盐度对裸项栉鰕虎鱼繁殖和生长的影响

目的探索裸项栉鰕虎鱼繁殖和育苗的适宜盐度。方法比较不同盐度梯度条件下裸项栉鰕虎鱼的产卵率、孵化率和生长存活情况。结果裸项栉鰕虎鱼性腺成熟、产卵和孵化的适宜盐度为10‰-20‰,过低或过高盐度该鱼产卵量少,孵化率极低;适宜的盐度有利于裸项栉鰕虎鱼的生长。结论裸项栉鰕虎鱼适盐范围广,适宜的繁殖、生长盐度较低。     

盐度对新吉富罗非鱼受精卵孵化和仔稚鱼活力的影响

研究了盐度梯度对新吉富罗非鱼(Oreochromis niloticus)受精卵孵化和仔鱼活力的影响。水温(28±0.5)℃下,观察比较了8个梯度的盐度(3‰、6‰、9‰、12‰、15‰、18‰、21‰、24‰)及纯净淡水(盐度为0)条件下,新吉富罗非鱼受精卵的孵化时间、孵化周期、孵化率和畸形率。同时在不同盐度条件下对4批初孵仔鱼进行耐饥饿实验,测定其不投饵存活系数(SAI)值。结果表明,新吉富罗非鱼受精卵在盐度6‰～15‰时,孵化率较高(89.0%～92.7%);盐度低于3‰和高于18‰时,孵化率较低。仔鱼生存适宜盐度3‰～15‰,最适盐度6‰～9‰。新吉富罗非鱼仔鱼在盐度0～3‰及18‰～24‰时,仔鱼的SAI值较低,不适宜仔鱼培育;盐度为6‰～15‰时,仔鱼的活力较高。仔鱼的SAI值与受精卵的孵化率呈正相关关系。     

盐度及pH对星斑裸颊鲷受精卵孵化和仔鱼耐饥饿能力的影响

比较观察了不同盐度(0、5‰0、10‰、15‰、20‰、25‰、30‰、35‰、40‰和45‰)及不同pH(5.5、6.0、6.5、7.0、7.5、8.0、8.5、9.0和9.5)条件下,星斑裸颊鲷(Lethrinus nebulosus)受精卵的孵化时间、孵出期、孵化率、畸形率及一定时间内(24h和48h)仔鱼成活率,并且在以上盐度和pH条件下对星斑裸颊鲷初孵仔鱼进行耐饥饿试验,测定其不投饵存活指数(survival activity index,SAI).结果表明,只有SAI值大于3的星斑裸颊鲷仔鱼才有可能被进一步培育成苗,低于3的将在数天内死亡;星斑裸颊鲷受精卵孵化的适宜盐度范围是10‰～45‰,最适宜盐度范围15‰～40‰,适宜pH是6.5～9.0,最适宜pH范围7.0～8.5;初孵仔鱼生存的适宜盐度范围是10‰～40‰,最适宜盐度范围20‰～25‰,适宜pH是5.5～9.5,最适宜pH范围7.0～8.5.     

盐度对无瓣海桑幼苗的生长和某些生理生态特性的影响

本文研究了盐度(0‰～50‰)对无瓣海桑幼苗生长的影响。盐度对无瓣海桑幼苗长叶数、茎长、植株鲜重、主根长、根系鲜重等方面起抑制作用;随盐度的提高,无瓣海桑幼苗成活率下降;但盐度对无瓣海桑幼苗叶片面积存在一个低盐(0‰～10‰)促进、高盐(15‰～40‰)抑制的过程;盐度对叶绿素含量的影响总趋势是随盐度提高,低盐时叶绿素含量下降,而当盐度超过10‰时上升。因此认为：1)无瓣海桑幼苗在无盐存在下,也可正常生长;2)无瓣海桑具有较高的耐盐能力,在盐度0‰～25‰内可正常生长,超过25‰,其生长受到抑制。     

盐度对暗纹东方鲀生长、非特异性免疫和抗氧化酶活力的影响简

实验比较不同盐度处理对暗纹东方鲀(Takifugu obscurus)的生长、非特异性免疫和抗氧化酶活力的影响。实验设置6‰、12‰、18‰、24‰和30‰5个盐度处理组,淡水组设为对照组。分别在实验的第1、第5、第10、第15、第20、第30、第40和第50天进行取样测定,并进行溶菌酶、碱性磷酸酶、超氧化物歧化酶和过氧化氢酶活力测定。当盐度≤18‰时,鱼的生长受影响较小,而在盐度为24‰和30‰的高盐度组中鱼体生长受到较大抑制,并且死亡率随着盐度的增加而增高。经盐度处理后,溶菌酶和碱性磷酸酶活力先逐渐增加,在达到最高峰后又逐渐降低,在24‰和30‰的高盐度组中,最终酶活力显著低于对照组水平。超氧化物歧化酶和过氧化氢酶的活力也呈现出先增加后降低的趋势,最终保持与对照组相似的水平。结果表明,高盐度(24‰和30‰)对暗纹东方鲀的生长、非特异性免疫和抗氧化酶活力均有显著的影响。     

盐度对红树植物海莲幼苗的生长和某些生理生态特性的影响

本文主要探讨了不同盐度海水砂培的海莲幼苗生长量和某些生理生态特性与盐度的相关效应。结果表明,生长基盐度20‰以上,海莲繁殖体的萌苗时间推迟,成活率降低;随着盐度的提高,幼苗高生长量降低,叶片变小;叶片叶绿素含量随盐度提高而提高,相反的叶片可溶性糖含量则降低,而叶片可溶性蛋白质含量变化不明显;叶片组织内氯含量随盐度提高而提高;随着盐度的提高,叶片蒸腾作用减弱,气孔导度降低。由此表明,海莲幼苗适宜生长的盐度范围在15‰以下,更高的盐度表现为生态抗盐适应性生长。     

温度和盐度对青蛤孵化及幼虫、稚贝存活与生长变态的影响

在9个温度梯度(10-34℃)和10个盐度梯度(盐度3‰-50‰)条件下,研究了温度和盐度对青蛤孵化及幼 虫、稚贝生存与生长变态的影响。结果表明,青蛤孵化和浮游幼虫生长的适温范围为24-32℃,最适温度均为26- 30℃,稚贝生长的适温范围为22-32℃,最适温度为24-30℃。在最适温度下,D形幼虫变态率达80．7％-88．2％, 浮游幼虫和稚贝的存活率分别为86．2％-88．7％和81．5％-84．0％;孵化及浮游幼虫的生长适宜盐度为15‰- 30‰,稚贝为10‰-35‰,最适盐度均为20‰-25‰。在最适盐度下,D形幼虫的成活率、变态率、生长速度皆最高, 分别达到86．9％、77．5％和9．38×11．0μm/d,匍匐幼虫经14-14．5d发育至双管期稚贝,至双管期稚贝的成活率 82．5％-85．0％,日平均生长达13．1μm以上。与大多数滩涂贝类一样,青蛤属于广温广盐性贝类,且稚贝对低盐的 适应能力强于对高盐的适应能力。     

海水盐度、温度对文蛤稚贝生长及存活的影响

在实验室条件下,研究了不同盐度（19个梯度）、温度（17个梯度）对文蛤稚贝生长和存活的影响.结果表明：文蛤稚贝的适宜生存盐度在6.5～39.5,最适生存盐度在9.0～31.0,适宜生长盐度在7.3～38.7,最适生长盐度在15.0～23.0;其适宜生存温度在4.0 ℃～36.1 ℃,适宜生长温度在7.0 ℃～35.4 ℃,较适宜生长温度在17 ℃～33.5 ℃,最适生长温度在24 ℃～27 ℃.文蛤稚贝对高温度、低盐度有较强的适应性.     

红树植物秋茄和海莲幼苗过氧化物酶对栽培盐度条件的反应

本文探讨了系列海水盐度砂培的红树植物秋茄和海莲幼苗叶片、根尖的过氧化物酶活性及其同工酶对不同盐度条件的反应。结果表明：(1)秋茄苗：在低盐度0‰至10‰范围,叶过氧化物酶活性随盐度提高而略有增强,15‰以上则降低;根尖过氧化物酶活性则不同,随盐度(0—35‰)提高而降低。(2)海莲苗：随其生长基盐度(5—25‰)提高,叶过氧化物酶活性迅速降低,而根尖过氧化物酶活性在5‰至10‰盐度时略有提高,15‰以上迅速降低;而后高盐度(25一35‰)活性降低不明显。这表明,在盐度的影响下,秋茄苗过氧化物酶活性变化程度小而海莲大。(3)在同工酶谱表现上,两种植物幼苗(叶,根)均为主级酶带受盐度影响不明显,但次级酶带对盐度敏感。     

实验室培养下温度和盐度对底栖有孔虫Ammonia aomoriensis (Asano,1951)存活和生长的影响——基于形态测量

在三个温度(6℃,12℃和18℃)和四个盐度(20‰,25‰,30‰和35‰)完全交互条件下,对中国近海常见底栖有孔虫Ammonia aomoriensis活体进行单个体分组培养实验,每组12个体,实验周期为28d,每两天测量虫体长径和短径、记录房室数目和存活情况,以研究温度和盐度对A.aomoriensis存活、生长和形态变化的影响。统计结果显示,在实验设计的温度和盐度范围内,低温对其存活具有抑制作用,6℃时虫体出现死亡早且最终存活率低,而盐度无明显影响;温度对A.aomoriensis长径和短径的生长均有极显著的影响(p0.001),随着温度升高,生长加快;盐度对A.aomoriensis长径和短径的生长均无显著的影响。实验设计中最适宜的18℃时,两圈房室以上的A.aomoriensis每生长一个房室平均时间3.5-7d,长径和短径的生长速率分别为0.7~1.3μm/day、1.2~1.9μm/day。培养结束后A.aomoriensis的虫体长宽比与温度显著相关(p0.05),与盐度无显著相关,且温度升高,个体长宽比减小,形态更接近于圆形,推测其可以作为指示温度变化的指标。温度和盐度对A.aomoriensis的交互作用在长径的生长中显著,在短径的生长和长宽比中不显著。本研究结果表明,在实验室培养条件下,相比于盐度,温度对A.aomoriensis存活、生长和形态变化影响更显著。     

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.