Comparative palynological and wood anatomical studies of Indian Taxus wallichiana Zucc., Cephalotaxus mannii Hook. and Cephalotaxus griffithii Hook.

A comparative study of Taxus wallichiana Zucc., Cephalotaxus mannii Hook. and Cephalotaxus griffithii Hook. of two families Taxaceae and Cephalotaxaceae has been carried out in detail to support the taxonomic existence of two families. The comparative studies have been carried out on the basis of wood anatomy and palynology. The anatomical properties of wood including the tracheids, ray parenchyma, axial parenchyma and number of cross-field pits have been described in detail. The palynological studies include the shape, size and ultrastructure of pollen grains. These studies give a taxonomic support for the recognition of two different genera of families Taxaceae and Cephalotaxaceae which are closely related.     

红豆杉科、三尖杉科和罗汉松科植物叶片结构的比较观察

扫描电镜和光镜下的叶表皮特征以及叶片解剖结构的研究结果,支持在红豆杉科内建立白豆杉属的处理方式;赞同在三尖杉属内建立篦子三尖杉组,叶片解剖结构方面,三尖杉科和红豆杉科的穗花杉属的相似之处颇多。而叶表皮形态特征方面又表现为三尖杉科和罗汉松科更加接近。反映了出了红豆杉科、三尖杉科和罗汉松科之间的密切而又复杂的系统关系。     

从木材解剖特征初拟针叶树分类系统

<正> 针叶树(Conifers)包括银杏纲和松杉纲的树种。根据《中国植物志》第七卷记载,现代裸子植物的种类分属于4纲9目12科71属约800种,我国产4纲8目11科41属236种,栽培1科7属51种。从国产针叶树材的解剖特征观察,银杏纲木材构造简单,仅具管胞、含晶细胞和射线细胞。管胞排列不整齐,射线薄壁细胞垂直壁无节状加厚,四隅无凹痕,轴向薄壁细胞缺,射线仅单例,所以是针叶村最原始的一个纲,应排列在松杉纲之前。     

Tetracentron Wood from the Miocene of Noto Peninsula,Central Japan,with a short revision of homoxylic fossil woods

A vesselless fossil wood was discovered in the Miocene Yanagida Formation in the Noto Peninsula, central Japan. This fossil has distinct growth rings with gradual transition from the early- to the latewood ; tracheids, which are called 'usual traeheids' here, constitute the ground mass of the wood and have typical scalariform bordered pits on radial walls in the earlywood and circular sparse pits on those in the latewood ; rays are 1\2-4 cells wide and heterogeneous with low to high uniseriate wings; axial parenchyma strands are scattered in the latewood. This wood has a peculiar feature; sporadic radial files of broad tracheids whose tangential walls have crowded alternate bordered pits. The radial walls have crowded half-bordered pits to ray cells, but no pits to the usual tracheids. Among all of the extant and extinct angiosperms and gymnosperms, these unusual tracheids occur only in Tetracentron. From these features, we refer the fossil to the extant genus Tetracentron, and name it T. japonoxylum. A revision of homoxylic woods is made for comparision with the present fossil. Tetracentron japonoxylum is the only fossil wood of Tetracentron.     

中国裸子植物木材具缘纹孔构造类型的研究

根据100种中国裸子植物木材(隶属4纲、8目、11科,42属)具缘纹孔构造的研究,提出8种不同具缘纹孔类型:1.苏铁型;2.南洋杉 A 型;3.南洋杉 B 型;4.落羽杉 A 型;5.落羽杉 B 型;6.松木 A 型;7.松木 B 型;8.买麻藤型。A 型是指纹孔室内瘤状层缺乏或罕见,B型则具明显的瘤状层。并对具缘纹孔在系统发育中的变化进行了讨论。     

Modelling the hydrodynamic resistance of bordered pits

Previous studies of the hydrodynamics of plant stems have shown that resistance to flow through bordered pits on the side walls of tracheids makes up a significant proportion of their total resistance, and that this proportion increases with tracheid diameter. This suggests a possible reason why tracheids with a diameter above around 100 microm have failed to evolve. This possibility has been investigated by obtaining an estimate for the resistance of a single pit, and incorporating it into analytical models of tracheid resistance and wood resistivity. The hydrodynamic resistance of the bordered pits of Tsuga canadensis was investigated using large-scale physical models. The importance of individual components of the pit were investigated by comparing the resistance of models with different pore sizes in their pit membrane, and with or without the torus and border. The estimate for the resistance of a real bordered pit was 1.70x10(15) Pa s m(-3). Resistance of pits varied with morphology as might be predicted; the resistance was inversely proportional to the pore size to the power of 0.715; removing the torus reduced resistance by 28%, while removal of the torus and border together reduced it by 72%. It was estimated that in a 'typical tracheid' pit resistance should account for 29% of the total. Incorporating the results into the model for the resistivity of wood showed that resistivity should fall as tracheid diameter increases. However, to minimize resistance wider tracheids would also need to be proportionally much longer. It is suggested that the diameter of tracheids in conifers is limited by upper limits to cell length or cell volume. This limitation is avoided by angiosperms because they can digest away the ends of their cells to produce long, wide vessels composed of many short cells.     

Phylogenetic relationships of conifers inferred from partial 28S rRNA gene sequences

The conifers, which traditionally comprise seven families, are the largest and most diverse group of living gymnosperms. Efforts to systematize this diversity without a cladistic phylogenetic framework have often resulted in the segregation of certain genera and/or families from the conifers. In order to understand better the relationships between the families, we performed cladistic analyses using a new data set obtained from 28S rRNA gene sequences. These analyses strongly support the monophyly of conifers including Taxaceae. Within the conifers, the Pinaceae are the first to diverge, being the sister group of the rest of conifers. A recently discovered Australian genus Wollemia is confirmed to be a natural member of the Araucariaceae. The Taxaceae are nested within the conifer clade, being the most closely related to the Cephalotaxaceae. The Taxodiaceae and Cupressaceae together form a monophyletic group. Sciadopitys should be considered as constituting a separate family. These relationships are consistent with previous cladistic analyses of morphological and molecular (18S rRNA, rbcL) data. Furthermore, the well-supported clade linking the Araucariaceae and Podocarpaceae, which has not been previously reported, suggests that the common ancestor of these families, both having the greatest diversity in the Southern Hemisphere, inhabited Gondwanaland.     

The First Record of Fossil Wood of Winteraceae from the Upper Cretaceous of Antarctica

Fossil wood of the Winteraceae from the Upper Cretaceous sedimentsof James Ross Island, Antarctic Peninsula, is described herefor the first time. The specimen is characterized by the absenceof vessels, rays of two distinct sizes and tracheids with one–threerows of circular bordered pits, mainly on the radial walls,grading to horizontally elongate and scalariform. Despite anatomicalconformity to the family Winteraceae, the fossil wood is notidentical to any one extant genus and therefore has been assignedto the fossil organ genus Winteroxylon Gottwald with which thefossil shows greatest similarity. Copyright 2000 Annals of BotanyCompany Antarctica, Cretaceous, angiosperm, wood, anatomy, Winteraceae, Winteroxylon, fossil, palaeoclimate     

圆籽荷属木材构造的研究

山茶科圆籽荷属(Apterospefma)木材为散孔材至半环孔材,管孔细,射线细,薄壁组织肉眼下不见,密度中偏大,纹理直,结构细。微观构造:在导管相互间纹孔式对列夏导管分子穿孔梯状的横栅24—77条,射线异形Ⅰ型。射线与导管问纹孔为较大不规则形单纹孔,对列,薄壁组织星散.1—2个细胞。     

红豆杉科及相关类群rbcL基因PCR—RFLP分析

运用RFLP方法对红豆杉科及相关类群14种植物叶绿体rbcL基因PCR产物进行限制酶酶切分析,共获29个酶切变异位点。采用PHYLIP软件包对限制位点变异数据进行极大简约法分析得到18个步长为6的最简约树并求得一致树,结果显示：⑴红豆杉科和三尖杉科属单系群;⑵穗花杉属Amentotaxus以置于红豆杉科内为宜,不支持将穗花杉属独立成科的处理方式;⑶白豆杉应为红豆杉科内一个属Pseudotaxus;⑷三尖杉属内篦子三尖杉地位特殊,可设篦子三尖杉组;⑸不赞同将竹柏类从罗汉松属中分离出去成立新科;⑹红豆杉科、三尖杉科和罗汉松科三者间,前两者的关系更为接近。     

部分裸子植物叶片总蛋白分析

采用ＳＤＳ－ ＰＡＧＥ 技术, 分析了红豆杉科（Ｔａｘａｃｅａｅ） 植物南方红豆杉（ Ｔａｘｕｓ ｃｈｉｎｅｎｓｉｓｖａｒ－ ｍａｉｒｅｉ （Ｌｅｍｅｅ ｅｔ Ｌｅｖｌ－） Ｃｈｅｎｇ ｅｔ Ｌ－Ｋ－Ｆｕ） 、穗花杉（ Ａｍｅｎｔｏｔａｘｕｓ ａｒｇｏｔａｅｎｉａ （Ｈａｎｃｅ） Ｐｉｌ ｇｅｒ） 、云南穗花杉（ Ａ－ ｙｕｎｎａｎｅｎｓｉｓ Ｌｉ） 、白豆杉（ Ｐｓｅｕｄｏｔａｘｕｓｃｈｉｅｎｉｉ（Ｃｈｅｎｇ） Ｃｈｅｎｇ） 以及三尖杉科（Ｃｅｐｈａｌｏｔａｘａｃｅａｅ） 、植物三尖杉（ Ｃｅｐｈａｌｏｔａｘｕｓ ｆｏｒｔｕｎｅｉ Ｈｏｏｋ－ｆ－） 、粗榧（ Ｃ－ｓｉｎｅｎｓｉｓ （Ｒｅｈｄ－ｅｔＷｉｌｓ－） Ｌｉ） 、海南粗榧（ Ｃ－ｈａｉｎａｎｅｎｓｉｓ Ｌｉ） 、篦子三尖杉（ Ｃ－ｏｌｉｖｅｒｉ Ｍａｓｔ－） 和罗汉松科（Ｐｏｄｏｃａｒｐａｃｅａｅ） 、植 物罗汉松 （ Ｐｏｄｏｃａｒｐｕｓ ｍａｃｒｏｐｈｙｌｌｕｓ （ Ｔｈｕｎｂ－ ） Ｄ－Ｄｏｎ） 、鸡毛 松（ Ｐ－ｉｍｂｒｉｃａｔｕｓ Ｂｌ－） 、竹柏（ Ｐ－ ｎａｇｉ（Ｔｈｕｎｂ－） Ｚｏｌｌ） 、陆均松（ Ｄａｃｒｙｄｉｕｍ ｐｉｅｒｒｅｉ Ｈｉｃｋｅｌ） 共１２ 种植物的叶片蛋白, 在蛋白质水平上采用     

部分裸子植物茎次生韧皮部和木材的比较解剖

茎次生韧皮部和木材的比较解剖支持红豆杉科、三尖杉科和罗汉松科自然类群、不主张建立穗花杉科和竹柏科     

Myosin,microtubules, and microfilaments: co-operation between cytoskeletal components during cambial cell division and secondary vascular differentiation in trees

The immunolocalisation of unconventional myosin VIII ('myosin') in the cells of the secondary vascular tissues of angiosperm (Populus tremula L. x P. tremuloides Michx. and Aesculus hippocastanum L.) and gymnosperm (Pinus pinea L.) trees is described for the first time and related to other cytoskeletal elements, as well as to callose. Both myosin and callose are located at the cell plate in dividing cambial cells, whereas actin microfilaments are found alongside the cell plate; actin and tubulin are both associated with the phragmoplast. Myosin and callose also localise to the plasmodesmata-rich pit fields in the walls of living cells, which are particularly abundant within the common walls between ray cells and between ray cells and axial parenchyma cells in the phloem and xylem. In those xylem ray cells that contact developing vessel elements and tracheids, myosin, tubulin, actin and callose are localised at the periphery of developing contact and cross-field pits; the respective antibodies also highlight the bordered pits between vessels and between tracheids. The aperture of the bordered pits, whose diameter diminishes as the over-arching border of these pits develops, also houses myosin, actin and tubulin. Myosin, actin and callose are also found together around the sieve pores of sieve elements and sieve cells. We suggest that an acto-myosin contractile system (a 'plant muscle') is present at the cell plate, the sieve pores, the plasmodesmata within the walls of long-lived parenchyma cells, and at the apertures of bordered pits during their development.     

Structural analysis of K<Superscript>+</Superscript> dependence in <Emphasis Type="SmallCaps">l</Emphasis>-asparaginases from <Emphasis Type="Italic">Lotus japonicus</Emphasis>

Wood is composed of various types of cells and each type of cell has different structural and functional properties. However, the temporal and spatial diversities of cell wall components in the cell wall between different cell types are rarely understood. To extend our understanding of distributional diversities of cell wall components among cells, we investigated the immunolabeling of mannans (O-acetyl-galactoglucomannans, GGMs) and xylans (arabino-4-O-methylglucuronoxylans, AGXs) in ray cells and pits. The labeling of GGMs and AGXs was temporally different in ray cells. GGM labeling began to be detected in ray cells at early stages of S₁ formation in tracheids, whereas AGX labeling began to be detected in ray cells at the S₂ formation stage in tracheids. The occurrence of GGM and AGX labeling in ray cells was also temporally different from that of tracheids. AGX labeling began to be detected much later in ray cells than in tracheids. GGM labeling also began to be detected in ray cells either slightly earlier or later than in tracheids. In pits, GGM labeling was detected in bordered and cross-field pit membranes at early stages of pit formation, but not observed in mature pits, indicating that enzymes capable of GGM degradation may be involved in pit membrane formation. In contrast to GGMs, AGXs were not detected in pit membranes during the entire developmental process of bordered and cross-field pits. AGXs showed structural and depositional variations in pit borders depending on the developmental stage of bordered and cross-field pits.     

水青树特殊管胞的分布位置及其形态特征的研究

针对水青树（Tetracentron sinense）中一类特殊管胞进行较为全面的观察研究,判断细胞种类并分析维管组织输导机理及树木进化过程中的细胞演化规律。通过切片和解离技术,借助光学显微镜和电子显微镜对34年生水青树特殊管胞的分布位置和形态特征进行观察。结果表明：(1)特殊管胞在树木水平方向自内向外径向呈串排列,并贯穿年轮界限,多为一列,少数两列,且较为稀见。每个特殊管胞弦向左右两侧或单侧均与木射线细胞相连通。纵向上,特殊管胞单独或数个上下端接相连。(2)特殊管胞主要有以下3种类型：无端壁的纺锤形,有一个倾斜端壁,以及有两个倾斜端壁。特殊管胞的平均长度为286.44μm;横切面为四边形,平均弦向宽度为55.22μm,其平均壁厚为1.53μm。(3)特殊管胞两端封闭,无穿孔。(4)特殊管胞侧面壁上的纹孔数量较多且纹孔膜明显可见,具体表现为：弦面壁上布满特殊管胞之间的具缘纹孔,呈对列、互列偶见梯状排列;径面壁上存在与射线细胞间的具狭缘单纹孔,呈大圆形至椭圆形,每区域多为2～10个纹孔,呈1～4排横列;径面壁上与正常管胞间几无纹孔。水青树特殊管胞分布有一定规律,其长度远小于水青树正常管胞...     

红豆杉科及相关类群rbc L基因PCR-RFLP分析

运用RFLP方法对红豆杉科及相关类群14种植物叶绿体rbcL基因PCR产物进行限制酶酶切分析,共获29个酶切变异位点。采用PHYLIP 软件包对限制位点变异数据进行极大简约法分析得到18个步长为6的最简约树并求得一致树,结果显示：（1）红豆杉科和三尖杉科属单系群;(2) 穗花杉属Amentotaxus以置于红豆杉科内为宜,不支持将穗花杉属独立成科的处理方式;(3)白豆杉应为红豆杉科内一个属Pseudotaxus;(4) 三尖杉属内篦子三尖杉地位特殊,可设篦子三尖杉组;(5) 不赞同将竹柏类从罗汉松属中分离出去成立新科;(6) 红豆杉科、三尖杉科和罗汉松科三者间,前两者的关系更为接近。     

SEM Observation of the Inner Surface Structure of Needle Cuticles in Pinus

Comparative investigation on the inner surfaces of needle cuticle of Pinus was made for 17 species and two varieties under SEM. It is shown that the differences in protrusions and depressions of the internal cuticle surfaces of needles in the genus are not remarkable. However, the features of intercellular flanges are rather distinct and three types can be distinguished. They are: (1) Subgen. Strobus (Sweet) Rehd (except Sect. Parrya) is of the Pinus koraiensis type; (2) Subgen. Pinus is of the P. tabulaeformis type; (3) Sect. Parrya Mayr of Subgen. Strobus (Sweet) Rehd is of the P. bungeana type. The character may provide taxonomy of the genus Pinus with a new piece of evidence. Based on the features mentioned above, together with many others, such as wood anatomy, warts of wood tracheids, bark structure, needle anatomy and cuticle structure as well as karyotypic analysis in Pinus, the author considers that division of Pinus into two subgeuera is natural and that separation of Sect. Parrya Mayr from Subgen. Strobus (Sweet) Rehd. and thesubsequent establishment of the subgenus Parrya of its own are also reasonable.     

白豆杉的叶绿体基因组结构与系统进化分析

以红豆杉科单种属植物白豆杉(Pseudotaxus chienii(W.C.Cheng)W.C.Cheng)为材料,进行叶绿体全基因组测序,并对其基因含量、结构及重复序列进行分析.结果显示:白豆杉叶绿体基因组不包含典型的反向重复区,基因组全长为130427 bp,共编码116个基因,包含83个蛋白编码基因、4个rRNA...     

Comparative Anatomical Observations of Wood Structures of Pinus yunnanensis and P.yunnanensis var. pygmaea

Pinus yunnanensis Franch. and P. yunnanensis Franch. var. pygmaea (Hsüeh) Hsüeh were cultivated at the same area and in the same year. It was found that P. yunnanensis var. pygmaea maintains its dwarfism even growing in a suitable habitat. The wood structures of this dwarf pine exhibit several characters similar to those of the phenotypic dwarf pine, such as that the length of tracheids is shortened; the diameter becomes narrowed; resin canals increase and more or less concentrate in the late wood; the boundary between early wood and late wood is indistinct, etc. However, it is rather difficult to find the twisted tracheids which is commonly seen in the phenotypic dwarf pine.     

The Orientation and Localization of Cortical Microtubules in Differentiating Conifer Tracheids during Cell Expansion

Arrays of cortical microtubules (MTs) on radial walls in differentiatingtracheids of Taxus cuspidata were randomly oriented when primarywalls formed. The orientation of MTs changed progressively fromlongitudinal to transverse as cells expanded. During formationof primary walls, MTs in differentiating tracheids disappearedlocally at sites of future intertracheal bordered pits. In furtherdifferentiated tracheids, circular bands of MTs were observedaround the edges of developing bordered pits. (Received July 17, 1996; Accepted November 11, 1996)