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1.
新疆10种沙生植物旱生结构的解剖学研究   总被引:17,自引:1,他引:16  
新疆10种沙生植物的形态解剖研究表明,它们为适应沙生环境形态结构发生变化。叶器官的形态呈三种类型:叶片退化成膜质或鳞片状,而由同化枝执行光合功能;叶片上下都具栅栏组织,表皮角质膜厚,表皮毛发达,气孔下陷,输导组织和机械组织都发达;叶片肉质化,叶肉组织不分化,贮水组织发达而输导组织不发达。轴器官中厚壁组织发达,围绕维管组织,维管组织内部也有发达的厚壁组织。根中普遍具有周皮,一些植物存在异常的维管组织,部分植物还具有粘液细胞或结晶。沙生植物形成各种旱生结构,以不同的方式适应沙生环境。  相似文献   

2.
运用石蜡切片方法,观察白花前胡营养器官的显微结构及其分泌道的分布特征,以明确营养器官内分泌结构的分布规律,为揭示白花前胡次生代谢产物的积累提供解剖学依据。结果表明,(1)白花前胡成长根从外到内由周皮、中柱鞘薄壁组织和次生维管组织组成,而且中柱鞘薄壁组织不同于一般双子叶植物根的结构;茎从外到内由表皮、皮层和维管柱组成;叶为异面叶结构。(2)白花前胡根、茎及叶中均有分泌道存在,分泌道在根中分布于中柱鞘薄壁组织和次生韧皮部中,茎中分布于皮层和髓中,叶中分布于维管束上下两侧的薄壁组织中。  相似文献   

3.
贺兰山不同生境旱生灌木的解剖学研究   总被引:9,自引:1,他引:8  
贺兰山荒漠地带三种不同基质生境的20种旱生灌木的营养器官的比较解剖学研究表明:其共同特点是叶片的表面积/体积的比值小,叶表具厚的角质层、表皮毛,气孔下陷、并具孔下室,叶向中栅栏组织发达;轴器官中木栓层细胞层数多,皮层较厚,机械组织发达,木薄壁组织及髓部细胞的细胞壁术化加厚,根内都具周皮、木质部的导管分子大小不一、频率较高。此外,根、茎、叶中普遍存在粘液细胞和草酸钙结晶,部分植物的根和茎内有异常维管组织。这些结构特征都与早生环境相关,而不同基质生境中生长的植物尚存在一定差异。  相似文献   

4.
黄芩的结构与黄芩苷含量的关系   总被引:1,自引:0,他引:1       下载免费PDF全文
应用解剖学、组织化学定位和植物化学技术,研究了一、二年生黄芩(Scutellaria baicalensis Georgi)营养器官的结构特征与黄芩苷积累的关系。结果表明:黄芩各营养器官的结构类似于一般草本双子叶植物,黄芩苷主要分布在各器官的薄壁组织细胞内,其中以维管组织的薄壁细胞为多。器官间含量的不同表现为根〉叶〉茎,这与其结构特征相对应,根中维管组织所占比例最大,其中薄壁组织细胞又占主要部分,故根中黄芩苷含量最高。说明根部是黄芩苷的主要贮存部位,符合黄芩以根入药的传统。不同生长期黄芩苷含量测定结果表明,两年生营养生长前期春季根内含量最高,所以春季采挖为好。  相似文献   

5.
采用石蜡制片法对川西高原区4种高山海棠的根、茎解剖结构进行观测分析,明确根茎结构特征与抗旱性的关系,揭示高山海棠的抗旱适应策略。结果表明:(1)4种海棠植物根茎的解剖构造基本相似,根由周皮组织和维管组织构成,茎由周皮组织、皮层薄壁组织、维管组织和髓组成。(2)根茎中均发现特化结构:根系中木射线细胞增宽至6~8列,有利于增强植物根系的水分横向运输;茎中的栓内层厚壁细胞、环髓带中的厚壁细胞以及导管周围的"假薄壁细胞"均是增强水分输导和机械支持的特化结构特征。(3)4种高山海棠植物在响应干旱逆境时采取的策略有所不同,其中,变叶海棠(Malus toringoides)主要通过根茎中发达的输导组织响应干旱逆境,花叶海棠(M.transitoria)根中强壮的韧皮部和茎中发达的髓结构使之能很好地适应干旱环境,山荆子(M.baccata)通过根中孔径较大的导管和茎中强大的韧皮部来响应干旱逆境,湖北海棠(M.hupehensis)根系中发达的栓内层、韧皮部结构和茎中宽广的髓结构使得干旱适应能力增强。  相似文献   

6.
狭叶柴胡各器官结构与其分泌道的分布规律   总被引:1,自引:0,他引:1  
采用石蜡切片法对狭叶柴胡全株不同器官的结构及各器官中分泌道的分布特征进行了解剖学观察研究.结果表明:(1)狭叶柴胡的主根从外向内由周皮、中柱鞘薄壁细胞环和次生维管组织组成,其中柱鞘薄壁细胞环是不同于一般双子叶植物根的一种结构;茎从外到内由表皮、皮层和维管柱组成;叶为等面叶,其上、下表皮内都具栅栏组织;花主要由花瓣、雄蕊...  相似文献   

7.
美登木根的显微结构及其内生真菌的分布   总被引:5,自引:0,他引:5  
本文采用石蜡永久制片和光学显微摄像的方法对美登木(Maytenus confertiflorus)根的显微结构及其内生真菌的分布进行了研究.结果表明,美登木根的次生结构由周皮和维管组织构成;周皮由木栓层、木栓形成层和栓内层组成,其中木栓层由5~6列长形细胞组成;维管组织中次生韧皮部所占根径的比例达46%,其薄壁细胞中内含物较丰富,次生木质部中分布有导管和木射线及少量木薄壁组织;在美登木木栓层和次生韧皮部中分布有菌丝片段、膨大的菌丝、菌丝团及分生孢子;内生真菌只在一定区域的皮层和次生韧皮部细胞中分布.  相似文献   

8.
应用植物解剖学、组织化学和植物化学方法,对光果甘草各营养器官的结构、总黄酮的组织化学定位和含量差异进行了研究.结果显示:(1)光果甘草叶为异面叶,由表皮、叶肉和叶脉组成.叶表皮具腺毛,叶肉中具胶囊细胞,主脉发达;茎由表皮(周皮)、皮层、维管柱组成,其髓中具有粘液细胞;根由周皮、次生维管组织组成,周皮具厚木栓层,次生维管组织中次生木质部和纤维发达.(2)黄酮类物质在叶中分布在表皮、腺毛、胶囊细胞、厚角组织和韧皮部和木质部中的薄壁细胞中;茎中分布在周皮、韧皮部和粘液细胞中;在根中则分布在周皮中.(3)不同营养器官中黄酮类物质含量存在差异:叶>根茎>主根>茎.(4)温度的下降促使黄酮类物质从地上合成器官向地下储藏器官的转运.建议每年可在果熟期和枯萎期之间采挖药材,地上部分收割也作药用,综合利用光果甘草资源.  相似文献   

9.
应用植物解剖学、组织化学及植物化学方法对白鲜营养器官根、茎、叶的结构及其生物碱的积累进行了研究。结果显示:(1)白鲜根的次生结构以及茎和叶的结构类似一般双子叶植物;白鲜多年生根主要由周皮、次生韧皮部、维管形成层以及次生木质部组成,根次生韧皮部中可见大量的淀粉、草酸钙簇晶、韧皮纤维以及油细胞;茎由表皮、皮层、维管组织和髓组成;叶由表皮、栅栏组织、海绵组织和叶脉组成;在茎和叶初生韧皮部的位置均分布有韧皮纤维,在叶表皮上分布有头状腺毛和非腺毛;在茎和叶紧贴表皮处分布有分泌囊。(2)组织化学分析结果显示:在白鲜多年生根中,生物碱类物质主要分布在周皮、次生韧皮部、维管形成层和木薄壁细胞中;在茎中,生物碱主要分布在表皮、皮层、韧皮部、木薄壁细胞及髓周围薄壁细胞中;在叶中,生物碱主要分布在表皮细胞、叶肉组织和维管组织的薄壁细胞;此外在分泌囊和头状腺毛中亦含有生物碱类物质。(3)植物化学结果显示,秦岭产白鲜根皮/白鲜皮、根木质部、茎和叶中白鲜碱含量分别为0.041%、0.012%、0.004%和0.002%,其中木质部中白鲜碱含量和其他部分地区白鲜皮中白鲜碱含量类似。研究表明,在秦岭产白鲜营养器官中,除根皮/白鲜皮外,在根木质部亦含有大量的白鲜碱,且在茎和叶中亦含有一定的白鲜碱,具有潜在的开发利用价值。  相似文献   

10.
应用植物解剖学、组织化学定位和高效液相色谱法,研究了卵叶远志各营养器官的结构、远志皂苷积累分布状态及含量变化。结果表明.卵叶远志的根包括周皮和次生维管组织两部分.周皮发达,次生韧皮部较厚,韧皮薄壁细胞为其主要成分。次生木质部中导管和纤维发达,导管分布密度较大。茎包括表皮、皮层、维管柱三部分,在皮层与韧皮部之间具有一圈排列紧密的厚壁细胞.推测这圈厚壁细胞具有质外体屏障作用.可保护茎组织免受干旱的伤害。叶为异面叶。根茎的结构表现为旱生特点。组织化学显示远志皂苷在根中分布在次生韧皮部和栓内层:在茎中分布在表皮、皮层和次生韧皮部细胞中:在叶中则分布在叶肉组织和表皮中。根的次生韧皮部为皂苷积累储存的主要场所。高效液相测定结果显示营养器官中都有远志皂苷元的积累.根中的含量高.茎叶中含量较低.说明卵叶远志地上部分也有药用价值。根据不同发育时期根和茎叶中皂苷元的动态变化趋势.建议在5月份(花果期)进行卵叶远志的采收。  相似文献   

11.
云南秋海棠属植物叶片横切面比较解剖研究   总被引:2,自引:1,他引:1  
报道30种主产于云南的秋海棠属植物叶片的横切面解剖构造特征。采用常规石蜡切片法切片观察,结果表明:云南秋海棠属植物叶片薄、横切面均为异面叶、呈典型的阴叶结构,叶肉组织虽有栅栏组织和海绵组织的分化,但栅栏组织不发达,占叶肉组织的比例较小。表皮多为单表皮,极稀复表皮,表皮毛均由多细胞组成。气孔集中于下表皮,孔下室或下陷气孔特大、通气组织极发达;角质层形状多样,呈均匀增厚、瘤状和片状突起;叶绿体椭球形、数多、个体大,主要分布于叶肉组织,集中于栅栏组织。解剖构造特征在各分类组内呈现不完全一致性,而在相同茎的形态类型中有些较一致的特征,在不同种间解剖特征各有差别;根状茎和直立茎类型种类的横切面组织结构表现为表皮细胞壁外的角质层薄、栅栏组织与叶肉组织厚度比例较小等弱光照、湿生等适应性较弱的特征。球茎类型的种类表现为角质层较厚、栅栏叶肉组织厚度比例较大等适应略为干燥和较强光照的特征。  相似文献   

12.
沙伟  徐忠文  王晓琦  倪红伟   《广西植物》2006,26(6):583-588
通过石蜡切片制片,对采自三江平原5种生境下漂筏苔草的叶片进行了解剖学观察和研究。结果表明:5种生境下漂筏苔草的叶片具有相同结构,都是由表皮、叶肉和叶脉三部分构成的。但不同水深对叶片的解剖结构产生了一定影响,随着水分的增加,植物叶片的维管束个数和厚度、叶片厚度、导管直径和气腔直径均呈现上升趋势。以上结构变化是植物适应湿生环境的典型特征。  相似文献   

13.
BACKGROUND AND AIMS: Domatia are small organs usually found in the axils of major veins on the underside of leaves and, although they have received wide attention from ecologists, few detailed reports exist on their anatomy or development. This study is focused on the domatia of Cinnamomum camphora (Lauraceae) and is the first comparative study on the anatomy and development of the different shapes of domatia within a single plant. METHODS: Four types of domatia in C. camphora leaves were observed on paraffin sections under a microscope. KEY RESULTS: The domatia consisted of six histological parts: the upper epidermis, the upper mesophyll tissue, spongy tissue, the lower mesophyll tissue, the tissue filling the rim opening, and the lower epidermis. They differed from the non-domatial lamina mainly in the cell structure of the upper and lower mesophyll tissue and the rim tissue. Differences in domatium shapes were mainly associated with differences in the structure of the upper mesophyll and in the number and size of the rim tissue cells. Differences in the development of domatium types were observed in terms of initiation timing, differentiation of the upper mesophyll cells and degree of rim tissue development. CONCLUSIONS: In domatia, active anticlinal division in the lower mesophyll cells, as compared with the upper mesophyll cells, was coordinated with dynamic growth of rim tissue cells and resulted in cavity formation. The anatomical or developmental differences among the four types of domatia were related to the positions of the domatia within a leaf. In terms of the ecological implications, the major anatomical difference between the domatia used by herbivorous and carnivorous mites was in the development of the rim tissue.  相似文献   

14.
Certain anatomical characters of Jaumea carnosa, a salt marsh plant, which are diagnostic, adaptive, or otherwise important for an ecological anatomy study are described. The characters which follow are noteworthy. The plant has a sympodial construction forming an extensively branched rhizome system, and erect lateral shoots which eventually become prostrate. The leaves have very few, and only moderately developed succulent characters, such as: poorly defined palisade tissue, central mesophyll cells which are slightly enlarged anticlinally, and a complete lack of sclerification in the mesophyll. A continuous schizogenous canal system lined with epithelial cells lies in the ground tissues of all stem forms and leaves. The phellem is composed of thin-walled, only lightly suberized cells. Very broad parenchymatous areas develop in the secondary tissues of the rhizome, associated with a slowing of vascular cambial activity which creates depressions in the axis. Adventitious roots arise from ground tissues close to the primary xylem and from interfasicular regions close to the primary phloem in the rhizomes.  相似文献   

15.
山东滨海盐生植物叶结构的比较研究   总被引:10,自引:0,他引:10  
通过对11科14属14种滨海盐生植物的叶焉结构的比较研究表明:(1)生长在同一盐生环境中的14种植物,其中片具有许多结构的共同适应特征,如表皮细胞大小不等,外切向壁外突;栅栏组织发达;存在结晶细胞,单宁细胞和贮水细胞;机械绷带和维管组织都不发达等。  相似文献   

16.
Brassavola inhabits a wide altitude range and habitat types from Northern Mexico to Northern Argentina. Classification schemes in plants have normally used vegetative and floral characters, but when species are very similar, as in this genus, conflicts arise in species delimitation, and alternative methods should be applied. In this study we explored the taxonomic and phylogenetic value of the anatomical structure of leaves in Brassavola; as ingroup, seven species of Brassavola were considered, and as an outgroup Guarianthe skinneri, Laelia anceps, Rhyncholaelia digbyana and Rhyncholaelia glauca were evaluated. Leaf anatomical characters were studied in freehand cross sections of the middle portion with a light microscope. Ten vegetative anatomical characters were selected and coded for the phylogenetic analysis. Phylogenetic reconstruction was carried out under maximum parsimony using the program NONA through WinClada. Overall, Brassavola species reveal a wide variety of anatomical characters, many of them associated with xeromorphic plants: thick cuticle, hypodermis and cells of the mesophyll with spiral thickenings in the secondary wall. Moreover, mesophyll is either homogeneous or heterogeneous, often with extravascular bundles of fibers near the epidermis at both terete and flat leaves. All vascular bundles are collateral, arranged in more than one row in the mesophyll. The phylogenetic analysis did not resolve internal relationships of the genus; we obtained a polytomy, indicating that the anatomical characters by themselves have little phylogenetic value in Brassavola. We concluded that few anatomical characters are phylogenetically important; however, they would provide more support to elucidate the phylogenetic relantionships in the Orchidaceae and other plant groups if they are used in conjunction with morphological and/or molecular characters.  相似文献   

17.
Previous work has shown that the octopine synthase (ocs) gene encoded by the Agrobacterium tumefaciens Ti-plasmid contains an upstream activating sequence necessary for its expression in plant cells. This sequence is composed of an essential 16-bp palindrome and flanking sequences that modulate the level of expression of the ocs promoter in transgenic tobacco calli. In this study, we have used RNA gel blot analysis of RNA extracted from transgenic tobacco plants to show that the octopine synthase gene is not constitutively expressed in all plant tissues and organs. This tissue-specific pattern of expression is determined, to a large extent, by the 16-bp palindrome. Histochemical analysis, using an ocs-lacZ fusion gene, has indicated that the 16-bp palindrome directs the expression of the ocs promoter in specific cell types in the leaves, stems, and roots of transgenic tobacco plants. This expression is especially strong in the vascular tissue of the leaves, leaf mesophyll cells, leaf and stem guard cells, and the meristematic regions of the shoots and roots. Sequences surrounding the palindrome in the upstream activating sequence restrict the expression of the ocs promoter to fewer cell types, resulting in a reduced level of expression of beta-galactosidase activity in the central vascular tissue of leaves, certain types of leaf trichomes, and the leaf primordia.  相似文献   

18.
The genus Cymbidium (Orchidaceae) exhibits distinctive ecological diversification and occurs in terrestrial, epiphytic, and lithophytic life forms. One species, Cymbidium macrorhizon , lacks foliage leaves and has a strongly mycoparasitic existence. Correlation between habitat differentiation and anatomical characters was tested for 21 species of Cymbidium and its putative sister groups. Although hypostomaty characterizes the genus, C. canaliculatum shows amphistomaty. Ecological preference of this species indicates that amphistomaty is likely adapted to intensive insolation. Four types of subepidermal foliar sclerenchyma were found. Two forest floor species, C. goeringii and C. lancifolium as well as the mycoparasitic C. macrorhizon , do not have this sclerenchyma. In this genus, development of sclerenchyma is correlated with the degree of epiphytism. Palisade mesophyll evolved in Cymbidium section Cymbidium . As members of this section grow on isolated trees in tropical lowland forests or on rocks, the differentiation of palisade tissue is probably correlated with immigration to high light habitats. With the exception of C. macrorhizon , stegmata were found in leaves and stems of Cymbidium . Furthermore, a few epiphytic species have stegmata in their roots; this is a curious feature rarely found in vascular plants. Subterranean rhizomes characterize terrestrial species, while ageotropic roots are found in some epiphytic species. Cymbidium macrorhizon shows peculiar features such as degeneration of stomata, anomocytic stomata, and lack of stegmata and sclerenchyma. This set of character transformations is probably correlated with the evolution of mycoparasitic existence. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 138 , 383–419.  相似文献   

19.
叶片作为植物与外界进行物质交换的桥梁,其解剖性状能够相互协调以应对外界环境对植物生长造成的不利影响,从而反映出植物对环境变化所采取的适应策略。通过对黄土高原不同植被带(森林草原带、典型草原带、荒漠草原带)草地群落中常见115种植物(包括单子叶植物,双子叶植物,木本植物和草本植物四种功能型植物)叶片进行取样,并运用石蜡制片技术和光学显微技术获得叶片解剖性状(包括表皮厚度、栅栏组织厚度、海绵组织厚度、叶肉厚度和叶片厚度),旨在研究不同植被带内草地植物叶片解剖性状的变异规律及其与群落内物种相对优势度之间的关系,为黄土高原植被恢复和生态环境改善提供理论依据。结果表明:(1)沿着干旱梯度,从森林草原带、典型草原带到荒漠草原带,除叶肉厚度外,植物各叶片解剖性状值均呈现增大趋势,表明干旱地区叶片的旱生结构特征明显。(2)不同功能型植物叶片解剖性状与环境因子的关系各异。木本植物和草本植物的栅栏组织厚度和栅海比均与降水和土壤养分呈显著负相关关系(P<0.05)。同时,木本植物的叶片厚度与水分呈显著负相关关系(P<0.05),而草本植物表皮厚度仅与土壤养分呈显著负相关关系(P<0.05)...  相似文献   

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