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1.
 Floral structure and development of representatives of Asteliaceae, Blandfordiaceae, Boryaceae, Doryanthaceae, and Hypoxidaceae, all members of the `lower' Asparagales, were studied comparatively. The results are discussed in the light of new molecular systematic studies, but also with regard to established morphological characters in related groups. Stamen shape varies considerably within and between taxa: the shape of anthers is from X-shaped, sagittate to non-sagittate, they are either latrorse or introrse, basifixed, centrifixed or dorsifixed. Gynoecia are syncarpous up to the stigmatic region in all taxa. Ovaries of Doryanthaceae and Hypoxidaceae are inferior, but they are superior in Asteliaceae, Blandfordiaceae and Boryaceae. All ovaries have at least a short synascidiate zone. With the exception of Astelia alpina (Asteliaceae), the ovaries are trilocular. Ovaries of Asteliaceae contain mucilage, which is secreted from trichomes on the funicle and on the placenta. Although flowers are polysymmetric at anthesis, they are monosymmetric in earliest stages with a developmental gradient from adaxial to abaxial. Perianth organs arise individually from either a concave (taxa with inferior ovary) or convex (taxa with superior ovary) apex. Hypoxidaceae have pollen flowers with free stamens. One species, Curculigo capitulata, has Solanum-type flowers with postgenitally united stamens. It is most probably pollinated by buzzing bees. All other taxa have nectariferous flowers with internal or external septal nectaries. Received February 5, 2001 Accepted June 20, 2001  相似文献   
2.
A gynostemium, comprising stamen filaments adnate to a syncarpous style, occurs in only threc groups of monocots: the large family Orchidaceae (Asparagales) and two small genera Pauridia (Hypoxidaceae: Asparagales) and Corsia (Corsiaceae, probably in Liliales), all epigynous taxa. Pauridia has actinomorphic (polysymmetric) flowers, whereas those of Corsia and most orchids are strongly zygomorphic (monosymmetric) with a well-differentiated labellum. In Corsia the labellum is formed from the outer median tepal (sepal), whereas in orchids it is formed from the inner median tepal (petal) and is developmentally adaxial (but positionally abaxial in orchids with resupinate flowers). Furthermore, in orchids zygomorphy is also expressed in the stamen whorls, in contrast to Corsia. In Pauridia a complete stamen whorl is suppressed, but the 'lost' outer whorl is fused to the style. The evolution of adnation and zygomorphy are discussed in the context of the existing phylogenetic framework in monocotyledons. An arguably typological classification of floral terata is presented, focusing on three contrasting modes each of peloria and pseudopeloria. Dynamic evolutionary transitions in floral morphology are assigned to recently revised concepts of heterotopy (including homeosis) and heterochrony, seeking patterns that delimit developmental constraints and allow inferences regarding underlying genetic controls. Current evidence suggests that lateral heterotopy is more frequent than acropetal heterotopy, and that full basipetal heterotopy does not occur. Pseudopeloria is more likely to generate a radically altered yet functional perianth, but is also more likely to cause acropetal modification of the gynostemium. These comparisons indicate that there are at least two key genes or sets of genes controlling adnation, adaxial stamen suppression and labellum development in lilioid monocots; at least one is responsible for stamen adnation to the style (i.e. gynostemium formation), and another controls adaxial stamen suppression and adaxial labellum formation in orchids. Stamen adnation to the style may be a product of over-expression of the genes related to epigyny (i.e. a form of hyper-epigyny). If, as seems likely, stamen-style adnation preceded zygomorphy in orchid evolution, then the flowers of Pauridia may closely resemble those of the immediate ancestors of Orchidaceae, although existing molecular phylogenetic data indicate that a sister-group relationship is unlikely. The initial radiation in Orchidaceae can be attributed to the combination of hyper-epigyny, zygomorphy and resupination, but later radiations at lower taxonomic levels that generated the remarkable species richness of subfamilies Orchidoideae and Epidendroideae are more likely to reflect more subtle innovations that directly influence pollinator specificity, such as the development of stalked pollinaria and heavily marked and/or spur-bearing labella.  相似文献   
3.
4.
Isolation of the known diglucoside of (E)-1,5-bis(3′,4′-dihydroxyphenyl)pent-4-en-1-yne (hypoxoside) from Hypoxis rooperi is described. In vivo tests indicate low toxic properties. A general synthesis for the introduction of the pentenyne link between two aromatic rings is described.  相似文献   
5.
仙茅中两个新的环阿尔廷醇型三萜皂苷   总被引:2,自引:0,他引:2  
从仙茅(Curculigo orchioides)中分离得到2个新的环阿尔廷醉型三萜皂苷,通过波诺分析鉴定了它们的化学结构,即3β,11α,16β—三羟基环阿尔廷烷-24-酮-3-O-[β-D-吡喃葡糖(1→3)-β-D-吡喃葡糖(1→2)-β-吡喃葡糖]-16-O-α-L-阿拉伯糖苷(1)和(24S)-3β,11α,16β,24-四经基环阿尔廷烷-3-O-[β-D-吡喃葡糖(1→3)-β-D-吡喃葡糖(1→2)-β-D-吡喃葡糖]-24-O-β-D-吡喃葡糖苷(2)。  相似文献   
6.
Two new norlignan glycosides, molinerioside D (5) and molinerioside E (9), were isolated from the methanol extract of fresh leaves of Molineria latifolia. Their structures were determined using spectroscopic evidence, such as 1D and 2D NMR and HR-ESI-MS studies. The structure of molinerioside D (5) was determined to be a norlignan glycoside with a C6-C5-C6 skeleton, while the structure of molinerioside E (9) was determined to be a glucosyl-fused norlignan derivative. In addition to the new compounds, twenty known compounds were found in the extract of M. latifolia fresh leaves.  相似文献   
7.
从仙茅(Curculigo orchioides Gaertn.)根茎中分离得到4个化合物,分别为curculigoside(1)、curculigoside B(2)、curculigoside C(3)和2,6-dimethoxyl benzoic acid(4).其中,化合物3为一个新的酚苷类成分,命名为仙毛苷丙,用现代波谱方法(1H-NMR、13C-NMR、2D-NMR和ESI-MS)鉴定其化学结构为5-羟基-2-O-β-D-吡喃葡萄糖基苄基-3′-羟基-2′,6′-二甲氧基苯甲酸酯.  相似文献   
8.
An efficient and reproducible method for inducing a large number of bulblets from rhizome explants of Curculigo orchioides Gaertn., an endangered medicinal herb, has been developed. The rhizome pieces, measuring about 1 × 1 cm (length × width), were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of the cytokinins 6-benzylaminopurine, kinetin, and thidiazuron (TDZ) alone or in combination with 1-naphthalene acetic acid or indole-3-butyric acid (IBA). Of the three cytokinins used, TDZ at 7 μM gave the maximum response, with 82% of the cultures responding with an average number of 15.4 bulblets per explant. The addition of auxins with cytokinin considerably increased the response. The optimum induction occurred on MS medium supplemented with 7 μM TDZ and 0.5 μM IBA. On this medium, 88% of the cultures responded with an average number of 21.4 bulblets per explant. Experiments were also carried out to investigate the role of the sugars sucrose, mannose, and glucose along with 7 μM TDZ and 0.5 μM IBA. The results indicate that sucrose and mannose at particular concentrations have critical roles in promoting in vitro bulblet induction. The maximum result was observed on MS medium supplemented with 7 μM TDZ, 0.5 μM IBA, and 200 mM mannose. On this medium, 97% of the cultures responded with an average number of 26.8 bulblets per culture. Several secondary bulblets developing from the leaf blades of primary bulblets were produced when the latter were transferred to MS basal medium for further development. Out of the 45 bulblets transferred to soil, 40 survived. This protocol can be used for the rapid micropropagation of this endangered medicinal herb.  相似文献   
9.
广西单子叶植物五新种   总被引:3,自引:0,他引:3       下载免费PDF全文
方鼎  覃德海   《广西植物》1996,16(1):3-8
广西单子叶植物五新种方鼎,覃德海(广西中医药研究所,南宁530022)关键词仙茅科,球序仙茅,兰花蕉科,长萼兰花蕉,姜科,裂舌姜,少斑姜,长腺姜FIVENEWSPECIESOFMONOCOTYLEDONEAEFROMGUANGXI¥FangDing;...  相似文献   
10.
田琴  段涵宁  王云强  李海涛  李璐 《广西植物》2022,42(10):1661-1674
为澄清仙茅科属间界限不清的分类学问题,该文以中国仙茅科3属5种植物为研究对象,利用显微镜、扫描电镜和石蜡切片技术,观察了其叶形态、叶表皮显微特征和叶解剖特征。结果表明:(1)叶形态有小型平整叶、中型波状叶、大型折扇状叶三种。(2)叶表皮毛状体结构为单细胞单列,可分为长柔毛、糙伏毛和星状柔毛三类。(3)叶表皮细胞有六边形和五边形,气孔为平列型和椭圆形,气孔大小和气扎密度呈反比。(4)叶表皮蜡质纹饰有光滑、颗粒、屑状和壳状四类。(5)叶中脉横切面分为平整型和龙骨型,维管束有圆形和椭圆形,叶表皮厚度与表皮细胞具有正相关性。对5种植物的叶形态和叶解剖特征比较分析认为,一些特征组合有助于理解仙茅科属间的亲缘关系和物种鉴定,支持大叶仙茅属独立于仙茅属。  相似文献   
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