侧柏亚科三种植物的核型及其细胞分类学研究

STUDIES ON THE KARYOTYPES OF THREE SPECIES AND THE CYTOTAXONOMY OF THUJOIDEAE (DUPRESSACEAE)

分析了北美乔柏（Ｔｈｕｊａｐｌｉｃａｔａ）、北美香柏（Ｔ．ｏｃｃｉｄｅｎｔａｌｉｓ）和西方翠柏（Ｃａｌｏｃｅｄｒｕｓｄｅｃｕｒｒｅｎｓ）的核型，它们的核型公式分别为Ｋ（２ｎ）＝２２＝１６ｍ＝６ｓｍ（２ＳＡＴ），２０ｍ（２ＳＡＴ）＋２ｓｍ和２０ｍ（２ＳＡＴ）＋２ｓｍ。北美乔柏的核型为首次报道。经对侧柏亚科１０个属（２２种）的核型的比较分析，似见南半球５属（Ｃａｌｉｔｒｉｓ，Ａｃｔｉｎｏｓｔｒｏｂｕｓ，Ｌｉｂｏｃｅｄｒｕｓ，Ｍｉｃｒｏｂｉｏｔａ，Ｗｉｄｄｒｉｎｇｔｏｎｉａ）和侧柏属（Ｐｌａｔｙｃｌａｄｕｓ）及Ｔｅｔｒａｃｌｉｎｉｓ最为原始，罗汉柏属（Ｔｈｕｊｏｐｓｉｓ）和崖柏属（Ｔｈｕｊａ）最进化，翠柏属（Ｃａｌｏｃｅｄｒｕｓ）居中。本文还讨论了翠柏属。

The present paper deals with the karyotype analyses of Thuja plicata, T. occidentalis and Calocedrus decurrens. The karyotype formulas of the species are K(2n)=22=16m+6sm(2SAT), 20m(2SAT)+2sm and 20m(2SAT)+2sm respectively. The karyotype of T. plicata is reported for the first time. The comparison among the karyotypes of 10 genera in Thujoideae (Table 2, Fig.2) shows that the genera in the Southern Hemisphere (including Callitris, Actinostrobus, Libocedrus, Microbiota and Widdringtonia) and Tetraclinis and Platycladus in the Northern Hemisphere may be the most primitive, Thujopsis and Thuja the most advanced, and Calocedrus intermediate. The paper also discusses the classificatory positions of Calocedrus, Platycladus andthe southerngenera.