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1.
The compositions of leaf monoterpenoids from 11 species in the Juniperus section (Juniperus chinensis var. chinensis,J. virginiana, J. communis var. montana,J. rigida, J. chinensis var. globosa,J. chinensis var. sargentii,J. chinensis ‘Kaizuka Variegata’,J. squamata ‘Wilsonii’,J. x media ‘Shimpake’,J. x media ‘Plamosa Aurea’, andJ. squamata ‘Aloderi’) were comparatively analyzed by GC-MS. Of the 24 compounds identified, α-pinene, myrcene, limonene, terpinolene, and bornyl acetate were common to all, but particular combinations differed remarkably among taxa. The simplest composition (eight compounds) was found in.J, chinensis var. chinensis; the most complex (19 compounds), inJ. x media ‘Shimpake’. Cluster analysis generated four distinctive clades within the Juniperus section. The minimum spanning network revealed thatJ. squamata ‘Wilsonii’ andJ. x media ‘Shimpake’ were most similar in their chemical makeup.  相似文献   

2.
采用样方法对桃源洞国家级自然保护区的牛石坪南方铁杉(Tsuga chinensis)群落和梨树洲南方铁杉群落进行调查,分析群落种类组成和结构特征;采用Shannon-Weiner指数、Simpson指数和Pielou均匀度指数研究群落各层的物种多样性;依据径级频率分布分析2个南方铁杉群落中南方铁杉种群的年龄结构和更新状况。结果表明:(1)桃源洞的2个南方铁杉群落中常绿植物占优势,群落有一定的季相变化,夏季呈暗绿色,秋冬淡黄绿色。(2)牛石坪南方铁杉群落共有维管植物13科21属26种,梨树洲南方铁杉群落共有维管植物22科30属36种;地理成分分析表明温带成分明显高于热带成分,表现为亚热带山地性质。(3)群落垂直结构可分为乔木层(进一步分为乔木上层、乔木中层、乔木下层3个亚层)、灌木层和草本层。(4)2个群落的Shannon-Wiener指数和Simpson指数均为乔木下层乔木中层灌木层乔木上层,Pielou均匀度指数为乔木中层和乔木下层乔木上层和灌木层。(5)牛石坪南方铁杉群落的优势种群为马银花(Rhododendron ovatum)、南方铁杉、尖连蕊茶(Camellia cuspidata)和鹿角杜鹃(Rhododendron latoucheae),梨树洲南方铁杉群落的优势种群为银木荷(Schima argentea)、南方铁杉、鹿角杜鹃和背绒杜鹃(Rhododendron hypoblematosum)。(6)根据年龄结构和生存分析,牛石坪的南方铁杉种群为衰退型,低龄级个体和种群数量都严重不足,难以实现自然更新;梨树洲的南方铁杉种群为增长型,低龄级个体数较丰富,年龄结构分布基本连续,惟其群落郁闭度较高,自我更新还存在一定的挑战。根据以上结果建议对牛石坪的南方铁杉群落进行就地保护和适当人为干扰,对梨树洲群落加强后续监测工作。  相似文献   

3.
Cocoicola livistonicola, a new species from senescent petioles ofLivistona chinensis in Hong Kong, is described. It differs from previously reportedCocoicola species in having differently shaped ascospores. Notes onCocoicola cylindrospora which was recently collected onCocos nucifera in the Seychelles are also provided.  相似文献   

4.
朱道弘  张超  谭荣鹤 《生态学报》2011,31(15):4365-4371
中华稻蝗Oxya chinensis为重要的水稻害虫,在我国除青海、西藏、新疆、内蒙古等未见报道外,南起海南北至东北均有分布,在许多的分布区域1年发生1代。为探索中华稻蝗长沙种群的生活史及其季节适应特征,通过野外和实验室的研究,调查了其发生代数、孵化率和卵滞育率的季节变化及越冬卵的存活率。结果显示,中华稻蝗长沙种群为1年2代和1年1代混合发生:第1代卵产卵后大部分孵化为若虫而1年完成2代,但亦有19.4% -4.1%的卵不孵化而1年只能完成1世代。第1代成虫于6月上旬至8月上旬羽化,6月下旬至8月中旬产卵;第2代若虫于7月初开始孵化,9-10月羽化为成虫,10月上旬至11月下旬产卵。在室外自然条件下,中华稻蝗长沙种群6-8月(第1代)和10-11月(第2代)所产卵块均为部分滞育,滞育率为30%左右,皆无显著差异。然而,其卵滞育率在12月以后显著降低,仅为6.6%或以下,卵滞育快速地得以解除。因此,包括非滞育卵和滞育解除卵,中华稻蝗长沙种群的越冬卵皆以非滞育状态度过其后的寒冷季节。即使是遭遇长江流域2007年末至 2008年初异常寒冷的冬季,在长沙地区越冬后其卵的存活率亦在98%以上。非滞育状态的中华稻蝗长沙种群越冬卵完全能安全地越冬,其滞育的发生并非是为了提高其耐寒性而安全度过不适环境。并探讨了中华稻蝗长沙种群卵滞育的进化意义。  相似文献   

5.
Ophiocaryon barnebyanum from the Serra da Neblina (Venezuelan-Brazilian border) andO. neillii from southern Ecuador are described and illustrated, and their morphological relationships with allied spcies are discussed.Ophiocaryon barnebyanum is morphologically similar toO. duckei, but it differs by its larger leaves, leaflets, petioles, petiolules, and inflorescences, the higher number of secondary veins, and the ciliate sepals.Ophiocaryon neillii is a small tree related toO. klugii but differs by its smaller leaflets, petiolules and inflorescences, fewer secondary veins, lanceolate-acuminate sepals, and orbicular staminodes. An updated key to the species ofOphiocaryon is provided.  相似文献   

6.
报道了中国兰科植物一新记录种:高褶石仙桃[Pholidota advena(Par. & Rchb. f.) Hook. f.],并提供了描述与图片。该种与石仙桃(P. chinensis Lindl.)相似,但下唇具3~5个明显隆起的片状脊以及上唇有3个波浪状龙骨一直向顶端延伸汇合。  相似文献   

7.
8.
很多入侵植物具有克隆性,克隆整合对入侵克隆植物生长和繁殖具有重要的贡献。自然界中,植物生长和繁殖所需的各种资源如光照、水分和矿质养分等在空间上分布通常是异质的,但关于异质环境下克隆整合对入侵植物和本土同属植物种间关系影响的研究相对缺乏。通过温室控制实验,将入侵植物南美蟛蜞菊(Wedelia trilobata)和同属本土植物蟛蜞菊(W.chinensis)的分株对单独种植或者混合种植在异质性光照条件下,同时通过保持或者切断分株之间的连接来控制克隆整合效应的有无,研究异质光照环境下克隆整合对南美蟛蜞菊和蟛蜞菊种间关系的影响。克隆整合对南美蟛蜞菊和蟛蜞菊的生长和繁殖都有促进作用,且南美蟛蜞菊比蟛蜞菊从克隆整合中获益更多。与单独种植相比,两者混种对南美蟛蜞菊的叶生物量有显著影响,而对本地种蟛蜞菊的根生物量有显著影响。克隆整合和种间关系对南美蟛蜞菊的总生物量和叶生物量产生了显著的交互作用,而对蟛蜞菊各指标无显著影响。克隆整合状态显著影响了南美蟛蜞菊和蟛蜞菊的种间关系。这些结果表明,异质环境下克隆整合可以改变入侵植物南美蟛蜞菊和本土植物蟛蜞菊的生长性状及种间关系。  相似文献   

9.
Summary Seventeen cultivars belonging to the genus Dianthus were examined for protoplast isolation, culture and shoot regeneration under the same conditions. These included D. caryophyllus, D. chinensis, D. barbatus, D. plumarius, D. superbus and D. japonicus as well as interspecific hybrid cultivars (D. caryophyllus x D. chinensis and D. chinensis x D. barbatus). In all cultivars, viable protoplasts were isolated at high yields from leaves of axenic shoot cultures and some of these protoplasts divided and formed colonies. However, shoot regeneration frequencies were markedly different among the species. High frequency shoot regeneration was obtained from D. chinensis and interspecific hybrid cultivars, while only low frequency or no shoot regeneration was obtained from other species.Abbreviations MS Murashige and Skoog (1962) - FW fresh weight - MES 2-N-morpholinoethane sulfonic acid - FDA fluoroscein diacetate - NAA 1-naphthaleneacetic acid  相似文献   

10.
群落演替对夏蜡梅种群分布和数量的影响   总被引:1,自引:0,他引:1  
对夏蜡梅(Sinocalycanthus chinensis(Cheng et S.Y.Chang)Cheng et S.Y.Chang)所有分布地(浙江临安、天台和安徽绩溪)进行了详细调查,分析夏蜡梅种群面积、密度、结构和群落特征等,并与前人调查结果对比,阐明群落演替对夏蜡梅种群的影响。10余年来,由于国家相关政策的实施(退耕还林、天然林保护以及自然保护区的建立等)以及夏蜡梅分布地林地经营模式的改变,不同夏蜡梅群落呈现发展演替的不同状态,从而对夏蜡梅种群产生了显著影响。从群落类型来看,较为稳定的种群为大明山、西坑、白水坞、捣臼孔种群,种群结构为增长型或稳定型,群落处于乔木或顶级乔木阶段,原生植被保存较好,生境相对稳定,各物种在长期竞争中趋于稳定;直源种群为严重衰退的种群,群落经历了从灌丛阶段向灌乔阶段演化,原来同层次的常绿乔木逐渐形成密集的乔木层,郁闭度高,造成夏蜡梅生长不良甚至死亡,幼苗缺少或数量少,更新困难,此区域的夏蜡梅呈逐渐退化消亡趋势;而溪古坪、龙塘山种群所处群落正是属于这种群落演替的早期阶段,处于衰退过程中种群,不加人工干预也会逐渐退化;而双石边、经过坪等种群虽目前数量多,分布集中,更新良好,但变数最大,一旦人工干扰加剧或消除,则种群结构将快速发生变化,走向消亡的几率极大。该研究结果可为夏蜡梅保护提供科学依据。  相似文献   

11.
《Phytomedicine》2015,22(5):573-578
BackgroundTaxus chinensis (Pilger) Rehd is widely distributed in China and the northern hemisphere, and the most popular medicinal component isolated from Taxus chinensis is paclitaxel (PTX), which has now become the first-line chemotherapeutic drug for breast cancer and ovarian cancer. Oral administration of pure PTX as a potential anti-cancer agent is compromised by low bioavailability.Hypothesis/purposeIn the clinical practice of traditional Chinese medicine, drug co-administration in the form of mixtures or formula could achieve pharmacokinetic/pharmacodynamic synergies. In this study, we aimed to investigate whether there exist any ‘inherent’ phytochemical synergy from Taxus chinensis extract that could improve PTX bioavailability.Study designPharmacokinetic study of PTX after oral administration of Taxus chinensis extracts or single PTX was performed. In addition, comparative cytotoxic studies were carried out on the MCF-7 breast cancer cell lines.MethodsThe plasma concentrations of PTX were determined using a validated high performance chromatography tandem mass spectrometry method. The cytotoxicity was compared using the MTT assay.ResultsOral administration of taxane fractions isolated from Taxus chinensis (containing 17.2% PTX) could achieve remarkably higher blood concentration and systemic exposure of PTX in rats, while the retention of PTX was significantly improved. Further tissue distribution analysis revealed that the penetration of PTX into major tissues was drastically increased compared with that of single PTX. In addition, in MCF-7 cells, the co-existing components in taxane mixtures could strengthen the inhibitory effects of PTX on tumor cell proliferation.ConclusionTogether, these results support that administration of PTX in the form of taxane mixtures may become a novel approach to improve the poor bioavailability of PTX. Moreover, the inherent synergy from Taxus chinensis taxane extracts promises a novel strategy to strengthen PTX efficacy.  相似文献   

12.
Summary A new trichostrongylid nematode, Obeliscoides pentalagi n. sp., from the stomach of the Ryukyu Rabbit, Pentalagus furnessi, collected on Amami-ohshima Island, south Japan is described. O. pentalagi n. sp. resembles O. leporis Schulz, 1931 and O. travassosi Liu & Wu, 1941, but differs in the relative size and morphology of the dorsal ray and genital cone of the males. The number and distribution of longitudinal cuticular ridges of O. pentalagi n. sp. is similar to those of O. cuniculi multistriatus Measures & Anderson, 1983, but it differs in the morphology of the spicules, dorsal ray and genital cone in males, and in the morphology of the prevulval lobe of the females. The discovery of O. pentalagi further supports the hypothesis of a Eurasian origin of the genus Obeliscoides (Graybill, 1923) Graybill, 1924 (Durette-Desset, 1983; Durette-Desset & Chabaud, 1977; Measures & Anderson, 1983a, b, c, 1984). The number and distribution of longitudinal cuticular ridges and variation of the prevulval lobe in females of O. leporis Schulz, 1931 are also examined and compared with those of other species.  相似文献   

13.
Hypotheses for the origins of tetraploids and hybrids ofSphenomeris chinensis sensu lato in Japan were tested using electrophoretic analysis of isozymes. Comparison of banding patterns supported the hypothesis that plants having abortive spores had resulted following hybridization between diploidS. chinensis var.chinensis andS. biflora and between diploid var.chinensis andS. gracilis. Results from isozymic analyses also revealed thatS. intermedia probably originated through allotetraploid speciation following hybridization between var.chinensis andS. biflora. There were two electrophoretic variants among tetraploids ofS. chinensis. One variant, restricted to the southern Ryukyu Islands, is probably an allotetraploid of hybrid origin between diploidS. chinensis andS. gracilis. It has been described as a new species,S. yaeyamensis Lin, Kato & K. Iwatsuki. The other variant, morphologically corresponding to var.chinensis, is distributed at least throughout southern Japan and also in northern Thailand. Its origin is uncertain, but one of the parents is probably diploidS. chinensis. Sphenomeris intermedia andS. yaeyamensis occur inland, whereas the parentalS. biflora andS. gracilis are halophilous and rheophllous, respectively.  相似文献   

14.
A new Thalassomonhystera species, i.e. T. traesti n.sp., and a new subspecies, Monhystrella lepidura chinensis n. subsp., together with Eumonhystera andrassyi (Biró, 1969) Andrássy, 1981, Monhystrella macrura (de Man, 1880) Andrássy, 1981 and Monhystrella iranica Schiemer, 1965 are described from Li River at Guiling, China. Thalassomonhystera traesti n.sp. is characterised by a combination of the following characters: expanded lip region, large and anteriorly situated amphids, prominent inner labial sensilla, and slender spicules and tube-like gubernaculum in males. Monhystrella lepidura chinensis n. subsp. belongs to Monhystrella lepidura (Andrássy, 1963) Andrássy, 1968 but differs from the three hitherto described subspecies in its possession of a pharynx that posteriorly expands into a double bulb. Monhystrella macrura, M. iranica and Eumonhystera andrassyiare reported here for the first time from China.  相似文献   

15.
Eight new South American species ofPalicourea are described and illustrated:P. crystallina from north-central Peru differs fromP. loxensis from Ecuador, also described herein, by its longer calyx limbs, 1.2–2.5 mm long, with the lobes often unequal in length;P. cutucuana from southern Ecuador differs fromP. angustifolia in its broader leaves and inflorescences and larger corollas;P. gelsemiiflora of northern Peru is distinguished by its pedicels 11–20 mm long, calyx limbs 7–11 mm long, relatively large yellow corollas with tubes 32–33 mm long, relatively large fruits 12–13 mm long, and pyrenes with an unusual spongy wall;P. gemmiflora of southern Ecuador and northern Peru differs fromP. subtomentosa by its longer corollas with horn-like projections on the abaxial surfaces of the lobes;P. lemoniana of southwestern Venezuela differs fromP. nitidella by its corolla tubes 17–18 mm long with the lobes pubescent abaxially and fromP. grandiflora by its secondary leaf veins only 7–10 pairs and corollas externally with lanose trichomes to 0.5 mm long;P. loxensis of southern Ecuador differs fromP. garciae by its densely reticulated secondary and tertiary leaf venation, membranaceous stipules, and sessile rather than pedicellate flowers;P. otongaensis of north-central Ecuador differs fromP. holmgrenii by its longer corollas with well developed horn-like appendages borne on the abaxial surfaces of the lobes; andP. smithiana of central Peru differs fromP. lobbii by its laminar stipules with obtuse to rounded lobes only 0.5–1 mm long, yellow corollas, and pyrenes that are ridged dorsally.  相似文献   

16.
Tilia chinensis Maxim. is widespread and locally frequent in the mountains of south‐western China, mainly in Yunnan and Sichuan. It occurs in mixed evergreen‐deciduous, broad‐leaved forests and extends up to over 3000 m in coniferous forests and birch woodland. The species is very distinct and easily recognised by its normally orbicular, serrate leaves, sessile or shortly stalked, oblong bracts, cyme with only three flowers and large ellipsoidal fruits with longitudinal ribs, especially prominent when dry. Evidence is summarised for including T. intonsa Wilson, T. laetivirens Rehd. & Wilson and T. yunnanensis Hu within T. chinensis. Until recently T. chinensis was rare in cultivation in the British Isles and confined to botanic gardens and arboreta. Young trees grow slowly but leaf‐out late and usually avoid damage from spring frosts; they grow well on moist but freely draining, moderately fertile soils in the shelter of glades.  相似文献   

17.
We show vicariance of Cicindela chinensis in Okinawa, Japan (differentiated within Japan) and Korea–China through construction of Bayesian inference trees by BEAST2. Calibration was done using an assumption of the MRCA expansion of C. chinensis at 1.55 Ma (=geologically obtained formative time of the Ryukyu islands) following the protocol of BEAUti. We derived substitution rates for mitochondrial COI (1.66%/m.y.) and nuclear 28SrRNA (0.109%/m.y.) of analyzed Cicindela. Cicindela ferriei is a sister of C. chinensis, and these two species differentiated from each other at ca. 3 Ma before the expansion of C. chinensis. However, they are not strongly differentiated between Amami‐Oshima and Tokuno‐shima, although they display different color. Vicariance at 1.55 Ma is also recognized between Cicindela batesi in Taiwan and Cicindela aurulenta and virgula in continental China. From the sequence data we obtained, it is also evident that C. c. okinawana recently colonized Ishigaki‐jima from Okinawa‐jima, as did C. batesi in Iriomote‐jima from Taiwan.  相似文献   

18.
19.
Species composition and photosynthetic characteristics of dominant species of ungrazed plot (UG), overgrazed plot (OG), and restored grazed plot (RG) were determined in the Xilin River Basin, Inner Mongolia, China. Both heavily grazing and restoration significantly affected the composition of different species and life forms. Leymus chinensis, Stipa grandis, and Cleistogenes polyphylla, three dominant perennial grasses in UG plot, contributed 58.9 % aboveground biomass to that of whole community, and showed higher net photosynthetic rate (P N), transpiration rate (E), and intrinsic water-use efficiency (WUE). In OG plot, relative biomass of L. chinensis and S. grandis significantly decreased, while relative biomass of three shrubs/sub-shrubs, Caragana microphylla, Artemisia frigida, and Kochia prostrata, obviously increased. Heavy grazing significantly decreased P N, E, and WUE of L. chinensis and S. grandis, while shrubs/sub-shrubs showed significantly higher photosynthetic activity and WUE than the grasses. After 18-year restoration, photosynthetic activities of L. chinensis and S. grandis were significantly higher than those in the OG plot. The proportion of L. chinensis, S. grandis, and C. microphylla significantly increased, and relative biomass of C. polyphylla, A. frigida, and K. prostrata markedly declined in RG plot. We found close relationships between physiological properties of species and their competitive advantage in different land use types. Higher photosynthetic capability means more contribution to total biomass. The variations in physiological characteristics of plants could partly explain the changes in species composition during degrading and restoring processes of Inner Mongolia typical steppes.  相似文献   

20.
《Journal of bryology》2013,35(3):153-155
Abstract

The taxonomy of Anomobryum julaceum and allied species with axillary bulbils in Europe and Asia is reviewed. A. concinnatum is regarded as a distinct species, occurring in W. and C. Europe, SW., N. and C. Asia and N. America. A. bavaricum has often been confused with A. concinnatum, but differs in its more numerous, small, reddish bulbils and in leaf shape; it is known only from the European Alps. The Asian A. nitidum also has numerous small reddish bulbils but it differs from A. bavaricum in leaf shape and bulbil form. A lectotype is designated for A. nitidum, of which A. gemmigerum and other nominal taxa are regarded as synonyms. Information is presented on geographical ranges and habitats of the four valid species.  相似文献   

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