat)+2st. All cytological data of Sect.Archecamellia were collected.Three characters of the karyotypes of Sect.Archecamellia were found according to these data. (1) All species of this section have a common chromosome number 2n=30,and are diploid.(2) The karyotypes of species are very similar. There are 20一24 m一chromosomes.6 10 sm chromosomes.0 2 st一chromosomes and 0一2 satlites in this section. The satlites are usually situated in two pairs of the shortest chromosomes.(3) The asymmetry of karyotypes is relatively low. The karyotypes are almost 2A. The average of arm ratio is only 1. 52 in this section. Based on above results and extemal morphology,the au-thors deduced that gene mutation and recombination play a leading role in the evolution of Sect. Archecamellia,and polyploidy hardly takes any effect.