杉科的细胞分类学和系统演化研究

根据杉科的核型资料,本文(1)提出“1B”可能是一个新的高等植物核型类型;(2)讨论了各属的有关分类学问题及相互亲缘关系,它们的进化顺序可能是柳杉属、水松属、落羽杉属、水杉属、巨杉属、红杉属、杉木属(密叶杉属与之近缘)、台湾杉属;(3)支持金松属分立成金松科,它可能比杉科各属原始; (4)红杉(AAAABB)的亲本可能是二个古代种“水杉”和“巨杉”,它们的直接后裔或留下的近缘是水杉和巨杉;(5)杉科存在A和L两条进化路线,前者包括柳杉属、水松属、落羽杉属、台湾杉属;后者包括水杉属、巨杉属、红杉属、杉木属(密叶杉属);(6)提出一个杉科新系统(包括一个新亚科):Ⅰ.柳杉亚科(柳杉属),Ⅱ.落羽杉亚科(水松属、落羽杉属),Ⅲ.红杉亚科(水杉属、巨杉属、红杉属),Ⅳ.杉木亚科(杉木属、密叶杉属),Ⅴ.台湾杉亚科,新亚科(台湾杉属)。本文还对前人的杉科系统作了讨论。     

杉科的细胞分类学和系统演化研究

根据杉科的核型资料,本文(1)提出“1B”可能是一个新的高等植物核型类型;(2)讨论了各属的有关分类学问题及相互亲缘关系,它们的进化顺序可能是柳杉属、水松属、落羽杉属、水杉属、巨杉属、红杉属、杉木属(密叶杉属与之近缘)、台湾杉属;(3)支持金松属分立成金松科,它可能比杉科各属原始;(4)红杉(AAAABB)的亲本可能是二个古代种水杉”和“巨杉”,它们的直接后裔或留下的近缘是水杉和巨杉;(5)杉科存在A和L两条进化路线,前者包括柳杉属、水松属、落羽杉属、台湾杉属,后者包括水杉属、巨杉属、红杉属、杉木属(密叶杉属);(6)提出一个杉科新系统(包括一个新亚科)：I．柳杉亚科(柳杉属),II．落羽杉亚科(水松属、落羽杉属),III．红杉亚科(冰杉属、巨杉属、红杉属),Ⅳ.杉木亚科(杉木属、密叶杉属),V．台湾杉亚科,新亚科(台湾杉属)。本文还对前人的杉科系统作了讨论。     

秃杉的细胞学研究

本文首次报道秃杉的核型为K(2n)=22=16m+6sm, 3号染色体具“长着丝点区 域”。似具比同属的台湾杉(18m+4sm)进化的趋势。它们均为"2B"。从国产杉科植物的 核型类型看,似见"2B"的台湾杉属与"1B"的杉木属和"1A"的水杉属、水松属、柳杉属的亲缘关系依序由近到远并比它们进化。本作者还观察了秃杉的核仁数目和多微核现象。     

杉科植物的系统发育分析

本文以形态学为依据,参考其他学科的研究成果,用分支分类方法并结合表征分类方法探讨了杉科植物的系统演化关系,提出了新的分类系统。在分支分类中,金松科被选作外类群。主要根据外类群比较原则、化石原则和一般的演化规律,确定了性状的祖征和衍征,采用最大同步法、综合分析法、演化极端结合法及最小平行进化法共四种方法进行分支分析,选择最简约的分支图作为本文讨论基础。在表征分类中,选取59个性状,利用距离系数和类平均法,对金松属和杉科各属进行了聚类运算,得出表征图。综合两种分析结果,主要结论如下:(1)属间关系:柳杉属是现存杉科植物中最原始的类群。水松属和落羽杉属关系密切,二者与柳杉属近缘。巨杉属和北美红杉属关系密切,是中级进化水平的类群。水杉属与巨杉属和北美红杉属的亲缘关系相对较近。杉木属、密叶杉属和台湾杉属关系密切,是杉科植物中的高级进化类群,其中又以台湾杉属演化水平最高。(2)系统排列:支持金松科的成立,将杉科分成5族,即柳杉族(仅含柳杉属)、落羽杉族(含水松属、落羽杉属)、北美红杉族(含巨杉属、北美红杉属)、水杉族(仅含水杉属)和杉木族(含杉木属、密叶杉属及台湾杉属)。     

生境的破坏或改变对杉科种属分布的影响

杉科共有10个属16种,其中5个是单种属(水杉属、水松属、巨杉属、北美红杉属、金松属),5个是寡种属(杉木属、台湾杉属、柳杉属、落羽杉属、密叶杉属),两者各占50%。分布于北温带地区,多在东亚和北美洲,仅密叶杉属分布于南半球澳大利亚的塔斯马尼亚。植物与生境是一个互相依存的统一体,而生境的破坏或改变对杉科植物种属分布有严重的影响。在美国加利福尼亚洲现今仅有巨杉和北美红杉两个单种属,这是由于火山爆发留下来,现在仅分布于美国加州部分地区。     

水松的细胞学研究

本文报道了水松的核型公式K(2n)=22=22m,为“1A”类型。染色体相对长度组成为2n=22=2L+4M_2+16M_1。8号染色体具长着丝点区域,这是核型的一个特征。与近缘的国产种柳杉和水杉相比较。三者由原始到进化的顺序可能为(柳杉、水松)、水杉,水松与柳杉最接近,水杉和水松较近缘。本文还计算了水松的染色体体积。     

我国主要杉科花粉扫描电镜特征及化石水松的花粉形态鉴别

本文运用扫描电子显微镜(SEM)和光学显微镜(LM)观察了水松属、柳杉属、杉木属和落羽杉属等代表性物种的花粉形态和细微结构,利用SEM对花粉外壁上附着的微颗粒进行了测量、统计和分析。研究发现,杉木花粉和落羽杉花粉外壁微颗粒及其小刺形态很容易与水松花粉区分开来。然而,水松属与柳杉属花粉形态较为相近,两者主要特点均为近球形,远极面乳头状突起较高,外壁附着的微颗粒具有刺状突起等。本文根据电子显微镜2-4万倍放大观察,分析研究了花粉表面附着的微颗粒大小以及微颗粒之上小刺的数目关系,发现水松与柳杉花粉仍可以通过花粉表面附着的微颗粒特征进行区分。此外,本文还对比了福建天湖山THD-1钻孔晚全新世化石杉科花粉,并认为绝大部分化石杉科花粉与水松花粉形态基本一致。本研究为第四纪化石花粉的属种鉴别提供了新的依据。     

杉科植物的分类学研究

本文对杉科植物的研究历史作了回顾,根据分支分类结果和表征分类结果,提出了一个新的分类系统.以形态学为依据,结合其他学科的研究成果,对杉科的分类作了订正。作者承认杉科植物共9属、12种及3变种,将杉木、厚皮杉木、德昌杉木和米德杉木归并,支持柳杉作为日本柳杉的变种、台湾杉木作为杉木的变种、秃杉和台湾杉归并的观点。     

杉科植物分类学研究

本文对杉科植物的研究历史作了回顾,根据分支分类结果和表征分类结果,提出了一个新的分类系统。以形态学为依据,结合其他学科的研究成果,对杉科的分类作了订正。作者承认杉科植物共９属、１２种及３变种,将杉木、厚皮杉木、德昌杉木和米德杉木归并,支持柳杉作为日本柳杉的变种、台湾杉木作为杉木的变种、秃杉和台湾杉归并的观点。     

杉科的两条演化路线

本文根据核型资料提出杉科可能存在A、L两条演化路线,前者包括由原始到进化的柳杉属、水 松属、落羽杉属、台湾杉属,以平均臂比快速增加、染色体长度比缓慢增加为特征;后者包括依序进化的水杉属、巨杉属、红杉属、杉木属(可能还有密叶杉属),以平均臂比缓慢增加、染色体长度比迅速增加为特点。该结论也得到形态学、解剖学、胚胎学等资料的支持。     

Two Evolutionary Lines of Taxodiaceae

According to the karyotypic data the present author proposes two evolutionary lines, A and L (Fig. 1), in Taxodiaceae (Exclud. Sciadopitys). The former is characterized by a relatively rapid increase of the mean arm ratio but a relatively slow rise of the ratio of the longest chromosome to the shortest one and it is composed of Cryptomeria, Glyptostrobus, Taxodium and Taiwania, which advance from primitive to progressive in the order. The latter is characterized by, on the contrary, a relatively slow increase of mean arm ratio and a relatively rapid rise of the ratio of chromosome size and it comprises Metasequoia, Sequoiadendron, Sequoia and Cunninghamia (probably Athrotaxis also), which advance in the order. The inference is supported by the data from morphology, anatomy, embryology and so on.Key words Taxodiaceae; Karyotype; Evolutionary line     

Phylogenetic Analysis of the Family Taxodiaceae

In the present paper,both cladistic analysis and phenetic analysis were conducted to evaluate the phylogenetic relationships of the Taxodiaceae based on an extensive literature review and study of herbarium． In the cladistic analysis,the Sciadopityaceae was chosen as outgroup．The polarity of characters was determined mainly according to outgroup comparison,fossil evidence and generally accepted viewpoints of morphological evolution．By the result of compatibility analysis,character 2(leaf type),which possessed a much higher coefficient than others whether or not its polarity was altered,was deleted． Finally,a data matrix consisting of all the extant nine genera and 24 characters was analyzed using Maximal Same Step Method,Synthetic Method,Evolutionary Extremal Aggregation Method and Minimal Parallel Evolutionary Method,and four cladograms were generated,of which only the most parsimonious one (Fig．1)was presented for discussion. The cladogram shows that the Taxodiaceae are assorted along five lines of evolution： 1)Metasequoia;2)Sequoiadendron,Sequoia;3)Cryptomeria;4)Glyptostrobus and Taxodium;5)Cunninghamia,Athrotaxis and Taiwania． Ten genera(including Sciadopitys)and 59 characters were used in the phenetic analysis．The phenogram(Fig．2)indicates that Sciadopitys is a very distinct group with remote affinity to the other genera,and the Taxodiaceae are divided into four groups：1)Sequoia,Sequoiadendron;2)Athrotaxis,Cunninghamia and Taiwania;3)Cryptomeria,Glyptostrobus and Taxodium;4)Metasequoia． Based primarily on the result of cladistics,with reference to that of phenetics,the main conclusions were drawn as follows：(1)Generic relationships：Cryptomeria should be considered the most primitive genus in the extant groups of the Taxodiaceae. Glyptostrobus and Taxodium, close to Cryptomeria, are sister taxa and relatively primitive groups. Sequoiadendron and Sequoia are closely related and intermediate advanced. Metasequoia is a more or less isolated taxon, relatively close to Sequoiadendron and Sequoia. Cunninghamia. Athrotaxis and Taiwania might represent a single lineage and form a very advanced group, of which Taiwania may be the most specialized. (2) Systematic treatments: The authors support the viewpoint that Sciadopitys should be treated as an independent family, and suggest that the Taxodiaeae should be divided into five tribes. Systematic arrangements are as follows: Taxodiaceae Warming Trib. 1. Cryptomerieae Vierhapper Gen. 5. Sequoia Endl. Gen. 1. Cryptomeria D. Don Trib. 4. Metasequoieae Pilger et Melchior Trib. 2. Taxodieae Benth. et Hook. Gen. 6. Metasequoia Miki ex Hu et Cheng Gen. 2. Glyptostrobus Endl. Trib. 5. Cunninghamieae Zucc. Gen. 3. Taxodium Rich. Gen. 7. Cunninghamia R. Br. Trib. 3. Sequoieae Wettstein Gen. 8. Athrotaxis D. Don Gen. 4. Sequoiadendron Buchholz Gen. 9. Taiwania Hayata     

The Karyotype Analysis of Arthrotaxis (Taxodiaceae) and Its Systematic Position

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 terminology 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 advanced 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 (Wettstein) 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.     

Phylogenetic relationships in Taxodiaceae and Cupressaceae sensu stricto based on matK gene, chlL gene, trnL-trnF IGS region, and trnL intron sequences

Nucleotide sequences from four chloroplast genes, the matK, chlL, intergenic spacer (IGS) region between trnL and trnF, and an intron of trnL, were determined from all species of Taxodiaceae and five species of Cupressaceae sensu stricto (s.s.). Phylogenetic trees were constructed using the maximum parsimony and the neighbor-joining methods with Cunninghamia as an outgroup. These analyses provided greater resolution of relationships among genera and higher bootstrap supports for clades compared to previous analyses. Results indicate that Taiwania diverged first, and then Athrotaxis diverged from the remaining genera. Metasequoia, Sequoia, and Sequoiadendron form a clade. Taxodium and Glyptostrobus form a clade, which is the sister to Cryptomeria. Cupressaceae s.s. are derived from within Taxodiaceae, being the most closely related to the Cryptomeria/Taxodium/Glyptostrobus clade. These relationships are consistent with previous morphological groupings and the analyses of molecular data. In addition, we found acceleration of evolutionary rates in Cupressaceae s.s. Possible causes for the acceleration are discussed.     

杉科的染色体资料及在系统演化研究中的作用

杉科共由10属(包括金松属)、20种(变种)组成。本文整理了19种(占95％,隶10属)植物的染色体数目和16种(占80％,隶9属)的核型资料,核型的模式图如图1所示。通过对这些细胞学资料的分析,笔者支持2n=20、x=10的金松属从杉科(2n=22、x=11)分立成金松科。根据其他各属间的亲缘关系,本作者认为可以把它们分隶于5个亚科:Ⅰ.柳杉亚科:Cryptomerioideae(Cryptomeria);Ⅱ.落羽杉亚科Taxodioideae(Glyptostroous,Taxodium);Ⅲ.红杉亚科Sequoideae(Metasequoia,Sequoiadendron,Sequoia);Ⅳ.杉木亚科Cunninghamioideae(Cunninghamia,还可能有:Athrotaxis);Ⅴ.台湾杉亚科Taiwainoideae(Taiwania)。这些亚科和属的进化水平依序渐增,它们分别位于进化路线A(亚科Ⅰ、Ⅱ、Ⅴ)和进化路线L(亚科Ⅲ、Ⅳ)上。这些结果是前人的演化系统所没有涉及的,表明了染色体资料在杉科的系统演化研究中起着重要的作用。     

Cytological Investigation of Taiwania flousiana Gaussen (Taxodiaceae)

The present paper deals with the cytological investigation of Taiwania flousiana Gaussen. The somatic chromosomes in root-tip cells of the plant are found to be 2n=22 for the first time, all with median and submedian constrictions. According to the terminology defined by Levan et al.^[11], the karyotype formula is K(2n)=16m+6sm, which belongs to “2B” of Stebbins'^[16,17] karyotypic symmetry and is generally regarded as a relatively primitive one. The species' chromosome complement is 2n=22=4L+6M₂+8M₁+4s according to the standard defined by Kuo et al.^[10] based on relative length. The nucleolus number in resting root-tip cells of T. flousiana is found to be 1-5 (Table 3). The percentage of cells with two nucleoli is 77.6%, and those with five nucleoli, the highest number ever found by me, is only 1.6%. A few cells with many micronuclei are found in this species for the first time (Plate 1, 1). Although T. flousiana and T. cryptomerioider have the same “2B” type of karyotypic symmetry, the differences in the arm ratio and the index of the karyotypic asymmetry (Table 2) show that the karyotype of the former is less symmetrical than that of the latter, so the former may be a little more advanced than the latter. The basic karyotype (2B) of Taiwania is more related to that of Cunninghamia (1B)^[3] than to that (1A) of Metasequoia^[5], Glyptostrobus^[4] and Cryptomeria^[3]. Wang et al.^[1], have reached the similar conclusion from the embryological study.     

益母草的核型研究

<正> 益母草Leonurus japonicus Houtt, (L. heterophyllus Sweet, L. artemisia(Lour,) S. Y. Hu)是唇形科益母单属的一、二年生草本植物,全国各地均产,朝鲜和日本也有分布,生于旷野向阳处,海拔可达3400米。 益母草是著名的重要中药,《神农本草经》和明李时珍的《本草纲目》列为上品,性微寒,味辛苦,具有活血调经、祛瘀生新之功效,为妇科要药,果实名“茺蔚子”,能清肝明目。