中国鸢尾兰属(兰科)植物二新记录种

该文报道了兰科(Orchidaceae)鸢尾兰属(Oberonia Lindl.)2个中国新记录种,即心唇鸢尾兰(O. orbicularis Hooker f.)和凭祥鸢尾兰(O. delacourii Gagnep.)。其中,心唇鸢尾兰(O. orbicularis)与国内分布的全唇鸢尾兰(O. integerrima)和扁葶鸢尾兰(O. pachyrachis)均较为相似,但该种花葶中下部两侧具狭翅,不与叶合生,唇瓣边缘具明显的啮蚀状齿或细流苏状,先端中部具明显凹缺,可明显区别。心唇鸢尾兰(O. orbicularis)于2013年首次发现于云南省勐腊县,为中国新记录种。凭祥鸢尾兰(O. delacourii)与剑叶鸢尾兰(O. ensiformis)最为相近,但前者唇瓣中裂片先端小裂片近方形,小裂片先端边缘具流苏状齿,可明显区别于后者。凭祥鸢尾兰自1929年发表以来,除模式产地老挝外,至今未见新分布点的报道,为中国新记录种。文中提供了两个新记录种的形态特征描述,凭证标本存放于中国科学院华南植物园标本馆(IBSC)。     

中国兰科二新记录种

报道了中国兰科二新记录种：小馥兰(Phreatia elegans Lindl.),其主要特征是萼囊囊状,花梗和子房波状弯曲,唇瓣有爪与蕊柱足相连,唇盘有毛;镰叶鸢尾兰(Oberonia falcate King et Pantl.)与O. angusti- folia Lindl.类似,但本种的唇瓣明显三裂,中裂片先端二裂而易区别。     

中国石斛属(兰科)植物新资料

在西藏开展兰科植物资源调查过程中,发现了2种石斛属(金石斛组)物种,通过文献和标本的查阅之后,分别确定为麦氏金石斛(Dendrobium macraei Lindl.)和西藏金石斛(D. ritaeanum King & Pantl.),两者均为中国首次记录。其中,麦氏金石斛与流苏金石斛(D. plicatile Lindley)近似,不同之处在于前者唇瓣中裂片边缘全缘,中裂片具2条纵脊,并仅延伸至唇瓣中部,先端凹; 西藏金石斛虽然植株与狭叶金石斛[D. angustifolium (Blume)Lindl.]近似,但该种花很小,萼片和花瓣不具紫色条纹且唇瓣长达1.4 cm,侧裂片三角形,花期时容易区分。同时,该文还提供了该2种石斛属植物详细的形态特征描述以及解剖图版等资料,凭证标本保存于西藏农牧学院标本馆。该发现丰富了中国兰科植物本底资料以及潜在药用植物资源储备,对中国兰科植物的生物多样性研究和药用兰科资源的调查具有重要意义。     

中国万代兰属(兰科)一新记录种——双色万代兰

该文报道了在中国西藏林芝地区墨脱县发现的中国兰科(Orchidaceae)万代兰属(Vanda W. Jones ex R. Br.)一新记录种——双色万代兰(Vanda bicolor Griff.)。双色万代兰与白柱万代兰(V. brunnea Rchb. f.)的形态较近似,但前者唇瓣中裂片正面粉色或黄绿色,不具纹,先端稍开裂,易与后者相区别。同时还描述了该新记录种的形态特征,并提供了彩色图版。该研究为兰科植物的研究提供了基础,对丰富我国兰科植物物种多样性具有一定意义。     

中越带唇兰, 中国带唇兰属(兰科)一新记录

报道了中国兰科（Orchidaceae）植物一新记录种：中越带唇兰（Tainia acuminata Averyanov）,并提供形态描述及彩色图片。该种与心叶带唇兰（T.cordifolia Hook.f.）相近,不同在于萼片与花瓣均为狭披针形,唇瓣无侧裂片,阔披针形,渐尖,唇瓣边缘在中上部波状卷曲,唇盘具3条不明显的脊。     

中国隔距兰属(兰科)一新记录(英文)

隔距兰属(Cleisostoma Bl.)是兰科植物中较大的一个属,约有100种,广泛分布于热带、亚热带地区。中国约有16种,其中4种为特有。该文报道了该属一中国新记录——二齿叶隔距兰[Cleisostoma aspersum(Rchb.f.)Garay],并提供描述和照片,目前该种仅见于云南。与近缘种类相比,本种具有以下鉴别特征:叶齿状二裂;唇瓣中裂片肥厚,前缘钝;蕊喙圆锥状,先端歪斜;药帽喙状等。在花部形态上,该种与Cleisostoma discolor Lindl.相似,然而后者的唇瓣中裂片明显较薄,匙状方形,并且具有啮齿状边缘,易于区别。     

西藏兰科新记录

报道了兰科（Orchidaceae）高山铠兰［Corybas himalaicus (King & Pantl.) Schltr.］和山珊瑚（Galeola faberi Rolfe）在中国西藏自治区的分布新记录。高山铠兰形态上因唇瓣先端边缘齿蚀状,花瓣与侧萼片在基部贴生,长7～8 mm,距暗红色而区别于铠兰属其他种;山珊瑚形态上因萼片狭椭圆形,唇瓣上散生褶片状附属物,边缘不规则齿状而区别于山珊瑚属其他种。凭证标本存放于广西药用植物园标本馆（GXMG）。     

中国大陆鸢尾兰属(兰科)二新记录种

首次报道了中国大陆兰科(Orchidaceae)鸢尾兰属(Oberonia)二新记录种:密花鸢尾兰[O. seidenfadenii (H. J. Su) Ormerod]和齿唇鸢尾兰(O. segawae T. C. Hsu & S. W. Chung),并提供了它们的形态特征描述。     

中国兰科植物四个新记录种

报道了中国兰科植物四个新记录种,反瓣叉柱兰(Cheirostylis thailandica),短茎对叶兰(Listerabrevi-caulis),凹唇石仙桃(Pholidota recurva),绿花大苞兰(Sunipia annamensis)。短茎对叶兰(Listera brevicaulis)二枚叶贴地着生,唇瓣先端二裂,裂片下翻并靠合;凹唇石仙桃(Pholidota recurva)的假鳞茎圆柱形,首尾相连,花偏向一侧,花序在中部向下弯,唇瓣前端略凹陷;绿花大苞兰(Sunipia annamensis)的花序长于叶,唇瓣心形,肉质,边缘向上翻卷。     

中国兰科二新记录种

报道了中国西藏兰科植物二新记录种:无叶沼兰(Crepidium aphyllum(King&Pantl.)A.N.Rao)和矮生白点兰Thrixspermum pygmaeum(King&Pantl.)Holttum。无叶沼兰和本属另一腐生种C.saprophytum(King&Pantl.)A.N.Rao的主要区别为假鳞茎圆柱形,唇瓣平展,顶端圆形,中萼片直立。矮生白点兰与T.masciflorum A.S.Rao&J.Joseph相似,但本种花序短于叶,苞片螺旋排列、花瓣匙形、唇瓣下凹且3裂、中裂片顶端下凹、胼胝体有毛。     

Rhizosphere-Bacterial Community in <Emphasis Type="Italic">Eperua falcata</Emphasis> (Caesalpiniaceae) a Putative Nitrogen-Fixing Tree from French Guiana Rainforest

The rainforest of French Guiana is still largely unaffected by human activity. Various pristine sites like the Paracou Research Station are devoted to study this tropical ecosystem. We used culture-independent techniques, like polymerase chain reaction-temperature gradient gel electrophoresis, and construction of clone libraries of partial 16S rRNA and nifH genes, to analyze the composition of the bacterial community in the rhizosphere of mature trees of Eperua falcata and Dicorynia guianensis, both species within the Caesalpiniaceae family. E. falcata is one of the more abundant pioneer tree species in this ecosystem and so far, no root nodules have ever been found. However, its nitrogen-fixing status is regarded as “uncertain”, whereas D. guianensis is clearly considered a non-nitrogen-fixing plant. The rhizospheres of these mature trees contain specific bacterial communities, including several currently found uncultured microorganisms. In these communities, there are putative nitrogen-fixing bacteria specifically associated to each tree: D. guianensis harbors several Rhizobium spp. and E. falcata members of the genera Burkholderia and Bradyrhizobium. In addition, nifH sequences in the rhizosphere of the latter tree were very diverse. Retrieved sequences were related to bacteria belonging to the α-, β-, and γ-Proteobacteria in the E. falcata rhizoplane, whereas only two sequences related to γ-Proteobacteria were found in D. guianensis. Differences in the bacterial communities and the abundance and diversity of nifH sequences in E. falcata rhizosphere suggest that this tree could obtain nitrogen through a nonnodulating bacterial interaction.     

呼伦贝尔黄花苜蓿MfMYB30基因的克隆及表达分析

该研究在呼伦贝尔黄花苜蓿(Medicago falcata L. cv. Hulunbuir)转录组测序基础上,通过RT PCR方法克隆获得了MfMYB30基因,并通过生物信息学和表达分析进行初步研究,为深入研究MfMYB30基因的功能和开发利用奠定基础。结果表明：(1)成功克隆获得呼伦贝尔黄花苜蓿MfMYB30基因,其ORF序列长为957 bp,编码318个氨基酸,相对分子质量为86.85 kD,理论等电点为5.11。MfMYB30蛋白为疏水性蛋白,无跨膜结构,无信号肽序列。(2)系统进化分析表明黄花苜蓿MfMYB30蛋白与紫花苜蓿MsMYB4、拟南芥AtMYB30、木豆CcMYB30、蒺藜苜蓿MtMYB30和大豆GmMYB60聚为一个类群,亲缘关系较近。(3)实时荧光定量PCR结果显示,MfMYB30在黄花苜蓿模拟刈割不同天数后的相对表达量呈先降低后升高的趋势,在刈割7 d后相对表达量达到峰值。(4)通过在拟南芥原生质体亚细胞定位分析发现,该蛋白定位于细胞核。研究推测,MfMYB30基因可能在黄花苜蓿刈割或放牧胁迫响应过程中发挥重要调控作用。     

Human impacts on Persoonia falcata. Perspectives on post-contact vegetation change in the Keep River region, Australia, from contemporary vegetation surveys

Persoonia falcata R. Br. and Buchanania obovata Engl. seeds are consistently preserved in abundance from archaeological sites across the Keep River region from 3500 b.p. up until the contact period. Although artefacts continued to be deposited after establishment of the pastoral industry, remains of these two plant species disappear in the upper levels of all excavated deposits. The contemporary vegetation in the vicinity of these sites appears to lack P. falcata, although B. obovata remains in abundance. These observations raise questions regarding (1) the impact of changing land-use and fire regimes, (2) the impact of Aboriginal land management on particular plant species and (3) the reorientation of Aboriginal site use across the region after settlement. These issues are explored in this paper using a comparative analysis of stand structure of the contemporary vegetation around previously excavated sites, as well as from published information on recent regional fire history. Results show improved recruitment of P. falcata (that is, seedlings are recruited into adult life stages) in the only site where Aboriginal people have re-introduced customary management. Both the timing of burning and significant unburnt periods appear important to the post-contact decline and also in the future success of populations of P. falcata in the region.     

Subfossil remains of an unknown chydorid (Anomopoda: Chydoridae) from Finland

Subfossil remains of an unknown chydorid taxon were found in sediments of three lake basins in Finland. Two of the sites lie in southern Finland and one in NW Finnish Lapland. Similar remains are also known from four lakes in eastern Finland. The headshields are small, with a broadly rounded posterior margin and an attenuated rostrum. The headshields resemble those of Rhynchotalona falcataSars, but have a unique pore arrangement. There is one oval median pore near the posterior margin and two lateral pores which are displaced quite far in position. The shell is very small and has faint, longitudinal striae. Also, unknown postabdomens were found. These resemble postabdomen of R. falcatain shape but had 5–6 pairs of teeth instead of the 2 seen in R. falcata. The age of the remains varies between ca. 8500 ¹⁴C yr BP and recent decades. The species appears to have been present in the entire country during most of the Holocene. On the basis of the pore arrangement, the new species cannot be put into any previously known genus. A tentative name Unapertura latensn. sp. is suggested until intact specimens are found and described.     

Root responses of flood-tolerant and flood-sensitive tree species to soil redox conditions

Summary Under controlled rhizotron conditions, roots of Taxodium distichum L., Quercus lyrata Walt, and Q. falcata var. pagodaefolia Ell. were subjected to low soil redox potentials. Root elongation was inhibited at low soil redox potentials. In T. distichum, redox potentials below +200 mV resulted in a significant inhibition of root elongation. In Q. falcata var. pagodaefolia and Q. lyrata, redox potentials below +350 mV resulted in complete cessation of root growth. Studies on root anatomy indicated that low soil redox potenials resulted in a changed cellular structure in the cortex of T. distichum. However, little change was noted in stress roots of oak species. Alcohol dehydrogenase activity in T. distichum roots was approximately doubled compared to control plants, indicating stimulated alcoholic fermentation. In T. distichum, alcoholic fermentation and anatomical changes contribute to flood tolerance but oak species lack these characteristics.     

Evaluation of the effect of three growth regulators in the germination of <Emphasis Type="Italic">comparettia falcata</Emphasis> seeds under <Emphasis Type="Italic">in vitro</Emphasis> conditions

Summary The effect of 3-indoleacetic acid (IAA), 6-furfurylaminopurine (kinetin), and gibberellic acid (GA₃) on germination of the orchid Comparettia falcata was evaluated in a factorial experiment (4×4×4) with Murashige and Skoog (1962) basal medium. It was established that seeds of this orchid could be maintained under aseptic conditions as long as the necessary nutrients and appropriate concentrations of growth regulators were provided. Of the three growth regulators used, IAA significantly decreased seed germination of Comparettia falcata. There was a synergistic effect in the kinetin:GA₃ combination that produced a positive response in both percentage seed germination and development of seedlings. This study describes a single medium-based protocol able to achieve more than 160000 seedlings within 21 wk, starting from a single capsule, sufficient for both large-scale propagation and in vitro conservation of this threatened orchid.     

Introduction of asymbiotically propagated seedlings of <Emphasis Type="Italic">Cephalanthera falcata</Emphasis> (Orchidaceae) into natural habitat and investigation of colonized mycorrhizal fungi

Asymbiotic seedling propagation and introduction of seedlings into a natural habitat were achieved for Cephalanthera falcata. For immature seeds collected 65 days after pollination, high germination rate (av. 50%) was achieved on Hyponex agar medium plates. Root development occurred in about 10% of the protocorms 5 months after seed sowing. Rooted protocorms were transferred to a culture bottle containing 100 ml of the Hyponex agar medium and incubated continually. In about 30% of the transferred individuals, shoot height reached 1.5–2 cm 8 months after the transfer. After acclimatization in wet vermiculite at 4°C for 6 months, 135 individuals were planted in a natural stand of C. falcata in mid February 2001. Shoot appearance rate was 44.4% at the first year and flowering was noted in some plants. At the fifth year, shoots with an average height of 21.6 cm still appeared in four plants, and flowering was noted in three of them. Colonization of mycorrhizal fungi was examined in two of them as well as one wild plant, in which the mycorrhizal fungi were identified to be in Thelephoraceae or Russulaceae. These fungi are known to form ectomycorrhiza with trees, and thus a tripartnership symbiosis consisting of C. falcata, mycorrhizal fungi and trees was suggested. The involvement of ectomycorrhizal fungi might be the reason for the low survival rate in the field experiment, because the distribution of ectomycorrhizal fungi relevant to this orchid is assumed to be uneven. The possibility of introducing artificially propagated orchids into natural habitats was discussed.     

Capnodium citri: The sooty mold fungi comprising the taxon concept

The common use of the name Capnodium citri to represent several species of sooty mold fungi is reviewed. Analysis of sooty mold specimens from Citrus in Florida found the species Antennariella californica and Chaetobolisia falcata with spherical fruitbodies and Caldariomyces fumago and Polychaeton citri with elongate fruitbodies. It is recommended that use of the name Capnodium citri for sooty mold on Citrus and ornamental plants is to be avoided because of its use for a number of species and on nomenclatural grounds. This revised version was published online in June 2006 with corrections to the Cover Date.