东北地区蒲公英属瘦果微形态特征及其分类学意义

通过对东北地区10种蒲公英瘦果形态及微形态特征进行观察比较,为蒲公英属（Taraxacum F.H.Wigg.）分类研究提供瘦果形态学证据。利用体式数码光学解剖镜和电子探针显微镜,对蒲公英瘦果进行观察比较,并根据瘦果大小、形状、喙基比例、颜色及微形态表面纹饰特征进行聚类检索。结果表明,（1）瘦果微形态特征为全身具刺,具白色斑点,刺状突起成行且规则排列,但刺大小及密度存在显著差异;（2）检索结果表明,以蒲公英瘦果形态及微形态特征进行检索的结果与《中国植物志》中的分类结果一致。该实验通过对东北地区10种蒲公英瘦果形态及微形态特征进行描述,确定了蒲公英瘦果形态特征差异可作为分类学表征证据,并将喙基长度（B）与瘦果长度（A）（不包括喙基长）之比命名为喙基比（B/A）,该比值可增补为分类要点。研究结果支持《中国植物志》中对蒲公英属的分类结果。     

莴苣属6种近似种瘦果形态的扫描电镜观察

【目的】研究莴苣属6种近似种瘦果超微形态,确定鉴别特征,为口岸检疫鉴定提供参考。【方法】利用扫描电子显微镜观察莴苣属6个近似种瘦果的表面特征、冠毛、种脐、衣领状环等超微形态特征,测量瘦果表面刺长、刺宽、刺间距、冠毛节间长度等,并应用单因素方差分析进行显著差异评价。【结果】野莴苣脐口无环形边,其他5种均具环形边;野莴苣瘦果表面突起呈锐三角状物,乳苣突起呈耳状物;乳苣与莴苣衣领状环呈圆形或近圆形,其他4种呈椭圆形;乳苣、刺毛莴苣冠毛节间长度最小,毒莴苣的最长;野莴苣、莴苣、山莴苣次之;毒莴苣瘦果冠毛上的刺基部稍肿大,而其他5种未见肿大;瘦果超显微特征性状测量值在种之间存在差异。【结论】莴苣属种脐的形状和环形边的有无、种脐中央的突起物形状、衣领状环形状、瘦果表面纹饰特征及突起物的形状等超微形态特征可以作为莴苣属种类判定依据;瘦果表面的刺长度和宽度、刺间距、冠毛节间长度数值差异显著可以用于莴苣属种类鉴定。     

北京7种鬼针草属植物果实微形态特征及其系统学意义

采用扫描电镜方法对北京地区鬼针草属植物7个种的果实微形态特征进行了观察、比较。结果表明:(1)7种鬼针草属植物瘦果的果体形状、表面棱的数目、芒刺(冠毛)数目及其上倒刺数目和生长位置等特征可以作为鉴定各种的重要形态学依据。(2)根据果皮在扫描电镜下表面纹饰类型及表皮细胞形状等特征,可将7种鬼针草分为两类:一类果皮表面为典型的网纹纹饰,表皮细胞呈不规则多边形,细胞界限明显;另一类果皮表面为条状网纹或纵条纹纹饰,表皮细胞呈长圆形或长条形,细胞界限不明显。由于7个种的果皮表面纹饰有着明显的差异和各自的特点,并与根据叶形、地理分布及分子等证据得出的系统亲缘关系结果基本相符,表明这一特征可能具有一定的系统学意义。     

中国广义冰岛蓼属果实形态特征

应用扫描电镜对冰岛蓼属（Koenigia L.）8个物种的果实形态与果皮微形态进行了观察。结果表明,这些果实可分为3类：类型Ⅰ：瘦果长卵形至宽卵形,中部或中上部最宽,双凸镜状或3棱状,棱脊有或无;表面粗糙或光滑,具纵向断棱状纹饰,或具波状纹饰,这种类型有冰岛蓼、铜钱叶蓼、青藏蓼、大铜钱叶蓼4种;类型Ⅱ：瘦果卵形,中部膨大,具有3棱脊,但棱脊不显著。这种类型仅小叶蓼1种;类型Ⅲ：瘦果卵形,中间最宽但不膨大,具有3棱脊,且棱脊显著;表面光滑,具多皱纹饰,或凹凸不平纹饰,或具疣状纹饰,这种类型包括细茎蓼,蓝药蓼和柔毛蓼3种。研究结果支持将柔毛蓼与蓝药蓼作独立分种处理、而冰岛蓼与青藏蓼关系很近。     

基于MaxEnt模型的对开蕨在吉林省的潜在适生区预测

目的：明确国家Ⅱ级重点保护野生植物对开蕨的潜在适生区，分析影响其适生区分布的主导环境因子，是对其种群开展保护和恢复的基础。方法：基于现有的对开蕨分布点和环境数据，利用MaxEnt模型预测对开蕨在吉林省的潜在适生区并划分适生等级，进而以刀切法，结合每个环境因子的贡献率和置换重要值来综合评估影响对开蕨分布的主导环境因子。结果：训练集的受试者工作特征曲线下的面积(AUC)平均值为0.991，测试集的AUC平均值为0.987，表明MaxEnt模型预测结果准确。对开蕨的潜在适生区主要分布于吉林省东南部的白山市和通化市，辽源市、吉林市和延边州也存在零散分布，而白城市、长春市、松原市和四平市均为非适生区，其中高适生区潜在分布面积共计2 139.67 km²，中适生区潜在分布面积共计2 950.20 km²，低适生区潜在分布面积共计7 309.44 km²。影响对开蕨潜在分布的4个主导环境因子为最暖季度的降雨量、海拔、坡度和最冷月的最低温度，其适宜阈值分别是500～560 mm、700～1 250 m、14°以上和-25.5～-23.5...     

星果泻属的果实形态特征及其分类学意义

利用解剖镜和扫描电子显微镜详细观察了泽泻科星果泻属全部5种植物的果实形态和微形态特征,发现该属植物的果实：常为蓇葖果具2～6枚种子;稀瘦果具1枚种子,扁压,不规则长方形,顶端一侧延伸成尾状长喙;或果实三角形,喙不明显。果皮上有角质层覆盖,角质层的纹饰为条状或细条状,上面密被碎屑状、颗粒状或稀疏的颗粒状蜡质附属物。这些特征可作为属下分类的依据。本文在前人研究的基础上对该属的分类进行了讨论并写出新的分种检索表。笔者认为将星果泻和星状星果泻各自作为独立的种可能更为合理;加州星果泻仍应放在星果泻属内,而星果泻则可能是加州星果泻与该属其它种联系的一个中间过渡类型;多籽星果泻不宜与星果泻全并,仍应保留为一独立的种。笔者还首次发现该属植物的果皮上分布有气孔。     

不同寄主上桃粉大尾蚜的取食偏好及形态变异研究

【目的】桃粉大尾蚜Hyalopterus pruni Geoffroy是一种常见的农业害虫,分布广泛。本文对采自上海地区粘核毛桃Amygdalus persica L.var.scleropersica(Reich.)Yüet Lu、紫叶李Prunus cerasifera Ehrhar f.atropurpurea(Jacq.)Rehd.和芦苇Phragmites australis(Cav.)Trin.ex Steud.3种植物上桃粉大尾蚜的取食偏好和形态变异进行了研究。【方法】通过叶碟法观测桃粉大尾蚜对3种寄主叶片的取食偏好,同时测量体长、体宽、触角各节长、喙末端长和宽、各足节长等30个形态指标,基于对形态数据的统计分析,包括主成分分析、聚类分析和判别分析,研究不同寄主植物上桃粉大尾蚜的形态变异。【结果】饲以3种寄主植物叶片时,来自粘核毛桃和芦苇上的桃粉大尾蚜对各寄主叶片的总体喜食程度依次为芦苇>粘核毛桃>紫叶李,来源于紫叶李上的个体对3种叶片的喜食程度为芦苇>粘核毛桃=紫叶李;形态数据分析发现粘核毛桃和紫叶李上的桃粉大尾蚜各指标间均无显著差异(P>0.05),但二者与芦苇上的个体在触角节Ⅱ、触角末节鞭部长、喙末端长和中足胫节的长度间差异显著(P<0.05),紫叶李与芦苇上的个体前足跗节Ⅰ长这一指标差异显著(P<0.05),此外,主成分分析筛选的体长、头宽、触角各节和各足长度等特征构成的前四个主成分对总体方差的累计贡献率达到66.206%,其中贡献率较高的特征为触角和各足节长度,系统聚类和典型判别分析的结果显示采自芦苇上的桃粉大尾蚜区别于粘核毛桃和紫叶李上的,归为一类,同为蔷薇科植物的紫叶李和粘核毛桃上的桃粉大尾蚜克隆有小部分重叠。【结论】禾本科植物上的桃粉大尾蚜种群形态特征与蔷薇科植物上的相比,触角节Ⅱ和末节鞭部、喙末端长、中足胫节的长度存在一定的分化,初步推测造成桃粉大尾蚜形态分化的原因主要为寄主植物营养成分及其表面特征,其种内变异的具体机制仍需进一步探索。     

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.