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1.
利用光学显微镜和扫描电子显微镜,观察了新疆委陵菜属5组不同花柱组10种4变种植物叶表皮的微形态特征,测量统计叶表皮毛的类型、表皮细胞的形状及大小、气孔器的分布及类型、气孔的形状、大小、密度及指数、气孔外拱盖形态及其纹饰等指标。结果显示:新疆委陵菜属10种4变种植物叶的下表皮均有气孔器的分布,形状为长椭圆形、椭圆形、宽椭圆形和近圆形;气孔器的类型多为无规则四细胞型、无规则型、围绕型和辐射型;表皮毛的类型为针状毛、带状柔毛和腺毛;表皮细胞的形状分为不规则形和多边形2种类型。研究表明,新疆委陵菜属植物表皮毛特征、叶片表皮细胞的形状、垂周壁式样、气孔器的形状类型、气孔密度指数及外围蜡质纹饰等存在差异,对属以下等级的划分有重要价值,可作为物种分类及鉴别的依据,同时也为本属一些分类群间的系统关系的探讨提供佐证。  相似文献   

2.
利用光学显微镜对金星蕨科(Thelypteridaceae)8属16种植物的叶表皮形态进行了观察和研究,为金星蕨科植物的系统演化及分类提供科学依据。结果表明:(1)16种金星蕨科植物的叶片表皮细胞为不规则型,表皮细胞垂周壁大多呈深波状。(2)气孔为下生型,多呈椭圆形;共观察到6种气孔器类型(极细胞型、腋下细胞型、聚合极细胞型、聚腋下细胞型、不规则型和聚围绕细胞型),每种植物具2~5种不同类型的气孔器。(3)金星蕨科8属植物在表皮细胞大小、垂周壁形状、气孔大小和形状、气孔密度、气孔指数和气孔器类型上存在一定的属间差异。  相似文献   

3.
27种木犀属植物叶表皮微形态特征的研究   总被引:5,自引:1,他引:4  
利用光学显微镜和扫描电子显微镜观察了27种木犀属植物的叶表皮,测量并统计了气孔器类型、气孔大小、气孔密度、气孔指数及腺点密度等指标,以明确各种的叶表皮细胞形状及垂周壁式样、表皮角质膜、蜡质纹饰及气孔外拱盖的具体特征。结果显示:木犀属植物叶下表皮有气孔器,形状为圆形、椭圆形;气孔器类型多为不规则型,只有总状桂花和狭叶木犀为环列型;气孔器外围角质层有放射状、条状、环状、颗粒状等多种类型;叶表皮细胞形状有无规则形和多边形2种;下表皮腺点的数目远远大于上表皮。研究表明,木犀属植物气孔器和叶表皮细胞特征在种之间差异比较明显,可以作为种间鉴定的重要依据,具有重要的分类学意义。  相似文献   

4.
为解决荚蒾属植物分类学问题并探究叶片解剖结构在分类学中的价值,该研究利用光学显微镜和扫描电子显微镜对21种中国荚蒾属植物的叶表皮细胞、气孔大小、气孔器类型和角质层纹饰等叶表皮微形态特征进行了观察和比较,为荚蒾属种间分类关系提供证据。结果显示,叶表皮细胞有无规则形和多边形2种,垂周壁式样有平直、浅波状、波状与深波状4种式样,其中下表皮细胞形状均为不规则形,且垂周壁式样较上表皮更稳定。气孔均分布在下表皮,形状为近圆形、椭圆形2种;气孔器类型包括不等型、平列型和无规则型3种;气孔器外拱盖内缘有近平滑、浅波状、波状3种;气孔器外围角质层纹饰有脊状隆起、条状隆起2种。研究表明,荚蒾属植物叶表皮细胞和气孔器特征在种间差异明显,可作为种间鉴定及分类的重要依据,具有重要的分类学意义。  相似文献   

5.
6种松科植物叶表皮的扫描电镜观察   总被引:17,自引:5,他引:12  
邵邻相  张凤娟 《植物研究》2005,25(3):281-285
应用扫描电子显微镜,观察了松科(Pinaceae)3个属6种植物叶表皮特征.金钱松气孔带位下表面,气孔区与非气孔区表皮细胞形态差异很大,气孔细缝状;雪松针叶四面都具气孔线,气孔下陷,孔口光滑,针叶表面具较厚的角质层,表皮细胞形状观察不清;五针松针叶仅两腹面有气孔线,气孔有隆起的圆环围绕,表面角质层呈条纹状排列,形成一种沟槽;黑松、湿地松、马尾松针叶腹背面都有气孔线,气孔呈蜂窝状排列成行,气孔下陷,孔口角质化强烈.结果表明松科3个属植物叶表皮的形态结构及气孔器差异显著,一定程度上证实了3属是自然的分类群.  相似文献   

6.
利用光学显微镜和扫描电子显微镜,观察了新疆委陵菜属(Potentilla L.)锥状花柱组(Sect.Conostylae(Wolf)Yü et Li)15种委陵菜植物叶表皮的微形态特征。对其叶表皮毛的类型、表皮细胞的形状及大小、气孔器的分布、气孔器类型、气孔形状、气孔大小、气孔密度、气孔指数、气孔外拱盖形态及其纹饰等指标进行分析:有几种植物叶的上表皮无气孔,而下表皮均有气孔器的分布,形状为长椭圆形、椭圆形、宽椭圆形和近圆形;气孔器的类型多为短平列四细胞型、无规则四细胞型、无规则型、围绕型和辐射型;表皮毛的类型为针状毛、带状柔毛和腺毛;表皮细胞分为不规则形和多边形;表皮毛特征、叶片表皮细胞的形状、垂周壁式样、气孔器的形状类型、气孔密度指数及蜡质纹饰等存在差异,可作为亚属间及种间分类的依据。  相似文献   

7.
采用徒手切片法对新疆木灵藓属(Orthotrichum Hedw.)18种植物孢蒴上的气孔、茎和叶进行了比较解剖学观察。研究结果表明,木灵藓属植物茎横切结构形状稳定,由表皮和皮层组成,无中轴细胞分化;除半裸木灵藓(Orthotrichum hallii Sull.et Lesq.)外,其它种叶上部均为单层细胞;叶中部边缘外卷,叶细胞具有高度不同的分叉疣或单疣。在确定气孔显、隐型的基础上,茎和叶横切面的颜色、茎表皮和皮层细胞组成及细胞壁加厚程度、叶细胞疣的高度、叶中肋横切面的形状、中肋的宽度、细胞组成以及芽孢形态等特征可作为该属种间分类的依据。还根据18种木灵藓属植物孢蒴上的气孔显、隐型,及茎、叶的比较解剖学特征,编制了新疆木灵藓属植物的分种检索表。  相似文献   

8.
利用光学显微镜和扫描电子显微镜对中国卫矛属(Euonymus L.)24种以及沟瓣属(Glyptopetalum Thw.)3种植物的叶表皮微形态特征进行了观察研究,测量并统计了气孔器长宽比、密度和气孔指数。结果显示,两属植物叶表皮微形态特征基本一致:叶上、下表皮细胞形状多为多边形,垂周壁平直-弓形;气孔器通常仅分布在叶下表皮;均具有无规则型气孔器,部分种还具环列型气孔器。扫描电镜下角质膜纹饰、表皮细胞界限及气孔特征在一些种间存在差异,可以作为区分部分近缘种类的参考依据。  相似文献   

9.
采用徒手切片法对新疆木灵藓属(Orthotrichum Hedw.)18种植物孢蒴上的气孔、茎和叶进行了比较解剖学观察。研究结果表明,木灵藓属植物茎横切结构形状稳定,由表皮和皮层组成,无中轴细胞分化;除半裸木灵藓(Orthotrichum hallii Sull.et Lesq.)外,其它种叶上部均为单层细胞;叶中部边缘外卷,叶细胞具有高度不同的分叉疣或单疣。在确定气孔显、隐型的基础上,茎和叶横切面的颜色、茎表皮和皮层细胞组成及细胞壁加厚程度、叶细胞疣的高度、叶中肋横切面的形状、中肋的宽度、细胞组成以及芽孢形态等特征可作为该属种间分类的依据。还根据18种木灵藓属植物孢蒴上的气孔显、隐型,及茎、叶的比较解剖学特征,编制了新疆木灵藓属植物的分种检索表。  相似文献   

10.
石蒜属植物叶微形态特征研究   总被引:8,自引:2,他引:6  
借助显微和扫描电镜技术对石蒜属植物叶表皮微形态特征进行了研究。利用光学显微镜和扫描电子显微镜观察了石蒜属植物的叶表皮,统计并测量了气孔类型、气孔大小、气孔密度及气孔指数等,描述了气孔及气孔外拱盖的有关特征。结果表明:石蒜属植物叶表皮气孔器为无规则型,近轴面表皮细胞形状、气孔器类型、垂周壁式样、气孔大小及气孔外拱盖内缘种间无差异或极小,表明石蒜属植物为一自然分类群。而远轴面表皮细胞形状、气孔密度、气孔指数、气孔是否下陷、气孔外拱盖是否有蜡质纹饰等种间差异较大。根据远轴面叶表皮细胞形状及叶气孔特征,研究表明:换锦花、长筒石蒜和安徽石蒜,夏水仙、乳白石蒜与红蓝石蒜,石蒜与中国石蒜具有较近的亲缘关系。因此,叶微形态特征对探讨石蒜属植物种间亲缘关系具有一定的意义。  相似文献   

11.
Abstract. Phylogenetic relationships amongst Megastigmus species (Chalcidoidea: Torymidae) associated with conifer seeds were inferred from DNA sequence data. Twenty‐nine species of seed chalcids were analysed using two different genes, cytochrome b (mitochondrial DNA) and the D2 domain of the 28S ribosomal DNA. Maximum‐parsimony and maximum‐likelihood analyses showed that taxa formed two monophyletic groups, one clade comprising all species associated with Cupressaceae and Taxodiaceae hosts with the exception of Chamaecyparis, and the other clade composed of species associated with Pinaceae. Species infesting Cupressaceae and Taxodiaceae seemed to be specialized to particular host genera or even to be species specific, which was consistent with a taxonomic radiation following initial host adaptation. By contrast, Megastigmus species associated with Pinaceae appeared capable of shifting onto different congeneric species or even onto a new host genus, with their evolution apparently less constrained by plant association. We hypothesized that the Megastigmus group associated with Pinaceae may have a much higher invasive potential than that related to Cupressaceae. The study also confirmed the presence of invasive Nearctic species in the Palaearctic, and demonstrated the existence of a cryptic species complex.  相似文献   

12.
Question Are the patterns of alien conifer (Pinaceae, Cupressaceae) invasions different between continents, and how is invasion success influenced by commercial forestry practices? Location Temperate and subtropical countries and regions (n = 60) from five continents spanning both hemispheres. Methods We used generalized linear mixed models to test how continent identity, region area and use in commercial forestry affect probabilities of Pinaceae and Cupressaceae species to escape following introduction and cumulative logit regression models to assess how these predictors affect the likelihood that a species becomes naturalized or invasive. Results Sixty Pinaceae of a global total of 232 and 26 Cupressaceae of a total of 142 species have escaped from cultivation across the study regions examined. Average numbers of both alien Pinaceae and Cupressaceae species per region were highest in Oceania, followed by Africa. Moreover, the probability of alien Cupressaceae and Pinaceae becoming naturalized or invasive was particularly high in these two continents. For both families, species used in commercial forestry have a significantly higher probability of escape than those which are only introduced for ornamental or other purposes. In the case of Pinaceae, forestry species also become naturalized or invasive more frequently than non‐forestry species, while no such effect was detectable for Cupressaceae. Conclusions We found that non‐native conifers are more likely to escape from cultivation, naturalize and turn into invasive weeds on the continents of the Southern Hemisphere. In addition to this biogeographic signal, introduction effort strongly determines the behaviour of introduced Pinaceae, and less so, Cupressaceae. A clear conflict exists between the economic benefits of conifer forestry and the risks to the environment from invasions. Future expansion of commercial forestry should address spatial planning to ecosystems vulnerable to invasion and adopt comprehensive risk assessment procedures.  相似文献   

13.
 Fossil vegetative and reproductive structures from deposits of the Raritan Formation in New Jersey (Turonian, Upper Cretaceous, ∼90 MYBP) include ferns, gymnosperms, and angiosperms. Gymnosperms collected from this formation have been known since the beginning of the 20th century. Fossil leaves, wood and seed cones have been are identified as belonging to the Cupressaceae, Pinaceae, and Taxodiaceae. In the present contribution, we describe a series of fossil dwarf shoots, leaves and a pollen cone belonging to the family Pinaceae. Fossils are charcoalified with preserved three-dimensional structure and excellent cellular detail. The dwarf shoots are assigned to a new species Prepinus crossmanensis sp. nov. and to the previously described Pinus quinquefolia Jeffrey. The new species Prepinus crossmanensis differs in size, shape, presence of hypodermis, sclerenchyma and stomata in the cataphylls, and number and shape of needle leaves from previously known species. Also, isolated leaves were found that were assigned to the new species, Prepinus raritanensis sp. nov. The new species is differentiated by the size and shape of stomata, the presence of number of layers of the hypodermis; and the cell-shape and number of layers of the mesophyll and transfusion tissue. A previously undescribed male cone, Amboystrobus cretacicum gen. and sp. nov., has an axis with spirally attached microsporophylls, each bearing two abaxial ovoid microsporangia. The pollen grains are monosulcate and bisaccate (eusaccate), with an elliptical corpus, granulate exine sculpture, and honeycomb-like wall structure. Received March 21, 2000 Accepted November 13, 2000  相似文献   

14.
蜡梅科植物的叶表皮特征及其在分类上的意义   总被引:10,自引:1,他引:9       下载免费PDF全文
用扫描电镜和光学显微镜观察了蜡梅科3属5种植物成熟叶片远轴面的表皮特征,认为这些表皮细胞特征和气孔器特征在分类上有比较重要的意义。蜡梅属、夏蜡梅属和美国蜡梅属植物的叶表皮毛均为单细胞毛、非腺毛,上、下表皮细胞均为多边形,垂周壁呈深波状,气孔器均为平列型.这三个属的亲缘关系密切,应该归属于同一个大类群-蜡梅科。这为蜡梅属、夏蜡梅属、美国蜡梅属的分类提供了有用的性状特征。这三个属气孔器的演化趋势为:气孔器在保卫细胞的两极无"T"型加厚到有"T"型加厚,气孔器由单层外拱盖到双层外拱盖.  相似文献   

15.
The fatty acid composition of photosynthetic tissues from 137 species of gymnosperms belonging to 14 families was determined by gas chromatography. Statistical analysis clearly discriminated four groups. Ginkgoaceae, Cycadaceae, Stangeriaceae, Zamiaceae, Sciadopityaceae, Podocarpaceae, Cephalotaxaceae, Taxaceae, Ephedraceae and Welwitschiaceae are in the first group, while Cupressaceae and Araucariaceae are mainly in the second one. The third and the fourth groups composed of Pinaceae species are characterized by the genera Larix, and Abies and Cedrus, respectively. Principal component and discriminant analyses and divisive hierarchical clustering analysis of the 43 Pinaceae species were also performed. A clear-cut separation of the genera Abies, Larix, and Cedrus from the other Pinaceae was evidenced. In addition, a mass analysis of the two main chloroplastic lipids from 14 gymnosperms was performed. The results point to a great originality in gymnosperms since in several species and contrary to the angiosperms, the amount of digalactosyldiacylglycerol exceeds that of monogalactosyldiacylglycerol.  相似文献   

16.
This study reports the value of leaf cuticle characteristics in the identification and classification of Iberian Mediterranean species of the genus Pinus (P. nigra subsp. salzmannii, P. pinaster, P. pinea and P. halepensis), with the aim of using these characters to identify isolated cuticles and stomata in palynology slides. Preparations were made of the cuticles of pine needles belonging to one natural Iberian population of each of the above species. A number of epidermal morphological characteristics were then recorded with the aim of distinguishing these species from one another. The structure of the stomatal complex (the shape and arrangement of the subsidiary cells) was different in each species. The aperture of the epistomatal chamber was significantly smaller in P. pinea than in the other species examined, and the variables recorded for the thickening of the guard cells provided relationships that clearly distinguished all four taxa. The width and length of the stomata and the upper woody lamellae, the central distance between the external limits of the medial lamellae borders and the length of the stem were the most useful variables in this respect. The present results contribute to the ongoing discussion regarding the taxonomic classification of the members of Pinus, and provide valuable clues for the identification of Iberian Mediterranean pine species from small pine needle fragments or isolated stomata. After validation of the present results for multiple populations, these results could also be used to help identify fossil leaf macroremains and the scattered/isolated stomata commonly observed in palaeopalynological samples. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 436–448.  相似文献   

17.
 The fatty acid compositions of seed oils from 34 conifer species, mainly Pinaceae and secondarily Cupressaceae, have been determined by gas-liquid chromatography of the methyl esters. As noted in earlier studies, these oils were characterized by the presence of several Δ5-olefinic acids, i.e., 5,9-18:2, 5,9,12-18:3, 5,9,12,15-18:4, 5,11-20:2, 5,11,14-20:3, and 5,11,14,17-20:4 acids, in addition to the more common saturated, oleic, linoleic and α-linolenic acids. Based on these fatty acid compositions, and on those established in earlier systematic studies (totalling 82 species), we established a chemotaxonomic grouping of the main conifer families, i.e., of the Pinaceae, Taxodiaceae, Cupressaceae, and Taxaceae. This was achieved using multivariate analyses (principal component analysis and discriminant analysis). The fatty acids that discriminate best in this classification are the 5,11,14,17-20:4, 9,12,15-18:3 and 5,9,12-18:3 acids. Moreover, it was possible to differentiate between several genera of the Pinaceae: Pinus (including Tsuga and Pseudotsuga), Abies, Cedrus, and Picea plus Larix, represented quite distinct groups. Other fatty acids such as oleic, linoleic, and 5,9-18:2 acids were also important for this purpose. The fatty acid compositions, and particularly the Δ5-olefinic acid contents of conifer seed oils, may thus be applied to the chemosystematic distinction among conifer families as well as genera of the Pinaceae. Received: 3 January 1997 / Accepted: 17 April 1997  相似文献   

18.
The distribution and hosts of the exotic cedar-boring beetle, Callidiellum rufipenne (Motschulsky) (Coleoptera: Cerambycidae), were determined in five northeastern U.S. states by capturing adults on cedar trap logs and by rearing adults from various conifers. This beetle was detected in the coastal states of Massachusetts, Rhode Island, Connecticut, New York, and New Jersey. In these states, adults emerged from the live or dead wood of four genera and eight species of Cupressaceae; species of Pinaceae were not hosts. Through its entire range, C. rufipenne is reported to infest at least 14 species of Cupressaceae, four species of Pinaceae, and one species of Taxaceae; but, records of Pinaceae and possibly Taxaceae are suspect. Based on the number of adults that emerged from coniferous poles in a five-way choice test in the field, the infestation level was significantly greater in Chamaecyparis thyoides (L.) Britton, Sterns, and Poggenburg and Juniperus virginiana L. than in Pinus rigida Miller, Pinus strobus L., and Tsuga canadensis (L.) Carribre (last three species uninfested). In a second test of host preference in the wild, beetles infested four cupressaceous species, but not Abies balsamea (L.) Miller, Picea rubens Sargent, Pinus rigida, P. strobus, and Ts. canadensis in the Pinaceae. Infestation level was highest in Ch. thyoides, followed in decreasing order by Juniperus communis L., Thuja occidentalis L., and J. virginiana. In a comparison of live and dead J. virginiana, beetles developed to adults only in dead trees (36 beetles per tree). When trunk sections of Th. occidentalis with and without bark were offered to females in cages, beetles of the next generation emerged exclusively from wood with bark. In the Northeast, only species of Cupressaceae apparently are suitable hosts for C. rufipenne. Infestation of these species may be prevented or reduced by proper care of live plants and by debarking trees after harvesting.  相似文献   

19.
Parasite-host cospeciation has received much attention as an important mechanism in the diversification of phytophagous insects. However, studies have shown that for certain taxa, it is not host fidelity but host-switching that plays the critical role in speciation. Cinara are aphids (Insecta: Hemiptera: Aphididae: Lachninae) that feed exclusively on the woody parts of conifers of the Cupressaceae and Pinaceae. They are unusual aphids because most Pinaceae play host to several species of Cinara. The aphids show relatively strong host fidelity, and as a consequence historically have been treated based on the taxonomy of their hosts. The historical paradigm of aphid evolution implies that Cinara species have radiated to different parts of the same host species and/or speciated with their host. Using mitochondrial cytochrome oxidase 1 and nuclear elongation factor 1-alpha DNA sequences, we performed molecular phylogenetic analysis of Cinara species, concentrating on those associated with pinyon pines in the southwestern USA. We determined that switching hosts has played a key role in the speciation of the genus, reflected in the polyphyly of pinyon-feeding Cinara. Furthermore, species sharing a common feeding site on different hosts were more closely related to each other than to those sharing the same host but at different feeding sites, suggesting that feeding site fidelity plays a more important role in speciation than does host fidelity in general. This study also elucidated the primary taxonomy of various species: it suggested that Cinara rustica Hottes is a junior synonym of C. edulis (Wilson) and that C. wahtolca Hottes represents two species on the two different pinyon pine species, Pinus edulis Englem. and P. monophylla Torr. & Frem.  相似文献   

20.
Comparative anatomy of resin ducts of the Pinaceae   总被引:5,自引:0,他引:5  
 Resin ducts are common in the Pinaceae. The comparative anatomy of stems and leaves of 50 species and two varieties from ten genera has been investigated. The structure and distribution of resin ducts differ among genera. Resin ducts occur in foliage leaves of ten genera of Pinaceae. Cortical resin ducts are absent in the stems of Pseudolarix and Larix. Resin ducts only occur in the secondary xylem of stems of Pinus, Picea, Cathaya, Larix, Pseudotsuga and some Keteleeria species. All of the epithelial and sheath cells are alive and thin-walled in the resin ducts of stem cortex and mesophyll. Except for Pinus the epithelial cells of resin ducts in the secondary xylem of stems have thick, lignified walls. Comparative study shows there are obvious differences in the resin ducts of different genera; apparent differences do not exist, however, in the resin ducts of different species of the same genus. According to the structure and distribution of the resin ducts in ten genera of Pinaceae, a synoptical arrangement of the genera is given and generic relationships of the Pinaceae are discussed. Received: 12 September 1995 / Accepted: 14 March 1996  相似文献   

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