国产三脊毛兰的考订

基于对活体植物的观察和原始文献的研究,对国产三脊毛兰(Eria cristata)Rolfe进行了考订.本种的萼片和花瓣白色,唇瓣黄色,两侧边缘和唇盘的颜色较深;唇盘具3条被黄色毛突的褶片,易于和其近缘种相区别.     

毛兰属植物化学成分及药理活性研究进展

毛兰属植物由于近年来同属于兰科的石斛属植物的过度采挖,而取代名贵中药石斛类作为药材应用。为了了解其化学成分及能否替代石斛应用,本文对毛兰属植物的化学成分及药理活性研究进展进行了综述。目前毛兰属植物研究所涉及的种类仅5种,从该属植物中分离出化学成分13种,包括菲类、9,10-二氢菲类及二聚体、联苄、甾体和脂肪族化合物等结构类型。药理研究表明,一些成分如毛兰素和毛兰菲在抗肿瘤和抗氧化等方面显示了较好的活性。开展毛兰属植物的研究,对发现新的药用活性成分及资源保护有重要意义。     

Eria mêdogensis,a Probably Peloric Form of Eria Coronaria,with a Discussion on Peloria in Orchidaceae

Eria mêdogensis S. C. Chen et Tsi was recently found in southeastern Tibet, several specimens of which have been collected by various botanists since 1980. This is a “normal”entity with its habit very similar to that of Eria coronaria, from which it differs by having aregular perianth and longer bracts. We think it probable that this new entity is a peloric formof Eria coronaria. Peloria (or pelory) is a type of floral abnormality, which is found in many zygomorphicflowered taxa. It was first detected by Linnaeus (1744) in Linaria vulgaris, and then by othersin Labiatae, Orchidaceae, etc. However, it is still an open question how to explain it theoretically and how to treat it taxonomically. In Orchidaceae, so far as our knowledge is concerned, peloria has been encountered in noless than 21 genera. In most cases, peloric flowers are found sporadically on an occassional plant,as seen in Cypripedium reginae and Eria oblitterata. Sometimes, however, peloric form may occurcoexisting with normal-flowered form in one and the same species, as seen in Dendrobium tetrodon and Epipogium roseum. They are both abnormally peloric forms. It would not result innaming or renaming a plant taxonomically, whether the appearance of abnormally regular flowers on a normal-flowered inflorescence, or of abnormal-flowered individuals in normal-flowered species. In Phragmipedium lindenii, however, the case is different. It is quite “normal” andeven of wider distribution than its nonpeloric allies P. wallisii and P. caudatum, from whichit has once been considered to be derived. This is a normally peloric form. Whether it is areversal or not, the appearance of a “normally” peloric taxon may be taken for a leap in theprocess of evolution. Taxonomically, we had better treat it as a separate species, especially when its origin is uncertain. For example, the entity just mentioned had been treated as a peloric va riety of Phragmipedium caudatum (var. lindenii) until 1975, when Dressler & Williams recognized it as an independent species based on the fact that its nonpeloric flowers occassionally foundin a peloric population in Jungurahua of Ecuador are dissimilar in lip to those in P. caudatum. Garay (1979) considered it to be a peloric form of P. wallisii but maintained it at thespecific level. This is indeed a good example of taxonomic treatment of normally peloric form. On the other hand, however, most of the regular-flowered entities in Orchidaceae are not peloric but rather primitive forms, such as Neuwiedia, Apostasia and Thelymitra, of which no less than 50 species have been reported since the eighteen century. They have never been regarded as peloric forms. Unfortunately, this has been neglected by some botanists. For instance, a hypothetically primitive orchid flower designed by Pijl & Dodson (1966) has a distinctly specialized lip with a short spur. In fact, in addition to the aforementioned genera we have some more examples of normally regular-flowered orchids. Among them Archineottia is the most interesting.This is a genus of four species, two of which are regular-flowered. Of special interest is that inthis genus and its ally, Neottia, one can find all steps of column evolution from a simple formwith stamen and style not fully united to a most complicated form in which they have well fused.Archineottia has a very primitive column, on which neither rostellum nor clinandrium is foundbut a terminal and undifferentiated stigma (Fig.2: 2, 4, 6, 8). In addition, there exists on theback of the column a thick ridge with its upper end joining the filament with which it is ofsame texture. It is obviously the lower part of the filament which has been adnate to the style (column). In Neottia, however, the column is much more advanced and very typical among thefamily. It has a very large rostellum and most complicated stigma structure (Fig. 10, 12, 14, 16,18). One of the most interesting examples is Neottia acuminata, in which the stigma evenbecomes lamellate and almost backwards clasps the erect rostellum, but the perianth is more orless regular with its lip entire and somewhat similar to, but shorter and wider than, the petals.In these two genera there are altogether three species, namely Archineottia gaudissartii, A microglottis and Neottia acuminata, possessing regular or nearly regular perianth (Fig. 2: 1, 3, 17).They are obviously not peloric forms. We can not imagine, indeed, that a complicated formlike Neottia acuminata or its allies would degenerate step by step into a simple form, and finallyinto a peloric form. Archineottia belongs to the subtribe Listerinae, which is closely related toLimodorinae, a rather primitivs subtribe with some genera possessing single pollen grain, relatively few and long chromosomes and monocotyledonous habit. Apparently, there is nothing surprising in the occurrence of some normally regular-flowered taxa, such as Archineottia, Diplandrorchis, Tangtsinia and Sinorchis, in these two primitive subtribes. Another instance is Aceratorchis, a genus formerly included in Orchis, from which it is distinguished by the entire lip which is more or less similar to the petals. Strictly speaking, however, its flowers are not truly regular. Two species have been described in this genus, but theywere recently considered as conspecific. Aceratorchis tschiliensis is widely distributed fromHebei through Qinghai and Sichuan to northwestern Yunnan. It is cross-pollinated and producesseeds efficiently. All these indicate its normally primitive taxon, instead of peloria. It may benoted here that Asia is rich in members of Orchidioideae, as well as its primitive representatives.The occurrence of a normally regular-flowered form in Asia, whether representing primitiveform of Orchis or Orchidioideae, is imaginable. In Orchidaceae, as mentioned above, regular flowers are not only found in some primitivetaxa and peloric forms, but also in a few advanced groups. For example, a close investigationby the senior author (Chen 1979) on Satyrium ciliatum revealed that this species has hermaphrodite, staminate and pistallate forms, for which no less than nine names have been published.The flowers of its pistallate form are almost regular, in which nothing is found but threesimilar petals and an elongate style with three stigmatic lobes at its top (Fig. 2: 19). It is interesting to note that floral reversions in Orchidaceae are not always in connectionwith peloria. For example, Epidendrum triandrum of North America represents another kindof reversion. It is a reversal to abnormal polymery of stamens and not to abnormal regularityof perianth. Like Phragmipedium lindenii, it is also hereditary. We may give it a new name“Polyandrism” or something else, but, in fact, there is no essential distinction of this kind of reversion from peloria. It deserves mentioning that most of the regular-flowered entities, including primitive, advanced and peloric ones, occur in Asia and Australasia, where the Orchidaceae may have originated as pointed out by some botanists. We have good reason to verify the primitiveness andnormality of many regular-flowered entities, but there exists no sufficient evidence for the impossible existances of normally regular-flowered species in those like Dendrobium, Eria, Lecanorchis, etc. For instance, Lecanorchis javanica, Dendrobium atavus and the new species describedhere are considered to be peloric forms, but it is only a conjecture, for no reason can be givenfor it. It is not impossible that some so-called peloric forms may prove to be truly primitive onesin the future. Of course, a closer investigation is needed. Summarizing the above, we may come to the following conclusions: 1. Regular or nearly regular perianth is a normal characteristic of orchids. It is chieflyfound in some primitive taxa and sometimes also in certain peloric forms and advanced groups.Regular-flowered entities may not necessarily be peloric forms. 2. There exist two different types of peloria in Orchidaceae. One is abnormal form, withits peloric flowers appearing at random. The other is “normal” form, with its individuals allpossessing peloric flowers. The latter is inheritable and can produce seeds efficiently, It wouldbe best to treat it as an independent species taxonomically, especially when its origin is uncertain. 3. Although peloria has been considered to he a reversal as a whole, conditions vary fromplant to plant. Some peloric forms have petal-like lip, and others have labellum-like petals.Sometimes the same plant produces different kinds of peloric flowers in different years, sometimespeloric flowers do not reappear upon the same plant. A few species can produce both peloricand normal individuals, but others produce peloric forms only. Peloria is in fact a term onlyused to cover the phase in which lip becomes similar to the petals. It is never all-embracing.We recognize the existance of peloria in Orchidaceae, but great care must be taken to distinguishtruly peloric form from normally primitive one. It must be admitted that what causes peloriaand even what is peloria are still problems awaiting solution. Acknowledgments: Our heartfelt thanks are due to Dr. Leslie A. Garay, Curator of theOrchid Herbarium of Oakes Ames, Botanical Museum of Harvard University, for his valuablesuggestions during the preparation of this paper. We are also indebted to the artists, Mrs. Chunrung Liu and Mr. Chao-zhen Ji of our department, for their preparing the fine drawings.     

足茎毛兰组培快繁技术研究

在足茎毛兰的组培快繁过程中,有机添加物10％的椰乳对原球茎的诱导有极显著影响;激素组合6-BA和NAA及配比10∶1对芽的诱导和增殖起明显的促进作用;一定浓度的IBA对足茎毛兰的壮苗生根起关键性作用;栽培基质的选择极大地影响足茎毛兰的移栽成活率.     

A new species of Malaxis (Orchidaceae) from Morelos, Mexico

A new species from the Mexican state of Morelos, Malaxis lyonnetii, is described and illustrated. It is similar to M. lepanthiflora but is distinguished by its much smaller flowers, distally uncinate basal lip lobes, and entire, rounded apical lip lobe.

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Resumen  Se describe e ilustra a Malaxis lyonnetii, una nueva especie del estado mexicano de Morelos. Esta especie es similar a M. lepanthiflora, de la que se distingue por las flores mucho menores, los lóbulos basales del labelo distalmente uncinados y el lóbulo apical del labelo entero y redondeado.

     

培养基与光照对沼兰种子非共生萌发的影响

近年来由于灭绝性采挖和生态环境的恶化,沼兰(Malaxis monophyllos)的自然资源遭到严重破坏,加上沼兰种子具有萌发缓慢和萌发率低的特性,已处于近危乃至易危的状态。为了繁殖和保护沼兰种质资源,利用添加2%蔗糖、3%活性炭和0.8%琼脂的Knudson C(KC)培养基,研究了萘乙酸(NAA)、6-苄基腺嘌呤(6-BA)、椰乳、香蕉泥、土豆泥和光照条件6种因素对沼兰种子非共生萌发的影响;同时通过光学显微镜和扫描电镜观察了种子的外部形态。结果显示,沼兰种皮细胞的平周壁方向结构平坦、没有纹络,但是沿着细胞垂周壁方向细胞壁较厚。通过正交试验设计和冗余分析,建立了沼兰种子非共生萌发的最佳方案,即在含有4.5mg·L–1NAA、10mg·L–16-BA、8%香蕉泥和3%土豆泥的KC培养基上光照条件(光照强度为20μmol·m–2·s–1,光周期为12h/12h)下萌发。该方案的种子萌发率在90%以上。     

中国大陆的一种植物新记录

1985年,我在参加由安徽省芜湖市科委、卫生局和九华山管理处联合组织的九华山植物资源调查中,采到一种兰科毛兰属植物,经鉴定系葡萄毛兰Eria reptans(Fr. et Sav.)Makino。本种只记载分布于日本和我国台湾岛,而在中国大陆是地理分布新记录。同时,毛兰属也是安徽省地理分布新记录的属。     

中国兰科植物三个新记录种

报道了中国兰科植物的三个新记录种,裂唇卷瓣兰(Bulbophyllum picturatum),长柄虾脊兰(Calan-the allizettei)和绿花毛兰(Eria lanigera)。裂唇卷瓣兰的中萼片全缘前部具一粒状附属物,唇瓣基部两侧具耳。长柄虾脊兰的中裂片非常小并具三条褶片。黄花毛兰的花黄绿色,唇瓣不裂。     

中国兰科植物新资料

报道了中国兰科(Orchidaceae)一新记录种——白苞石豆兰（Bulbophyllum albibracteum Seidenf.）;它的主要特征是花苞片白色;大且显著;外弯;边缘具细锯齿;萼片背面沿中脉具短毛;蕊柱齿直立细长;长达1 mm。鞍唇沼兰（Malaxis matsudai (Yamamoto) Hatusima）与全唇叉柱兰（Cheirostylis takeoi(Hayata) Schltr.）为中国大陆新记录。     

Embryology ofMalaxis saprophyta,with comments on the systematic position ofMalaxis (Orchidaceae)

InMalaxis saprophyta, anther wall development corresponds to the Monocotyledonous type. The uninucleate tapetum is of secretory type and the endothecium develops U- and V-shaped thickenings on the inner tangential and radial walls. Cytokinesis is simultaneous; tetrahedral, isobilateral and T-shaped tetrads are formed which are compactly aggregated in pollinia. At anthesis the microspore tetrads are 2-celled. The ovule is anatropous, bitegmic and both integuments are dermal in origin. A single hypodermal cell develops directly into a megaspore mother cell. Embryo sac development is predominantly monosporic and less often bisporic. Irrespective of the type of development, the mature embryo sac is 6-nucleate. Although double fertilization occurs, the primary endosperm nucleus degenerates. Embryogeny is of the Onagrad type. The mature embryo lacks differentiation into cotyledon, plumule and radicle. The reticulate seed coat is formed entirely by the outer layer of outer integument. There are three sterile and three fertile valves in the ovary. Although initially parenchymatous, the entire three sterile valves in the ovary and the upper half of the three fertile valves become sclerified after fertilization. The embryological characters support the disputed systematic position ofMalaxis within subtribeMalaxidinae ofEpidendreae.     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.