芳香石豆兰的繁殖生态学

芳香石豆兰(Bulbophyllum ambrosia)是分布于我国南方石灰岩山热带季节性雨林中的一种常见附生兰科植物, 附着生长于岩石或树干上, 野外监测发现其自然不结实。对芳香石豆兰繁殖生态学的研究表明, 不同于石豆兰属其他具有蝇类传粉综合征的种类, 其花具有香味和花蜜, 中华蜜蜂(Apis cerana cerana)是芳香石豆兰唯一的有效传粉者, 具有较高的访问频率, 自然种群中有较高的花粉块移出率和柱头花粉块沉降率, 在中华蜜蜂的传粉过程中, 芳香石豆兰铰链结构的唇瓣起着重要作用。人工授粉试验表明, 芳香石豆兰自交授粉不结实, 异交授粉结实率达90%以上, 芳香石豆兰为自交不亲和的繁育系统。芳香石豆兰具有较强的克隆生长能力, 同一个体花期内有大量的花同时开放, 其传粉者中华蜜蜂平均单次访花(4.29 ± 0.40)朵( n= 66), 造成了严重的同株异花传粉。芳香石豆兰附生于石灰岩山顶岩石或树干上, 种群密度较低, 使得不同个体之间花粉交流困难, 自交不亲和的特性导致了芳香石豆兰自然不结实。本研究结果为开展芳香石豆兰的有效保护提供了依据。     

石豆兰属(Bulbophyllum)(兰科)中两个种的新名称

本文发表石豆兰属Bulbophyllum（Orchidaceae）中两个种的新名称：Bulbophyllum maanshanense和Bulbophyllum xiajinchuangense以取代两个应废弃的晚出同名：Bulbophyllum malipoense Z.J.Liu,L.J.Chen＆W.H.Rao（2010）,non Z.J.Liu,S.C.Chen＆S.P.Lei（2008）和Bulbophyllum minus Z.J.Liu,L.J.Chen＆W.H.Rao（2010）＂minor＂,non（De Wild.）De Wild.（1921）。     

Lip anatomy and its implications for the pollination mechanisms of Bulbophyllum species (Orchidaceae)

BACKGROUND AND AIMS: The lip structure of six Brazilian and one Asiatic species of Bulbophyllum with wind-assisted fly pollination (B. involutum, B. ipanemense and B. weddellii) and non-wind-assisted fly pollination (B. epiphytum, B. glutinosum, B. regnellii and B. rothschildianum) was studied to investigate the presence of secretory tissues related to these pollination mechanisms. METHODS: The lip study was carried out through scanning electron microscopy (lip surface) and light microscopy (anatomical features). KEY RESULTS: In most of the species studied, the osmophores (odour glands) were located in the lobes and in the upper surface of the lip callus. Differences in the lip structure were observed between the two groups (the presence of a nectary and the extent of osmophore surface), depending on the mechanism of pollination. Nectaries were found in the cavity callus in B. ipanemense, B. involutum and B. weddellii, even though their pollinators were presumably attracted by the instinct to oviposit. CONCLUSIONS: These findings corroborate the hypothesis that, because pollination in these species is dependent on an unpredictable external factor (wind), nectar is necessary to keep the insect in the flower for a long period. Despite the occurrence of a liquid-like nectar in the flowers of B. epiphytum, B. glutinosum, B. regnelli and B. rothschildianum, no anatomical evidence for nectaries was found in the lips of these species, although a similar structure may occur in another region of the flowers. This observation agrees with the fact that pollination by lip movement in the latter species requires only gravity, with no additional mechanism being needed to keep the flies in the flower.     

中国兰科石豆兰属（Bulbophyllum）二新种

对兰科（Orchidaceae）石豆兰属（Bulbophyllum）二新种,副萼石豆兰（B.malipoense Z.J.Liu,L.J.Chen＆W.H.Rao）和小副萼石豆兰（B.minor Z.J.Liu,L.J.Chen＆W.H.Rao）作了描述和绘图。该二新种属于石豆兰属副萼组（Bulbophyllumsection BisetaJ.J.Verm.ex N.Pearce,P.J.Cribb＆J.Renz）,与该组的刺萼石豆兰（B.bisetum Lindl.）相似,区别在于两新种的叶片先端二裂和唇瓣无毛。小副萼石豆兰与副萼石豆兰的区别在于假鳞茎椭圆球形;叶片卵状椭圆形,长1.2～2 cm;侧副萼片较短,长约1 mm;中副萼片几乎与两侧萼片边缘合生。     

Bulbophyllum wuzhishanensis (Orchidaceae), a new species from Hainan, China

Bulbophyllum wuzhishanensis, a new species from Hainan, China, is described and illustrated. The new species is probably related toBulbophyllum ledungense, but differs from it by having a long inflorescence, a column without stelids, and a longer lip.     

中国石豆兰属新资料

报道了中国兰科（Orchidaceae）石豆兰属（Bulbophyllum）2个新记录种——拟环唇石豆兰（Bulbophyllum gyrochilum Seidenf.）、泰国卷瓣兰（Bulbophyllum thaiorum J. J. Smith）及中国大陆1新记录种,乌来卷瓣兰（Bulbophyllum macraei(Lindl.) Reichb. f.）,并提供描述及照片。     

中国兰科石豆兰属一新种

描述了中国石豆兰属Bulbophyllum一新种——天贵卷瓣兰（Bulbophyllum tianguii K．Y．Lang ＆ D．Luo）,并提供墨线图。该种产于广西乐业县,与富宁卷瓣兰B．funingense Z．H．Tsi＆S．C．Chen外貌颇相似,但中萼片先端渐尖并具3mm长的芒,侧萼片宽4～4．5mm,花瓣先端渐尖并具1．5mm长的芒,唇盘具2条肉质、具缘毛的纵脊,可与后者明显区别。     

Differential cell enlargement and its possible implication for resupination in Lemboglossum bictoniense (Orchidaceae)

Changes in the structural features of cell populations in the pedicel of Lemboglossum bictoniense (Bateman ex. Lindley) Halbinger were examined by means of light microscopy in relation to resupination, a twisting of the pedicel through 180^o prior to flower opening. Serial sections in transverse and longitudinal planes were taken from pre-resupinate and fully resupinate pedicels of flowers from a single inflorescence, and comparisons made between the tissues. The pedicel is a prismatic cylinder flattened on three sides, producing three distinct ribS. Each rib contains one central vascular bundle enclosed by cortical parenchyma. Intervening cortical parenchyma forms flanks external to a central core of three vascular bundles, each of which is split into three distinct traces at this level. Resupination is accompanied by axial and radial expansion of cortical parenchyma. Specialized raphide-bearing cells in the cortex expand axially doubling their length in the ground parenchyma. These raphide cells are localized in the rib cortex, and their expansion is reflected in greater elongation of the ribs relative to flank areas. The extra rib length is accommodated by a lateral displacement (twisting) of the ribs around the central axis of the pedicel. Tissue distortion is reduced by cell division, expansion of intercellular spaces and a radial contraction of pith parenchyma. Raphide cell elongation could be a contributing factor in pedicel twisting. The direction of resupination may be controlled by the organization of these cells into arcs on one or other side of the rib vascular bundle.     

Bulbophyllum huangshanense sp. nov. (Orchidaceae) from Anhui,China

Bulbophyllum huangshanense, a new species of orchid from Anhui, China, is described and illustrated. This new species is close to B. taeniophyllum with pseudo‐bulbs closely spaced along the rhizome, leathery leaf, entire dorsal sepal, toothed petals, the lateral edges of lateral sepals connate and fleshy lip, but differs from the latter in having roots arising from the node with the pseudo‐bulb, inflorescence much shorter than leaf, flowers pure yellow, lip mobile, and stelidia broadly triangular.     

A remarkable new Bulbophyllum, sect. Sestochilus (Orchidaceae) from Thailand

Ongoing studies show that what hitherto in Thailand and neighboring countries have been gathered under one variable species, Bulbophyllum lobbii , must be separated in a number of distinct, well defined species. One such. B. smitinandii , is treated here.     

Chloroplast genomic diversity in Bulbophyllum section Macrocaulia (Orchidaceae,Epidendroideae, Malaxideae): Insights into species divergence and adaptive evolution

Bulbophyllum is the largest genus in Orchidaceae with a pantropical distribution. Due to highly significant diversifications, it is considered to be one of the most taxonomically and phylogenetically complex taxa. The diversification pattern and evolutionary adaptation of chloroplast genomes are poorly understood in this species-rich genus, and suitable molecular markers are necessary for species determination and phylogenetic analysis. A natural Asian section Macrocaulia was selected to estimate the interspecific divergence of chloroplast genomes in this study. Here, we sequenced the complete chloroplast genome of four Bulbophyllum species, including three species from section Macrocaulia. The four chloroplast genomes had a typical quadripartite structure with a genome size ranged from 156,182 to 158,524 bp. The chloroplast genomes included 113 unique genes encoding 79 proteins, 30 tRNAs and 4 rRNAs. Comparison of the four chloroplast genomes showed that the three species from section Macrocaulia had similar structure and gene contents, and shared a number of indels, which mainly contribute to its monophyly. In addition, interspecific divergence level was also great. Several exclusive indels and polymorphism SSR loci might be used for taxonomical identification and determining interspecific polymorphisms. A total of 20 intergenic regions and three coding genes of the most variable hotspot regions were proposed as candidate effective molecular markers for future phylogenetic relationships at different taxonomical levels and species divergence in Bulbophyllum. All of chloroplast genes in four Bulbophyllum species were under purifying selection, while 13 sites within six genes exhibited site-specific selection. A whole chloroplast genome phylogenetic analysis based on Maximum Likelihood, Bayesian and Parsimony methods all supported the monophyly of section Macrocaulia and the genus of Bulbophyllum. Our findings provide valuable molecular markers to use in accurately identifying species, clarifying taxonomy, and resolving the phylogeny and evolution of the genus Bulbophyllum. The molecular markers developed in this study will also contribute to further research of conservation of Bulbophyllum species.     

The correct name for Bulbophyllum uniflorum Griff., nom. illeg. (Orchidaceae)

An attempt is made to find the correct name for Bulbophyllum uniflorum Griff., nom. illeg., and as valid name Bulbophyllum monanthum (Kze.) J. J. Smith is proposed.     

Diverse labellar secretions in African Bulbophyllum (Orchidaceae: Bulbophyllinae) sections Ptiloglossum,Oreonastes and Megaclinium

Floral food‐rewards of Bulbophyllum range from nectar to protein‐rich mucilage and lipid‐rich labellar secretions. For the first time, the structure of the labellum and the secretory process are investigated for four African Bulbophyllum species. The most specialized type of labellar organization occurred in B. schinzianum, the deep, narrow, median longitudinal groove consisting of palisade‐like secretory cells flanked by trichomes containing lipid droplets, and the copious secretion containing sugar. This groove was absent or poorly defined, shallow and wide, in the remaining taxa, the scant secretion containing lipid. All taxa possessed a striate cuticle lacking cracks and pores, and micro‐channels were present, cuticular blisters occurring only in B. schinzianum. The labellum contained storage parenchyma (B. lupulinum) or mesophyll‐like parenchyma (B. schinzianum), but in section Megaclinium (B. falcatum and B. maximum), these were replaced by aerenchyma. In B. schinzianum, the form of the labellar groove, sweet fragrance and sugary secretion suggest pollination by Hymenoptera, the food‐reward and fragrance indicating that pseudocopulation is unlikely. Conversely, the form of the labellum of taxa having smaller flowers, and the lipid‐rich secretion, suggests pollination by small flies. The labellar aerenchyma may facilitate this process or even aid wind‐assisted pollination. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 266–287.     

Recurrent polymorphic mating type variation in Madagascan Bulbophyllum species (Orchidaceae) exemplifies a high incidence of auto‐pollination in tropical orchids

The transition from outcrossing to self‐fertilization is one of the most common evolutionary changes in angiosperms. The orchid family exemplifies this evolutionary trend but, because of a general lack of large‐scale surveys on auto‐pollination in orchid taxa, the incidence and modes of auto‐pollination among (sub)tropical orchids remain poorly known. In the present study, we assessed the frequency and mode of auto‐pollination within and among species of a largely monophyletic group of Madagascan Bulbophyllum. The capacity for autonomous fruit set was investigated by bagging experiments in the greenhouse and the field, complemented with detailed floral micromorphological studies of the gynostemium. Our survey comprises 393 accessions, representing at least 78 species, and thus approximately 37% of the species diversity of the genus in the Madagascan region. Our studies revealed that mating type is directly related to gynostemium structure, most often involving the presence or absence of a physical barrier termed ‘rostellum’. As a novel and unexpected finding, we identified eight species of a single lineage of Madagascan Bulbophyllum (termed ‘clade C’), in which auto‐pollinating morphs (selfers), either lacking a rostellum or (rarely) possessing a stigmatic rostellum, co‐exist with their pollinator‐dependent conspecifics (outcrossers). We hypothesize that auto‐pollination via rostellum abortion has a simple genetic basis, and probably evolved rapidly and recurrently by subtle changes in the timing of rostellum development (heterochrony). Thus, species of clade C may have an intrinsic genetic and developmental lability toward auto‐pollination, allowing rapid evolutionary response under environmental, perhaps human‐disturbed conditions favouring reproductive assurance. Overall, these findings should stimulate further research on the incidence, evolution, and maintenance of mating type variation in tropical orchids, as well as how they adapt(ed) to changing environmental conditions. © 2014 The Authors. Botanical Journal of the Linnean Society published by John Wiley & Sons Ltd on behalf of The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 242–258.     

The gynostemium of Bulbophyllum ecornutum (J. J. Smith) J. J. Smith (Orchidaceae)

RASMUSSEN, F. N., 1985. The gynostemium of Bulbophyllum ecornutum (J. J. Smith) J.J. Smith (Orchidaceae) . Stages in the development of the gynostemium of Bulbophyllum ecornutum demonstrate that the pollinium stalk is a hamulus in this and in a closely related species, B. gibbolabium . A hamulus arises by apical growth and reflexion of the median carpel. Hamuli have recently been discovered in several orchid genera, and a transverse fold of the rostellar apex is already known from a large group of orchids. The closely related B. cornutum has a quite different gynostemium structure.     

中国兰科二新记录种

兰科植物资源调查是掌握地区兰科本底资料的基础,对研究兰科植物的地理分布和资源多样性具有重要意义.该文报道了分别产自中国西藏自治区墨脱县和巴宜区的石豆兰属(Bulbophyllum Thou.)中国分布新记录种——尼泊尔大苞兰(B.raskotii J.J.Verm.,Schuit.&de Vogel)和曲唇兰属[Pan...     

Temporal variation in pollinarium size after its removal in species of Bulbophyllum: A different mechanism preventing self-pollination in Orchidaceae

InBulbophyllum involutum andB. ipanemense (Orchidaceae), two closely related species, shortly after removal the pollinarium has a diameter of approximately twice that of the entrance of the stigmatic cavity, requiring a mean time of 105 to 135 minutes to shrink in width and allow pollination. Because the pollinators of these species remain for some minutes in the same flower after removing the pollinia this mechanism, previously unknown inOrchidaceae, may be very important in preventing self-pollination. This mechanism does not occur inB. weddellii, and the pollinator does not remain in the flower after removing the pollinia. The smaller diameter of the stigmatic cavity inB. involutum reduces by 50% the chances of interspecific pollination withB. weddellii, and interspecific crossing is strictly unidirectional. This is important in maintaining isolation between these sympatric species, which share the same pollinators and have synchronized flowering.