中国羊胡子草、水蜈蚣二属果皮微形态特征的比较

利用扫描电镜对国产莎草科羊胡子草、水蜈蚣二属果皮微形态特征进行了比较观察和描述．根据果皮纹饰的差异，可将二属划分为两个类型：类型Ⅰ，具网状纹饰；类型Ⅱ，具网瘤状复合纹饰．在类型Ⅱ中，根据每一网眼中的瘤状突起数目及是否具小疣状附属物又可分为两个亚型．即网、单瘤亚型和网、复瘤亚型．研究结果表明：羊胡子草、水蜈蚣二属果皮微形态特征具有多样性、复杂性和稳定性等特点，可作为上述二属种间区别的依据．该研究对于探讨莎草科属间亲缘关系和系统发育也有一定意义     

中国－喜马拉雅柴胡属的花粉形态及其系统学意义

本文报道了中国－喜马拉雅柴胡属（ＢｕｐｌｅｕｒｕｍＬ．）２４种，７变种，２变型的花粉形态研究结果，全部在光学显微镜和扫描电镜下作了比较观察。有关柴胡属花粉形态的研究，除大苞柴胡（Ｂ．ｅｕｐｈｏｒｂｉｏｉｄｅｓＮａｋａｉ）和红柴胡（Ｂ，ｓｃｏｒｚｏｎｅｒｉｆｏｌｉｕｍＷｉｌｌｄ．）外．其余均为首次报道，根据该属花粉粒的形态和萌发孔特征，其花粉形态可分为三个类型，即：近菱形角孔类型、矩形边孔类型及其二者之间的过渡类型。花粉形态资料支持德国植物系统学家德鲁特（Ｏ，Ｄｒｕｄｅ，１８９８）关于柴胡属的系统位置，将其隶于芹亚科（Ａｐｉｏｉｄｅａｅ），芹族（Ａｐｉｅａｅ），葛缕子亚族（Ｃａｒｉｎａｅ）。     

国产山蚂蝗属植物花粉形态及其分类意义

目前对国产山蚂蝗属植物花粉形态的报道尚不系统,仅限于部分地区的少数种类.为向国产山蚂蝗属类群的分类学修订及系统关系探讨提供佐证,选取3亚属7组17种国产山蚂蝗属植物花粉,利用电镜扫描进行系统观察和比较分析.结果表明,本属花粉粒为单分体,单粒花粉球形、近长球形或长球形,具三孔沟.花粉粒外壁具网状,皱波状纹饰.根据花粉外壁纹饰对供试样品进行分类得到7个分类群,与宏观的形态差异有一定的对应性.测量和计算得到极轴长(P)、花粉沟长/极轴长(C/P)、花粉沟长/沟中部宽以及极轴长/赤道轴长(P/E)4个定量花粉形态数据,将编码后的纹饰分类结果与定量结果联合进行聚类分析,得到4个分类群,部分分类结果与宏观形态学分类吻合.对山蚂蝗属植物孢粉学性状的研究结果对其属下分类具有一定的参考和指导意义.     

中国—喜马拉雅柴胡属的花粉形态及其系统学意义

本文报道了中国－喜马拉雅柴胡属（Ｂｕｐｌｅｕｒｕｍ Ｌ．）２４种，７变种，２变型的花粉形态研究结果，全部在光学显微镜和扫描电镜下作了比较观察。有关柴胡属花粉形态的研究，除大苞柴胡（Ｂ．ｅｕｐｈｏ－ｒｂｉｏｉｄｅｓ Ｎａｋａｉ）和红柴胡（Ｂ．ｓｃｏｒｚｏｎｅｒｉｆｏｌｉｕｍ Ｗｉｌｌｄ．）外，其余均为首次报道。根据该属花粉粒的形态和萌发孔特征，其花粉形态可分为三个类型，即：近菱形角孔类型、矩形边孔类     

中国后生耳蕨组和新生耳蕨组（耳蕨属）的叶表皮解剖研究

利用光学显微镜对国产耳蕨属后生耳蕨组和新生耳蕨组３１个种４０个样品成熟叶表皮的细胞的形态特征的研究结果表明，后生耳蕨组和新生耳蕨组植物的气孔均分布在叶片下表皮，为气孔多形型，气孔基本类型有四细胞型和极型两种；气孔的类型、大小、气孔指数、表皮细胞形状等有一定的稳定性，可以作为后生耳蕨组和新生耳蕨组植物系统与分类研究的依据之一．     

游蛇科（Colubridae）10种蛇的随机扩增多态DNA研究

用随机扩增多态ＤＮＡ（ＲＡＰＤ）技术对游蛇科１０种蛇基因组ＤＮＡ的多态性进行了分子遗传标记的研究．所得数据经聚类分析结果提示：１．蛇类种内个体间存在着遗传多样性即个体间的差异，随机扩增多态ＤＮＡ片段共享度的分析表明，种间差异显著大于种内个体间的差异，说明在研究种间系统演化关系时．可以用随机取样的个体代表一个种作种间比较．２．锦蛇属是一高度分化的大属，本研究中的５种锦蛇间．玉斑锦蛇和红点锦蛇关系较近．可以井为１组．另３种归为１组还是分为３个不同的组尚难定论．３．游蛇科６个属之间．锦蛇属、乌梢蛇属和鼠蛇属３属间亲缘关系较近．Ｒｈａｂｏｐｈｉｓ和Ｓｉｎｏｎａｔｒｉｘ与链蛇属较近．它们可能代表该科中较原始的类群．     

中国崖爬藤属（TETRASTIGMA（MIQ．）PLANCH．）植物系统分类研究

崖爬藤属在中国物种分化特别多样。文中列出的国产种类是在对中国、印度支那半岛、印度半岛和喜马拉雅地区等植物种类的研究基础之上确定的。通过对上述不同地区存放在中国和法国巴黎自然历史博物馆（Ｐ）、英国邱园（Ｋ）及爱丁堡（Ｅ）皇家植物园等标本馆藏植物种类的比较研究，提出了本属植物的一个新分类系统，发表了国产的一些新分类群，也作了一些新组合。     

游蛇科（Colubridae）10种的随机扩增多态DNA研究

用随机扩增多态ＤＮＡ（ＲＡＰＤ）技术对游蛇科１０种蛇基因组ＤＮＡ的多态性进行了分子遗传标记的研究，所得数据经聚类分析结果提示，１．蛇类种内个体间在着遗传多样性妈个体间的差异，随机扩增多态ＤＮＡ片段共享度的分析表明，种间差异显著大于种内个体间的差异，说明在研究种间系统演化关系时，可以用随机取样的个体代表一个种作种间的比较．２．锦蛇属是一高度分化的大属，本研究中的５种锦蛇间，玉斑锦蛇和红点锦蛇关系的较     

川西山区苹果属（Malus）植物野生种表型相似性和地理亲缘

用表型数量分析方法，结合地理分布对川西苹果属11个野生种进行研究，探讨其种间关系与地理分布的联系．得结论如下：1．不同系数的WPGMA和UPGMA聚类结果基本相同．表型数量骤类分析能大体反映近缘种间的亲缘关系；2．滇池海棠与沧江海棠在形态上高度相似，聚类图上极靠近，分布上相重叠，在塑定上有时感到困难；3．花叶海棠与变叶海棠和稻城海棠与小金海棠，从表型及分布上看显然是地理替代种；4．本文所列各种，大都分属两大植物区系范围内，例如花叶海棠属中国-日本区东范围内，变叶海棠属中国-喜马拉雅区系范围内；5．发现沿康定-理塘-巴塘（约（N）30°）存在一条南北物种分布的分界地带线，称康-巴线；沿岷江上游和大渡河流域也存在一条明显的地带线，称岷江-大渡河带，这一带就是中国-喜马拉雅区系和中国-日本区系的交界地带，通过这一地带有些向南分布的种可以越过康-巴线以东地区到达金沙江边，向北分布的种有时也可越过康-巴线以东达到岷江上游。在这南北和东西交界带上，不同物种会集，无疑是物种分化以及种质渗入十分活跃的地带；6．与其它地区相比较，四川西部山区是我国野生苹果植物分化的多样中心。     

濒危植物邢氏水蕨和海南岛水蕨叶绿体序列rbcL比较及隐种分析

2021年,水蕨属（Ceratopteris）所有植物包括邢氏水蕨（C. shingii）、水蕨（C. thalictroides）和粗梗水蕨（C. pteridoides）被列为国家二级重点保护野生植物。水蕨属植物是研究植物性别决定、配子体形态建成以及遗传学、细胞生物学和生物化学等学科的模式植物之一,也是中国重要的野生水生植物种质资源。隐种（Cryptic species）问题已经成为系统分类研究、物种形成机制、生物进化和基于保护目的的种群遗传研究及保护计划共同关注的重要问题。基于叶绿体rbcL序列评价邢氏水蕨和海南岛陵水黎族自治县白水岭（BSL）、陵水黎族自治县木号镇（BJC）、海口城西镇（SPSK）等3个新发现的水蕨种群叶绿体序列rbcL的差异及系统发育关系,分析新发现尚未被评价的3个水蕨种群的隐种类型,为水蕨属不同物种和隐种的保护及利用提供科学依据。结果表明,邢氏水蕨和3个种群水蕨的rbcL序列长度为1 227 bp,邢氏水蕨有2个变异位点,分别在783 bp处和1 164 bp处。采用邻近法（NJ）构建了水蕨属叶绿体rbcL系统发育树。系统发育树显示BSL、BJC、SPSK等...     

Interrelationships of the two families constituting the Lophogastrida (Crustacea: Mysidacea) inferred from morphological and molecular data

The Lophogastrida are primitive Mysidacea and comprise only six genera. One of these, Eucopia is considered as highly specialized and constitutes the family Eucopiidae; the other genera constitute the Lophogastridae. Among the latter family, the genus Gnathophausia is closely related to Eucopia, with two species (G. gracilis and E. sculpticauda) sharing similar morphological characteristics [i.e. ornamentation (spines) of the uropods, and the gastric mill]. This indicates that these species are phylogenetically related. To test this hypothesis, the partial 16S mitochondrial ribosomal RNA gene from various representative species of Gnathophausia and Eucopia were compared. The resulting phylogenetic tree suggests that each genus is monophyletic, and that Gnathophausia, which is the deepest-branching genus, is the most primitive, with the Eucopiidae originating from the Lophogastridae. The molecular results support the morphological hypothesis, and suggest an early separation of the two genera or a rapid divergence of Eucopia due to morphological specialization. Received: 29 June 1997 / Accepted: 16 March 1998     

Seed trait changes in dispersers' guts and consequences for germination and seedling growth

The effectiveness of a frugivore as a disperser of a plant is greatly determined by how fruits and seeds are handled in its mouth and its digestive tract. Although a number of studies have investigated the effect of avian ingestion on germination, we still know very little about the modifications to seeds during ingestion and the specific consequences on plant fitness. Here we investigate for the first time the different mechanisms by which germination patterns of seeds are modified following ingestion by frugivores. Specifically, we examine changes in seed mass, water content, permeability, seed coat thickness, texture, and resistance in two common Mediterranean fleshy-fruited plants, Phillyrea angustifolia and Myrtus communis, after ingestion by Eurasian Blackbirds, Turdus merula. We found a number of differences between the plant species: Phillyrea seeds lost mass, mainly due to water loss, and had thinner coats after gut passage, but Myrtus seeds did not. Seeds of both species showed increased permeability, while Myrtus seeds in particular became less resistant to breakage. No quantifiable changes in seed coat texture were detected in either species, although this trait was partly associated with differences in germination rate in Phillyrea. High intraspecific plant variation was found for most seed traits measured. Seed passage through birds' guts sped up germination in both species, especially in Myrtus. Increased permeability in seeds of both species following ingestion resulted in a higher germination rate. Moreover, seeds with thick coats (and in the case of Phillyrea, harder coats) germinated at a slower rate and produced seedlings that also grew more slowly, indicating a cost of coat thickness and/or hardness for seedling emergence. Results obtained here contribute to explaining the great heterogeneity in germination responses among and within plant species and the large variety of factors, both intrinsic and extrinsic to the plants, that influence such responses.     

Costs and benefits of capsaicin-mediated control of gut retention in dispersers of wild chilies

A fundamental way in which animal-dispersed plants can influence the viability and distribution of dispersed seeds is through control of retention time in the guts of dispersers. Using two species of wild chilies and their dispersers, we examined how chemical and physical properties of fruits and seeds mediate this interaction. Capsicum chacoense is polymorphic for pungency, occurs in Bolivia, and is dispersed mostly by elaenias. Capsicum annuum is not polymorphic, occurs in Arizona (USA), and is dispersed mostly by thrashers. We first tested whether capsaicin, the substance responsible for the pungency of chilies, affects gut retention time of seeds in primary dispersers. Capsaicin slowed gut passage of seeds but did so in a manner that differed greatly between bird species because the constipative effects of capsaicin occurred only after an 80-minute time lag. Elaenias in Bolivia held only 6% of C. chacoense seeds for > 80 minutes, whereas thrashers in Arizona held 78% of C. annuum seeds for > 80 minutes. Next we examined the effects of retention time on seed viability and germination. Increased retention resulted in a greater proportion of seeds germinating in C. annuum, had no effects on non-pungent C. chacoense, and had negative effects on pungent C. chacoense. These divergent effects are explained by differences in seed coat morphology: seed coats of pungent C. chacoense are 10-12% thinner than those of the other two types of seeds. Thus, longer retention times damaged seeds with the thinnest seed coats. In C. annuum, seed viability remained high regardless of retention time, but germination increased with retention, suggesting a role for scarification. Thus, in C. annuum, fruit chemistry appears well matched with seed morphology and disperser physiology: capsaicin extends gut retention for most seeds, resulting in greater seed scarification and higher germination rates. Increased retention of pungent C. chacoense seeds is detrimental, but because the primary consumers have short retention times, capsaicin slows only a small proportion of seeds, minimizing negative effects. These results illustrate the importance of context in studies of fruit secondary metabolites. The same chemical can have different impacts on plant fitness depending on its morphological, physiological, and ecological context.     

Study of surface-shell features in thecosomata (Pteropoda: Mollusca) by means of scanning electron microscopy

The shell ornamentation of 6 species of Limacinidae and 2 species of Peraclididae has been studied by means of scanning electron microscopy. The author analyzes the phylogenetic relationships between the species considered and the morphologic resemblance with protoconchs of other Gastropoda. The function of some of the features observed is considered, and the relationship between adult and larval environments and shell formation discussed. Pteropoda do not exhibit conspicuous differences between veliger and adult shells, but there is quite an important difference between the protoconch and the rest of the shell, the former being very similar in several Gastropoda. The division of the genus Limacina into 3 subgenera, as proposed by Van der Spoel (1967), is also partially confirmed by the present study.     

Density dependence vs. independence, and irregular population dynamics of a swallow-wort fruit fly

Although most long-term studies of consumer-resource (e.g., predator-prey) interactions select species showing cyclic population dynamics, strong consumer-resource interactions can also produce irregular, noncyclic dynamics. Here, we present a case in which a seed predator, the tephritid fruit fly Euphranta connexa, shows fluctuations in density of more than two orders of magnitude over a 22-year period. To explain these fluctuations, we analyzed a stage-specific data set to quantify the density-dependent and density-independent components of larval survivorship and realized fecundity. Both larval survivorship and realized fecundity were strongly density dependent. Larval survivorship dropped from 0.62 at low larval density to 0.081 at high larval density, whereas fecundity dropped from 84.3 to 0.32 eggs per individual, more than a 100-fold decrease. We divided density-independent variation in E. connexa population dynamics into components for variability in (1) larval survivorship, (2) realized fecundity, and (3) annual fruit abundance. Of these components, 96% of the density-independent variance in per capita population growth rates was caused by fluctuations in fruit abundance. This highlights the importance of the strong consumer-resource interactions in driving fluctuations in E. connexa abundance. It also demonstrates that E. connexa dynamics are remarkably simple, and aside from the 4% of unexplained variance in per capita population growth rates, our understanding of E. connexa dynamics is remarkably complete.     

Body shape and burial behavior of the sand crab Emerita analoga (Stimpson 1857) in a reflective to intermediate morphodynamic range of sandy beaches

Sand crabs belonging to the genus Emerita are the dominant species on sandy beaches of the Pacific and Atlantic coasts of America. The success of this genus has been attributed to the great phenotypic plasticity of life history traits that enables them to cope with swash climate variability from beach to beach. The burrowing rate and variation in carapace shape of Emerita analoga from south-central Chile were studied on a series of five sandy beaches with contrasting reflective-intermediate swash conditions (harsher swash to benign swash). Environmental sampling was carried out monthly from September 2009 to November 2010, while biological experiments were conducted in September and October 2010. A combination of field experiments, geometric morphometric tools and multivariate analysis was used to assess the relationship between burrowing behavior and carapace shape with variables of swash climate. Our results showed that (1) body shape of E. analoga is directly affected by the frequency of effluent line crossing, (2) burrowing rate of E. analoga is affected directly by shape variability, (3) burrowing rate is affected directly and indirectly by the swash climate variables: frequency of effluent line crossing and mean grain size of sediment. Thus, the physical conditions in the intertidal zone may be the main environmental constraints determining cephalothorax shape, with a wider cephalothorax on beaches with finer sand and more benign physical dynamics, and a narrower shape on beaches with coarser sand and harsher physical dynamics. The latter phenotype (narrower shape) probably allows compensating the high difficulty of burying in coarser sediments.     

Identification of archaeogastropod larvae from a hydrothermal vent community

Dispersal is essential in order that endemic species living in ephemeral, patchy vent environments may persist over evolutionary time. Quantitative field studies of larval dispersal, however, require specieslevel identification of the larval forms because each individual must be distinguished from related vent species, and from non-vent species living in the surrounding deep-sea environment. Methods for culturing these larvae to an identifiable stage have not yet been developed. To solve the larval identification problem for the archaeogastropod molluscs (a prominent component of vent communities), we used a scanning electron microscope (SEM) to image shells of larvae collected in the water column near vents along the East Pacific Rise (9°40′ to 9°50′N; 104°W). Larval shell size, shape and ornamentation were compared to protoconchs retained in juvenile or adult shells of identified species, and used to assign five larval groups unequivocally to species (Cyathermia naticoides Warén and Bouchet, 1989; Neomphalus fretterae McLean, 1981; Clypeosectus delectus McLean, 1989; Rhynchopelta concentrica McLean, 1989; and Lirapex granularis Warén and Bouchet, 1989) and seven groups tentatively to species or genus [Lepetodrilus spp. (three groups); Gorgoleptis sp; Peltospira ?operculata McLean, 1989; and ?Melanodrymia sp. (two groups)].     

Genetic structure across the GBR: evidence from short-lived gobies

The Great Barrier Reef (GBR) exhibits distinct cross-shelf zonation. These patterns are particularly well documented in reef fishes and have been attributed to either environmental gradients (e.g. wave energy, oceanography) or barriers to gene flow. This study examined the extent to which barriers to gene flow contribute to cross-shelf patterns by examining the mitochondrial DNA of gobies (genus Eviota). The genus Eviota was selected due to its extreme life history characteristics (shortest vertebrate lifespan) and cross-shelf distribution patterns (E. queenslandica, inner- and mid-shelf, and E. albolineata mid- and outer-shelf). Although cross-shelf barriers to gene flow were predicted, this study found no population structure between shelf locations. However, a genetically distinct population of E. queenslandica (the inner-shelf species) was observed at North Direction Island (Phi_st = 0.088, P = 0.004). As no comparable structure was observed in E. albolineata (the outer-shelf species) it may be that habitat type (E. queenslandica = reef lagoon, E. albolineata = reef crest) is a significant factor driving the structure observed in E. queenslandica. Larval behaviour, olfactory or auditory senses and reef selection at settlement could be assisting larvae to return to reefs similar to natal reefs. We suggest that ecological gradients are more important than barriers to gene flow in structuring cross-shelf distributions within Eviota.     

Partial purification and anti-leukemic activity of L-asparaginase enzyme of the actinomycete strain LA-29 isolated from the estuarine fish, Mugil cephalus (Linn.)

The actinomycete strain LA-29 isolated from the gut contents of the fish, Mugil cephalus of the Vellar estuary showed excellent L-asparaginase activity The enzyme was purified 18-fold and the final recovery of protein was 1.9%, which exhibited an activity of 13.57 IU/mg protein. The partially purified L-asparaginase inhibited the growth of leukemia cells in male wistar rats. Average survival period of the rats was more in an optimum enzyme dose of 100 units and the survival period was less when the dosages were increased and at the same time the enzyme became less effective when the dosages were decreased. Higher survival of 17.2 days was recorded when 100 units of the enzyme was given in three intermittent doses (50/25/25 units) at the interval of 24 hr. Analysis of cell components of the strain LA-29 has revealed the wall type-I which is the characteristic of the genus Streptomyces. Further the morphological, physiological and biochemical features along with the micromorphological results obtained for the strain LA-29 were compared with that of the Streptomyces species found in Bergey's Manual of Determinative Bacteriology and the strain LA-29 has been tentatively identified as Streptomyces canus.