中国早熟禾属植物部分种叶下表皮微形态的研究

通过光学显微镜及扫描电子显微镜对中国早熟禾属20种、6亚种及2变种植物的叶下表皮微形态特征进行了观察, 以明确叶表皮微形态特征在早熟禾属植物中的分类学意义。结果显示：(1)早熟禾属植物的叶下表皮长细胞多为长筒状或纺锤形,少数短筒状,细胞壁波状弯曲或近平直;脉间具有短细胞或缺如;气孔器多数常见,副卫细胞平行形至低圆屋顶形;脉上具有刺细胞或缺如,脉间刺细胞多为缺如;脉上硅细胞单生或对生,椭圆形、肾形、新月形、近方形、长方形边缘波状弯曲或结节形;部分早熟禾属植物叶下表皮存在冠细胞。(2)早熟禾属植物叶下表皮微形态特征在长细胞的形状及其细胞壁的弯曲与否、短细胞的有无及其形状、气孔器的分布与副卫细胞的形状、刺细胞的分布、脉上硅细胞的形状、冠细胞的有无这些方面存在着一定的差异,可为该属植物种间分类提供参考依据。叶表皮微形态证据支持高原早熟禾、细叶早熟禾作为草地早熟禾亚种的处理意见。     

中国看麦娘属植物叶表皮微形态研究

看麦娘属是禾本科早熟禾亚科的重要类群,中国分布有8种。该研究采用光学显微镜和电子扫描电镜,对中国看麦娘属7种植物的叶下表皮(含叶鞘下表皮)微形态特征进行观察并探讨其分类学意义。结果表明：(1)看麦娘属叶鞘下表皮长细胞的形状呈长筒状或短筒状,深波状弯曲的细胞壁,脉间短细胞密布,单生或对生,形状多为新月形或椭圆形,脉区硅细胞为椭圆形,平行形或低圆屋顶形的气孔器,看麦娘属叶鞘下表皮特征高度一致,分类价值不大。(2)看麦娘属植物叶下表皮和叶鞘下表皮的显微结构存在很大不同,看麦娘属植物叶下表皮长细胞多为长筒状或短筒状或长菱形,平周壁平直或不明显弯曲,脉间区短细胞分布或无,脉区刺毛密布,脉间区有或无刺细胞的分布,平行形的气孔器,脉区分布的硅细胞多为长方形边缘呈波状弯曲。看麦娘属植物叶下表皮的不同主要体现在脉间区长细胞的形状及平周壁的弯曲与否,脉间区短细胞出现或无,脉间区刺细胞的分布数量以及气孔器的列数。7种植物的叶表皮微形态的分类检索表据此列出。依据叶表皮微形态划分的组与根据外部特征划分的组并不完全一致。但是,由于该文仅研究了7种,叶表皮微形态对于看麦娘属的分类意义还需要更深入的研究。     

中国看麦娘属植物颖片与外稃微形态研究

通过扫描电子显微镜对中国看麦娘属7种植物的颖片和外稃微形态进行观察,以明确颖片和外稃微形态特征的系统分类学意义。结果显示:(1)看麦娘属颖片的长细胞为长筒状,细胞壁多为波状弯曲;短细胞为近圆形或肾形;气孔器常见或缺如或稀少;冠细胞密布或者稀少;刺细胞常见或少见;硅细胞的形状多为椭圆形或者近圆形。颖片的不同主要体现在冠细胞和气孔器的有、无及刺细胞的分布。(2)看麦娘属外稃的长细胞长筒状或短筒状,细胞壁波状弯曲;短细胞椭圆形或近圆形或近长方形;气孔器常见或无;刺细胞均常见;硅细胞多椭圆形或近圆形或长方形;冠细胞偶见或密布。外稃的不同主要体现在短细胞和气孔器的分布或缺如及硅细胞的不同形状。(3)对看麦娘属的颖片和外稃微形态特征进行聚类分析,看麦娘属植物分成了2个分支,分支Ⅰ由看麦娘、长芒看麦娘和日本看麦娘组成,分支Ⅱ包括苇状看麦娘、大看麦娘、短穗看麦娘和大穗看麦娘;7种植物的颖片和外稃微形态分类检索表依次列出。研究表明,颖片和外稃微形态特征都可以作为看麦娘属植物种间的分类依据,除短穗看麦娘外,颖片和外稃聚类分析的结果与看麦娘属内划分的组一致,颖片和外稃微形态支持短穗看麦娘划入sect.Alopecurus。     

山东莎草属叶表皮微形态的研究

利用光学显微镜对山东莎草属14个种和1个亚种植物的叶下表皮微形态特征进行研究,结果表明:脉间区长细胞为长筒形、短筒形,少数为近方形,边缘为波状、深波状;无短细胞存在;气孔器副卫细胞为三角形、圆屋顶形至三角形、高圆屋顶形和圆屋顶形;乳突存在于脉区长细胞上;刺毛仅存在于个别种中。根据脉区刺毛的有无,结合外部形态,可以分为有刺毛类型和无刺毛2个类型及4个亚类型。莎草属叶下表皮微形态特征高度一致,表明莎草属是一个自然类群,但在种间存在着一定的差异,可以为种的划分提供参考依据。     

中国蔷薇属植物叶表皮微形态特征及其系统学意义

应用光学显微镜和电子显微镜,对30种中国蔷薇属植物叶表皮的微形态特征进行了观察。结果表明:叶表皮细胞一般为多边形或不规则形,垂周壁平直、平直弓状、波状、浅波状和深波状式样;该属植物的叶表皮细胞大小种间差异较大,总体来看上表皮几乎全为多边形细胞,且上表皮细胞比下表皮细胞略大;在扫描电镜下观察,大部分细胞的平周壁下陷,仅部分细胞的平周壁突起;叶表皮角质层纹饰多样、即使同一个种的上下表皮细胞角质层纹饰微形态特征也有差异;大多植物叶片表面具柔毛,均为单毛,有长柔毛和短柔毛,大部分种类的柔毛基部无特化,其基部由普通的表皮细胞围绕着,少部分种类的柔毛基部由几个特化的辐射状细胞围绕着,少数植物无毛;有些植物叶表面或叶脉上还分布有腺毛;除了单叶蔷薇亚属的小蘗叶蔷薇1个种的上下表皮均分布有气孔器外,其余蔷薇亚属的29种植物的气孔器均分布在下表皮,形状为椭圆形、宽椭圆形和长椭圆形三种,气孔器类型有无规则型、不规则四细胞型、对位四细胞型、环列型和辐射型;气孔器外拱盖内缘近平滑或呈深浅不同的波状、气孔器外拱盖纹饰光滑或粗糙,大多植物气孔器的保卫细胞两级T型加厚;另外,只有小蘗叶蔷薇的气孔器具双层外拱盖且仅上表皮被毛等特征也说明了其在演化上的特殊地位,蔷薇属植物叶表皮的这些微形态特征,在属内各组间无明确的规律性,但可为探讨该属种间的分类学及亲缘关系提供依据。     

中国大蒜芥属(十字花科)叶表皮微形态学研究

利用光学显微镜观察了中国十字花科大蒜芥属9种1变种植物的叶表皮形态。结果表明：中国大蒜芥属植物叶上表皮细胞通常为多边形,垂周壁平直或弓形,少有稍浅波状,叶下表皮细胞为不规则形,垂周壁波状或深波状;气孔器类型均以不等细胞型为主,少有无规则型,偶有平列型。依据叶表皮特征,可将中国大蒜芥属划分为三种类型： （1）叶上表皮无气孔分布或偶见; （2）叶上表皮气孔常明显几个聚成一簇或排成短列,气孔密度小于叶下表皮; （3）叶上表皮气孔比较均匀分布,气孔密度与叶下表皮近相似。     

中国大蒜芥属（十字花科）叶表皮微形态学研究

利用光学显微镜观察了中国十字花科大蒜芥属9种1变种植物的叶表皮形态。结果表明：中国大蒜芥属植物叶上表皮细胞通常为多边形,垂周壁平直或弓形,少有稍浅波状,叶下表皮细胞为不规则形,垂周壁波状或深波状;气孔器类型均以不等细胞型为主,少有无规则型,偶有平列型。依据叶表皮特征,可将中国大蒜芥属划分为三种类型：（1）叶上表皮无气孔分布或偶见;（2）叶上表皮气孔常明显几个聚成一簇或排成短列,气孔密度小于叶下表皮;（3）叶上表皮气孔比较均匀分布,气孔密度与叶下表皮近相似。     

中国剪股颖属部分种叶下表皮微形态的研究

用光学显微镜对中国剪股颖属植物14种及1变种叶下表皮微形态特征进行了研究.结果显示:(1)剪股颖属植物叶下表皮长细胞多为长筒形,副卫细胞为平行形,脉上常见刺细胞,脉间有刺细胞或无或偶见,脉间具有短细胞或缺如;脉上硅细胞大多为结节形.(2)种间叶表皮的差异主要表现在脉间长细胞的形状及细胞壁的平直与否,气孔器分布的列数,脉间短细胞的有无,脉间刺细胞的有无,表明叶下表皮的差异可以作为种间的分类依据.(3)叶下表皮微形态的证据不支持山东剪股颖(Agrostis shandongensis F.Z.Li)作为玉山剪股颖(A.infirma Büse.)的异名处理,支持山东剪股颖和昆嵛山剪股颖(A.transmorrisonensis Hayata var.kunyushanensis F.Z.Li)的成立.并对昆嵛山剪股颖重新命名为[A.sozanensis Hayata var.kunyushanensis(F.Z.Li)F.Z.Li & C.M.Xu].     

中国罗汉松属叶角质层微形态结构及其分类意义

利用扫描电镜对罗汉松属8种2变种植物叶角质层内外表面进行了细致观察。发现罗汉松属植物叶角质层结构具有许多相似特征,表皮细胞较为规则,长方形或多边形,边缘波状弯曲;气孔器排列成带状,长轴均与叶脉一致,气孔器具较为明显的气孔塞和伏罗林环,气孔器保卫细胞极延伸明显,通常具有2~4个副卫细胞、不具极副卫细胞。但罗汉松属叶角质层结构也具有明显的种间差异,镰叶罗汉松和洛杉矶罗汉松同其它种类差异最大,这两种植物叶两面均具气孔器,角质层内表面垂周壁直,角质层凸缘不明显;贺氏罗汉松最为显著的特征是近轴面和远轴面表皮细胞的垂周壁角质层厚且凸缘均极其发达;小叶罗汉松近轴面表皮细胞排列较为规则,多数为方形,长轴与叶脉垂直,垂周壁之间的角质层突起较为显著,延伸到皮下层;兰屿罗汉松近轴面表皮细胞排列较不规则,多边形,细胞的角端比较钝,没有棱角;大理罗汉松气孔带间隔较小,有时两条气孔带挤在一起,使副卫细胞紧连,近轴面表皮细胞较短,方形或长方形,垂周壁之间的角质层较不发达;海南罗汉松角质层气孔带间隔较宽,气孔器形状为阔椭圆形,近轴面表皮细胞均为细长方形;变种短叶罗汉松和狭叶罗汉松与罗汉松也具有明显差异,短叶罗汉松近轴面表皮细胞排列不规则,垂周壁深波状弯曲,凸缘极为明显,但原种罗汉松近轴面表皮细胞排列较为规则,垂周壁浅波状弯曲,凸缘不明显,而狭叶罗汉松近轴面表皮细胞方形或长方形,比罗汉松的表皮细胞短,垂周壁直或略弯曲,角质层极厚。这些角质层微形态特征差异可以作为罗汉松属内种类分类鉴定的依据。     

山茶属的叶表皮形态及其分类学意义

在光学显微镜下观察了山茶属（Camellia)19个组36个代表种的叶表皮形态,发现上述植物的叶上下表皮细胞表面观形状均为不规则形,气孔器仅在下表皮存在,且一致为环列型;对上述植物中18个组30个种的叶下表皮进行扫描电镜观察,其特片为：气孔形状为梭形或长卵形,气孔外拱盖内缘光滑或呈浅波状,波状,气孔器附近的角质膜平坦或皱褶,表面光滑或有多种纹饰,这些特征可作为区分种或变种的依据,但与植物的外部形态等特征没有相关性。     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Host plants of someRhinanthoideae (Scrophulariaceae) of eastern North America

Twenty three species in 11 genera were examined in the field to determine hosts. OnlyStriga asiatica andSeymeria cassioides have a narrow host range being restricted to grasses and pines, respectively. These are the only species which cause pronounced and sometimes serious host damage. The other species attach to a great diversity of hosts.     

Apoptotic Regulation of Caspase Activity

Intracellular cysteine aspartate-specific proteases (caspases) play both signaling and effector roles in realizing the program of cell death. Caspases function as proteolytic cascades unique for each cell type and signal triggering apoptosis. All parts of the proteolytic cascades are duplicated and controlled by feedback signals. Amplification cycles between pairs of caspases (the third and the sixth, the ninth and the third, the twelfth and the sixth, and others) help multiply the initial apoptotic signal. The presence of physiological inhibitors of apoptosis that directly interact with caspases creates a multilevel regulatory network of apoptosis in cell. The caspase proteolytic cascades are also regulated by sphingolipid secondary messengers, among them ceramide, sphingosine, and their phosphates. Moreover, an association of the caspase signaling with ubiquitin-dependent proteolysis is shown in cells. In particular, the use of extracellular activators and inhibitors of caspases allows irreversible activation of apoptosis in tumor cells or the prevention of apoptosis in cortical neurons under neurodegenerative diseases.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Analysis of twin of eyeless regulation during early embryogenesis in Drosophila melanogaster

The Drosophila Pax6 homolog twin of eyeless (toy) is so far the first zygotically expressed gene involved in eye morphogenesis in Drosophila. The study of its expression during embryogenesis is therefore informative of the initial events of eye development in Drosophila. We have analyzed how the initial expression domain of toy at cellular blastoderm is regulated. We show that the three maternal patterning systems active in the cephalic region (the anterior, terminal and dorsal-ventral systems) cooperate with zygotically activated gap genes to shape the initial expression domain of toy. Whereas Bicoid, Dorsal and Torso signaling synergistically act as activators, Hunchback, Knirps and Decapentaplegic act as repressors.     

New species of Peruvian Orchidaceae III

Sixteen new species are proposed in the generaAckermania, Dressleria, Epidendrum, Maxillaria, Oncidium, Rodriguezia, Sigmatostalix, andTrigonidium. All new species are illustrated.Maxillaria vittariifolia L. O. Williams is newly recorded for Peru. A key is provided forTrigonidium of Peru.Trigonidium loretoense Schltr. andT. peruvianum Schltr. are lectotypified.     

Interaction of Synthetic Analogues of Natural Chalcones and Flavones with Guanidine

The reaction of chalcones and flavones with guanidine in ethanol results in 2-(2-aminopyrimidinyl-4)-phenols.     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.