| 密叶杉属的核型分析及其系统位置的探讨 |
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| 引用本文： | 李林初.密叶杉属的核型分析及其系统位置的探讨[J].中国科学院研究生院学报,1992,30(4):331-341. |
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| 作者姓名： | 李林初 |
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| 摘 要： | 本文首次对特产澳大利亚塔斯马尼亚岛的Athrotaxis cupressoides和Athrotaxis selaginoides进行了核型分析，核型公式分别为2n=22=22m(2SAT)和2n=22=20(2SAT)+2sm，均属Stebbins的1B类型，它们的染色体相对长度组成为22=2L+10M2+8Ml+2S和22=2L十10M2+6Ml+4S，后者比前者较为进化。根据密叶杉属和杉科其他各属核型资料的比较分析，它们由原始到进步的顺序可能为：柳杉属、水松属、落羽杉属、水杉属、巨杉属、红杉属，密叶杉属、杉木属和台湾杉属。 密叶属与红杉属、巨杉属和杉木属较为近缘。 这些在以染色体长度比和平均臂比为纵、横坐标的图上得到清楚反映。 根据核型资料，密叶杉属以隶于单型的亚科Arthrotaxoideae较为合适，这也得到形态学、胚胎学、孢粉学和地理学资料的支持。 本文还对前人系统中的密叶杉属位置进行了讨论。
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| 关 键 词： | 密叶杉属 杉科 核型 系统学 |
The Karyotype Analysis of Arthrotaxis (Taxodiaceae) and Its Systematic Position |
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| Li Lin-Chu.The Karyotype Analysis of Arthrotaxis (Taxodiaceae) and Its Systematic Position[J].Journal of the Graduate School of the Chinese Academy of Sciences,1992,30(4):331-341. |
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| Authors: | Li Lin-Chu |
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| Abstract: | The present paper deals for the first time with an analysis of the
karyotypes of Athrotaxis cupressoides Don and A. selaginoides Don endemic to
Tasmania (Australia). Their morphology of somatic chromosomes in seed root-tip
cells, chromosome measurements, and diagrams are shown in Plate 1, Table 1
and Fig. 1 respectively, The karyotypic formulas of the two species are
2n = 22 = 22m (2SAT) and 2n = 22 = 20m(2SAT ) + 2sm according to of terminolo-
gy Lexvan et al (1964). They all belong to IB type of Stebbins’(1971)karyotypic
asymmetry which was reported for the first time in the higher plants by
Li(1987b). Their chromosome complements are 22 = 2L + 10M2+ 8M1+ 2S and 22
=2L+ 10M2+ 6M1+ 4S respectively according to the standard defined by Kuo et
al. (1972) based on relative length. The karyotype of A. selaginoides is more ad-
vanced than that of A. cupressoides.
In the light of karyotypic data, the sequence of the taxo-diaceous genera (excl.
Sciadopitys) from primitive to advanced may be in the following order:
Cryptomeria, Glyptostrobus, Taxodium, Metasequoia, Sequoiadendron, Sequoia,
Athrotaxis, Cunninghamia and Taiwania. The genus Athrotaxis is closely related
to Sequoia (Sequoiadendron) and Cunninghamia The peculiarity of the karyotype
of Athrotaxis deserves the establishment of a new status Arthrotaxoideae (Wettste-
in) L. C. Li This suggestion is also supported by the data from morphology,
embryology, palynology and geography. The family Taxodiaceae is divided into
six subfamilies and nine genera, as shown in the following table:—————————————————————————————————————————————————
1. Cryptomerioideae Hida Cryptomeria D. Don 4. Arthrotaxoideae (Wettstein) L. C. Li
2. Taxodioideae Pilger Glyptostrobus Endl. Taxodim Richard Athrotaxis D. Don
3. Sequoideae Saxton metasequoia Miki ex Hu et 5. Cunninghamioideae Hida Cunninghamia
Cheng Sequoiadebron Buch. Sequoia Endl. R.Brown
6. Taiwanioideae (Hayata)L. C. Li
Taiwanta Hayata—————————————————————————————————————————————————
The systematic positions of Athrotaxis in the systems of other authors are dis-cussed too. |
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| Keywords: | Athrotaxis cupressoides Athrotaxis selaginoides Taxodiaceae Karyotype Systematics |
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