新疆天山南坡中段种子植物区系垂直分布格局分析

对植物多样性垂直分布格局及其维持机制的研究可以有效揭示植物物种多样性分布特征及其环境影响因子。本文通过野外调查、查阅标本并结合相关文献资料,对天山南坡中段种子植物区系沿海拔梯度的分布格局进行了系统研究。结果显示,在大区域尺度上,科属种的物种丰富度随海拔升高均呈先增加后减少的趋势,且最高值出现在中低海拔1900~2000 m处;不同生活型植物沿海拔梯度的变化格局有所不同,其中,乔木、一年生草本、藤本及寄生植物表现出随海拔升高物种丰富度逐渐降低的趋势,灌木、多年生草本及二年生草本植物物种丰富度则呈先增加后减少的变化趋势;从植物区系地理成分来看,世界分布所占的比重沿海拔梯度升高呈先增加后减少的趋势;温带地理成分所占的比重沿海拔梯度升高呈缓慢上升趋势;古地中海地理成分所占的比重沿海拔梯度升高呈先增加后减少然后再增加的变化趋势;热带地理成分所占的比重沿海拔升高呈逐渐下降的趋势;东亚地理成分所占的比重沿海拔梯度升高呈先增加后减少然后再增加的变化趋势。对该分布格局与当地干旱的气候条件及海拔梯度上热量和水分条件的变化相适应。     

Nothia ex gr. excelsa (Grzybowski, 1898), ‘flysch-type’ agglutinated foraminifera from the Karpatian (Early-Miocene) of Hungary

Abstract

Nothia ex gr. excelsa (Grzybowski, 1898) branched, agglutinated, tubular foraminifera is documented for the first time from the Karpatian (latest Burdigalian) molasse sediments of the Paratethys. Excellently preserved specimens allowed the study of the macro- and microstructure of the test using reflected and polarized light microscopes, SEM and Raman spectroscopy. The mineralogical components of the agglutinated grains, the appearance of the protruded aperture with a scalloped-edge, the microstructure of the bilamellar wall, the presence of the calcite microgranular cement could all be described in detail. Based on autecology, the test morphology and the associated fauna indicate that Nothia ex gr. excelsa was a surface-dwelling detritivore with a seasonal-phytophagous mode of life.     

黄芪A6组分对流感病毒感染小鼠的防治作用

用黄芪生药1250～5000mg／kg,连续给药小鼠5d,其A6组分对100LD50或100ID50感染的BALB／C小鼠都有明显的预防和治疗作用,可降低感染幼鼠的死亡率和延长其平均存活天数;降低感染成年鼠的肺湿重。经X2和t检验,有显著性差异。且预防效果优于治疗。早期给药疗效较好。     

3种桉树组培苗不定根发生发育过程的解剖学观察

以巨尾桉‘GL9’、尾巨桉‘DH32-29’和尾边桉‘XF35’3种桉树无性系组培生根苗为材料,采用常规石蜡切片技术,对石蜡切片制作过程中的固定环节进行了优化,观察了桉树不定根的发育过程。结果表明:(1)采用FAA固定液固定材料,可获得染色清晰,组织完整的桉树根系切片。(2)‘GL9’和‘DH32-29’在生根诱导8d后生出不定根,生根类型为皮部生根;‘XF35’在生根诱导12d后生出不定根,生根类型为愈伤组织生根;‘GL9’不定根的根尖和根基处均有细胞旺盛分裂,‘DH32-29’不定根只在根尖有细胞旺盛分裂,‘XF35’不定根则只在其根基处有大量旺盛分裂的细胞。     

A New Algal Fossil from Early Cambrian in Qingzhen County,Guizhou Province,China

A new algal fossil was collected from the lower part of the Lower Cambrian, a Sinian-Cambrian boundary section in Abazhai of Qingzhen County, Guizhou Province. It was discovered in petrographic thin sections of a black laminated chert. The new fossil, Symphysosphaera radialis gen. et sp. nov. is a fossilized muhicellular colony characterized by a surface layer of cells enclosed in an envelope, inner cavity permeated with dark dense mucilage embedded with numerous spherical units. Its difference from all morphs discovered in Precambrian, indicates that the genus may represent member of a new order at the beginning of Cambrian. hs stratigraphic and biological significance merits our attantion.     

三蕊草属Sinochasea Keng系统位置的研究

叶片表皮、叶片横切面、花粉和淀粉粒的微观特征,对青藏高原的特有类群三蕊草属Sinochasea Keng的系统位置进行了探讨。结果表明,三蕊草S.trigyna Keng在上述微观性状上与毛蕊草Duthiea brachypodia(P.Candargy) Keng et Keng f.差距最小,与冠毛草Stephanachne pappophorea(Hack.)Keng差距次之,与宝兴野青茅Deyeuxia moupinensis(Franch.) Pilger和拂子茅Calamagrostis epigeios(L.) Roth差距最大;三蕊草属的系统位置应处于毛蕊草所隶的燕麦族Aveneae中;在系统演化上,燕麦族是最原始的类群,它可能直接或间接地派生了针茅族Stipeae和剪股颖族Agrostideae。     

Notes on the Genus Sonneratia (Sonneratiaceae) in S. E. Asia

Sonneratia, a small genus of Sonneratiaceae, is widely distributed throughout SE. Asia, E. Africa and N. Australia, extending from 18˚S. to 20˚N. and from 45˚ to 150˚E. In China it occurs only in the Hainan Island. In this paper, two new sections areproposed and six species are recognized, of which one is described as new.     

Leaf Anatomy of Fourteen Species in Carex Subgenus Indocarex (Cyperaceae)

Among the subgenera of the genus Carex, the subgenus Indocarex has been seldom studied in any respects, Its systematic position and its subdivision are still disputable. Leaf anatomy of 14 species in the subgenus lndocarex from China was studied. The anatomical characters are proved to be systematically valuable. (1) Characters of lamina transverse section: All leaves of these 14 species are dorsiventral. The outline mostly V-shaped, occasionally flat or nearly flat, with adaxial lateral rib in each half of lamina and some of them flanged. The cells of adaxial surface larger than those of abaxial surface, and the epidermal cells over veins usually smaller than others. Air-cavities between vascular bundles are well developed, and bulliform cells also well developed in most taxa. The vascular bundles are collaterai, bundle sheaths double-layered, and the outer sheath parenchymatous and the inner sheath fibrous. (2) Characters of lamina epidermis: The shape of the cell on both surfaces is generally rectangular, and the anticlinal wall of epidermal cell sinuous; stomata is paracytic, elliptic to oblong, rarely sub-circular; prickles occur on adaxial surfaces of certain species; papillae are only obvious on abaxial surface of C. moupinensis Franch. The characters of transverse section and epidermis of leaf blades of these 14 species differ from each other to certain degree, and closely related species are similar in anatomical characters. The anatomical characters of lamina are of value for classification at specific and sectional level of the subgenus Indocarex. Despite of the variation of these characters among species, a certain num ber of characters appears to be shared by the members of the subgenus, and some of the common characters are primitive. In addition, some gross morphological characters are common and primitive also. Therefore, the subgenus Indocarex may be primitive in the genus Carex. The anatomical and morphological characters of C. scaposa C. B. Clakre and C. densifimbriata Tang et Wang ex S. Y. Liang are distinct. The two species and their allies should be treated as section instead of subsection. The three species in the sectionPolystachyae share some anatomical characters and comprise a coherent group.