渤海西岸急性致死性对虾病的病毒病原研究

目前,在全世界养殖及野生对虾中已发现至少有10～20种病毒。近年来,我国沿海省份相继发生养殖对虾大批死亡现象,造成大部分虾场严重减产甚至绝收,对滩涂对虾养殖业造成巨大经济损失。虾病已成为对虾养殖业的重要限制因素。因此研究虾病的病原,传染途径,对有效防治暴发流行性虾病,发展对虾养殖业具有重要意义。本文报导我们对渤海西岸养殖的中国对虾暴发流行病病原的部分研究结果。1材料与方法1．五病好和病虾组织的超薄切片观察病虾取自辽宁锦西首钢前所虾场加工厂冰冻中国对虾,以及上海东海水产研究所固定保存的活病虾组织。从已死…     

中国对虾两种球状病毒的免疫检测

以江苏、河北某虾场病虾组织中提取的对虾的两种球状病毒作为抗原,制备出特异性强、效价较高的抗血清,用对流免疫电泳,酶联免疫吸附,免疫电镜技术对五个不同地区的病虾材料进行检测,结果表明：江苏、青岛、河北地区的病虾组织中均含有相应的球状病毒病原。     

两种病毒侵染中国对虾后细胞超微病理学变化与免疫标记

应用电子显微技术研究人工感染的中国对虾病毒病原及其宿主细胞超微病理学变化。结果显示病虾体内存在球状与杆状两种病毒病原,有时在同一病虾组织的同一细胞中可见两种病毒同时侵染现象,该现象提示存在复合感染的可能。利用胶体金免疫标记技术对感染病虾细胞质中出现的球状病毒作定位标记,初步结果表明已分离提纯的球状病毒与感染病虾细胞质中观察到的病毒粒子性质基本相同。病毒侵染后,细胞内主要的细胞器如线粒体、内质网、核糖体均发生了显著变化;侵染后期,可见溶酶体及多种膜性结构大量增生、细胞核被一些微管样结构包裹等特殊变化的发生。     

日本沼虾三群体线粒体16S rRNA基因片段序列的差异与系统进化

通过对日本沼虾(Macrobrachium nipponense)3个群体线粒体DNA 16S rRNA基因片段进行扩增和测定,得到长度为495bp的片段,其碱基A、T、G和C的平均含量分别为28.6%、36.1%、22.7%和12.5%,AT含量明显高于GC含量。通过对日本沼虾16SrRNA基因片段遗传特征的研究发现其种内变异很小,在3个群体中只有5个位点发生转换。另外,利用其454bp的同源序列,以中国明对虾(Fenneropenaeus chinensis)为外群探讨了沼虾属日本沼虾、罗氏沼虾(M.rosenbergii)等8种沼虾的系统进化关系。用MEGA3.1软件中的NJ法构建的分子进化树,日本沼虾3个群体先聚在一起后与海南沼虾聚在一起;另外,罗氏沼虾与马氏沼虾、短腕沼虾与贪食沼虾亲缘关系较近先聚在一起,然后再与大臂沼虾和等齿沼虾聚在一起,最后才与外群中国明对虾聚在一起。     

中国对虾虾病病原菌的分离、回接和鉴定

中国对虾(Penaeus orientalis ki-shinouye)是价随很高的水产品,近年来随着人工养虾面积的不断扩大,虾病也不断蔓延,严重影响了对虾的产量。对虾病原菌的分离、纯化、回接、鉴定和防治的研究,具有重要的实践意义。我们从辽宁省的丹东、营口、锦州、     

原位杂交研究对虾白斑杆状病毒在虾体内感染过程

应用地高辛标记的对虾白斑杆状病毒（ｗｈｉｔｅ ｓｐｏｔ ｓｙｎｄｒｏｍｅ ｂａｃｕｌｏｖｉｒｕｓ,ＷＳＳＶ）核酸探针,与人工感染后不同时间采集的对虾组织样品进行原位杂交,以动态研究病毒从侵染至对虾以病死亡的过程。将典型感染ＷＳＳＶ的病虾组织投喂健康对虾,结果显示：ＷＳＳＶ道德通过侵染消化道上皮进入虾体内增殖,此后随着细胞裂解、病毒粒子释放,游离的粒子伴随血淋巴循环进而杂其它靶组织,直至对虾发病死亡     

对虾病毒病害的研究进展

随着对虾养殖业的发展,其病害亦日趋突出。对虾病原的研究,特别是病毒性病原的研究,是当前我国发展对虾养殖业的重要课题,它对虾病的防治与检测提供重要的科学依据。为此,我们对近十多年来已发表的有关对虾病毒方面研究的论文和资料作一概述,希望能对同行的研究工作有所稗益。l对虾病原的研究l．且国外已发现的对虾病毒种类自1974年Cou。h【‘’报道了第一种对虾病毒以来,共发现了15种病毒或似病毒颗粒：对虾杆状病毒（BP）、对虾中肠腺坏死病毒（BMNV）、斑节对虾杆状病毒（MBV）、对虾传染性皮下与造血器官坏死病毒（IHHNV）…     

斑点杂交检测对虾白斑综合征病毒青岛株在螯虾体内的动态分布

近年来 ,我国学者对人工养殖对虾暴发性病毒病的病原进行了较为系统的研究[1～ 5] ,本试验应用螯虾这一动物模型[6] ,利用斑点杂交方法 ,研究了白斑综合征病毒 (ＷＳＳＶ ,前称无包埋体对虾病毒Ｎｏｎ -Ｏｃｃｌｕｄｅｄ -ＳｈｒｉｍｐＶｉｒｕｓＮＯＳＶ )青岛株在螯虾体内的动态分布 ,为研究该病毒的传播途径、增殖致病机理提供了参考。1　材料与方法1.1　实验动物克氏原螯虾 (Ｃａｍｂａｒｕｓｐｒｏｃｌａｒｋｉｉ ,以下简称螯虾 ) 40尾 ,购自南京某农贸市场 ,实验室饲养一周以上 ,健康存活。1.2　种毒处理及接种白斑综合征病毒青岛株 (…     

中国对虾杆状病毒基因克隆及探针制备与检测

从收集的中国对虾（Ｐｅｎａｅｕｓｃｈｉｎｅｎｓｉｓ）病虾样品中分离到一种杆状病毒,经负染在电镜下观察,完整病毒粒子大小为１１０×２８０～３２０ｎｍ。病毒核酸经ＥｃｏＲＩ酶切,克隆到ｐＵＣ１８质粒上,经筛选得到两个克隆Ｌ４６、Ｍ１３,克隆片段分别为２．１４ｋｂ和３．５８ｋｂ。将这两个基因片段和对虾白斑综合征杆状病毒（ＷｈｉｔｅＳｐｏｔＳｙｎｄｒｏｍｅＢａｃｕｌｏｖｉｒｕｓ,简称ＷＳＳＶ）基因克隆片段Ａ２６制备探针,共同用点杂交法对我国沿海地区的病虾样品进行检测,以了解我国沿海地区对虾杆状病毒的分布,并确定中国对虾杆状病毒与ＷＳＳＶ的同源性。     

欧文氏弧菌毒力蛋白PirAB的原核表达与纯化

对虾肝胰腺坏死病的爆发造成了对虾养殖产业的严重亏损。从上海地区凡纳滨对虾中分离出1株欧文氏弧菌(Vibrio owensii SH-14),该菌株可导致凡纳滨对虾死亡,且死虾出现对虾肝胰腺坏死病的典型症状。经PCR扩增欧文氏弧菌毒力蛋白PirA与PirB对应基因序列,并将其连接到表达质粒pET-21b(pirA)和pGEX-4t-1(pirB)。通过优化诱导表达和亲和层析纯化条件,最终获得大量高纯度的目的蛋白。经冷冻干燥保存为后期抗体合成以及进一步毒力效应研究提供参考。     

克隆植物种子繁殖和营养繁殖的适合度分析和度量

植物种群繁殖的适合度指繁殖行为适应环境变化的能力及其对各群更新发展的贡献,不仅表现在个体水平也表现在基因水平。提出度量种子繁殖和营养繁殖在个体和基因水平的适合度的计算公式,并计算了白三叶草繁殖的适合度,较好地解释了种子繁殖和营养繁殖对克隆植物种群更新发展朱同作用。     

人工油松种群生长与生殖分配关系的研究

植物种群营养生长和生殖生长的关系是植物生殖生态学研究的重要内容之一,自本世纪70年代,国外已有大量报道,但国内的研究报道很少。本文在种群水平上研究了人工油松种群一年生雌性枝条和雄性枝条在枝长、直径、叶数、叶生物量、枝生物量及新生枝条在大小孢子球生物量、雌雄枝条长度和生物量等方面的差异,结果表明,一年生枝条除在西方向上雌雄枝条直径差异显著和在东、西方向上雌雄枝条生物量差异显著外,其它处理条件下雌雄枝条在长度、直径、叶数、叶生物量和枝生物量等方面差异均不显著;而对新生枝条的取样分析表明同方向上雌雄枝条在大小孢子球生物量、雌雄枝条长度、雌雄枝条生物量等方面差异均显著或极显著。无论是一年生枝条,还是新生枝条,在东、西、南、北四个方向上其各项指标差异显著或极显著。     

COST OF REPRODUCTION IN POLEMONIUM VISCOSUM: PHENOTYPIC AND GENETIC APPROACHES

I measured the effect of early reproduction on subsequent growth and survival in the alpine perennial wildflower, Polemonium viscosum. Measurements were made over 4 yr on 34 maternal sibships under natural conditions. A significant phenotypic cost of early reproduction characterized the study population. Plants that flowered after only one year's growth had twice as many leaves and 25% more shoots than nonflowering individuals of equal age. However, early flowering decreased leaf number by 18% in the subsequent year and survivorship by 20% after two years relative to changes in leaf number and survival of nonflowering plants. For such trade-offs to shape the further evolution of reproductive schedules, flowering probability and those age-specific components of plant size that represent the energetic currency for reproductive costs must be heritable. Although families showed significant heterogeneity in the probability of early flowering, most (62%) entirely failed to flower. Moreover, phenotypic variation in vegetative size components at ages 1 and 2 had little genetic basis. Only at ages 3 and 4, after vegetative and demographic costs of early reproduction had been incurred, did vegetative size components (leaf length and number, and shoot number) vary significantly among families. Results of this study provide little evidence of a genetically based trade-off between early reproduction and subsequent survival in P. viscosum.     

刺五加的有性生殖与营养繁殖

刺五加 Eleutherococcus senticosus (Rupr.et Maxim.)Maxim,既可进行有性繁殖,又可进行营养繁殖。本文报道其三类花丝长度不同的植株每个花序的花朵数量、座果率、饱满种子率及根茎形态和形态发生的某些特点。通过人工受精,检测了其繁育系统。结果表明:长花丝植株不座果,短花丝植株座果,但不同年份、不同生境中座果率不同,中花丝植株也座果但饱满种子率教低。在正常年份,短花丝植株的座果率接近40％,并且林缘的座果率稍高于皆伐迹地和次生林下的。考虑到中花丝植株在所研究地区居群数很少,我们认为绝大多数刺五加种子是异花传粉的产物,其有性生殖与营养繁殖相配合,在无人为破坏的前提下,该物种不应该濒危。     

植物有性生殖对大气CO2浓度变化响应的研究进展

 比较详细地概述了过去数十年关于在大气CO₂浓度升高条件下,植物有性生殖特性发生变化的主要研究成果。随着植物相对生长速率加快,植株达到有性生殖所需形体大小的时间变短,开花期提前,生殖器官的生物量也相应提高,其主要表现为开花数量、花粉和花蜜产量、果实数量与大小、种子大小与产量等均有不同程度的增加。对大多数农作物而言,种子产量的增加主要通过种子数量的增加,而与种子大小变化关系不大。通常,高浓度CO₂对豆科植物种子含氮量影响比较小, 却能显著地降低非豆科植物种子含氮量。不同类型植物的生殖生物量增加趋势存在一定的规律性,如不定型植物>定型植物,豆科植物>C₃非豆科植物>C₄植物,栽培植物>野生植物。针对国内外对CO₂浓度升高影响植物有性生殖特性的研究中存在的不足,该文提出了今后研究应该注意的问题。     

Optimal resource allocation to seeds and vegetative propagules under density-dependent regulation in Syneilesis palmata (Compositae)

Syneilesis palmata reproduces by both seeds and vegetative propagules (short rhizomes). The latter result in the production of new plants that are larger in size and hence have a higher survival probability and a higher growth rate than seeds. A previous study predicted that the optimal reproductive strategy, in terms of maximizing population growth rate (a fitness measure under no density regulations), was pure vegetative reproduction. However, high resource investment to vegetative propagules can cause local crowding resulting in reduced demographic performances of the plants, because the vegetative propagules of Syneilesis are produced close to one another. We examined, in this situation, the impact of allocating a certain proportion of reproductive resource to seeds with relatively greater capacity for dispersal. We simulated dynamics of hypothetical Syneilesis populations with various reproductive resource allocation balances (from pure seed to pure vegetative reproduction), using a density-dependent matrix model. In the model, it was assumed that plants from vegetative propagules experienced density-dependent reduction in their survival probabilities, but this was not the case for plants originating from seeds. Each allocation strategy was evaluated based on an equilibrium population density, a fitness measure under density-dependent regulations. The optimal reproductive strategy predicted was pure vegetative reproduction. Unrealistic conditions were required for seed reproduction to be favoured, such as the production of seeds one hundred times the normal number per unit resource investment. However, the conditions were fairly relaxed compared with those required in the model where no density effects were incorporated. This indicates that escape from local crowding is likely to be one of the roles of seed production in Syneilesis.     

养分供应对3种舞花姜属植物繁殖方式的影响

该研究选用的3种舞花姜属植物中,毛舞花姜(Globba barthei)和双翅舞花姜(G. schomburgkii)自然条件下开花不结实,以珠芽进行繁殖;异果舞花姜(G. racemosa)则同时以种子和珠芽进行繁殖。在人工栽培条件下,高养分处理显著增加毛舞花姜的珠芽干重((1.11±0.10) g vs. (3.08±0.69) g,p=0.010 7)、珠芽数量((30.58±2.92) vs. (74.74±9.73),p=0.000 4)、珠芽大小((10.5±1.48) mg vs. (53.50±11.42) mg,p=0.001 5)、植株营养体重((3.99±0.23) g vs. (9.67±1.17) g,p=0.000 2)和双翅舞花姜的珠芽数量((51.74±3.64) vs. (108.71±21.52),p=0.018 1)。不同养分条件下两种舞花姜的开花数量无显著差异。人工去除珠芽、花对两种舞花姜植株当年生花和珠芽的数量无显著影响(p<0.05)。自然条件下异果舞花姜不同居群间珠芽大小、珠芽数、珠芽重、果实重、种子数和营养体重等均存在极显著差异(p<0.001)。异果舞花姜各居群植株珠芽数和营养体重(r=0.901,p<0.05)、珠芽重和珠芽大小 (r=0.849,p<0.05) 呈显著正相关;果实重和种子数(r=0.998,p<0.05) 呈显著正相关。土壤因子主成分分析表明前3个主成分提供的信息量分别为50.575%、18.204% 和11.883%,其中第一主成分中的全氮(0.959)、速效氮(0.885)和有机质(0.821)负荷量最大,第二主成分中土壤速效磷(0.824)负荷量最大。植株营养体重和土壤速效磷极显著正相关(r=0.906,p<0.01),珠芽大小与全氮(r=0.798)、速效氮(r=0.780)和有机质(r=0.821)均呈显著正相关(p<0.05)。果实重和种子数与土壤因子相关性不显著(p<0.05)。3种舞花姜的无性繁殖器官更易受到养分供应的影响,有性繁殖器官对养分供应变化响应不显著,有性和无性繁殖之间似不存在补偿关系。     

THE RELATIVE CONTRIBUTIONS OF TIME AND EGGS TO THE COST OF REPRODUCTION

Whether the trade-off between current and future reproduction in insect parasitoids is mediated by the costs of time or eggs remains an issue of contention. Life-history models predict that parasitoids have some risk of exhausting their lifetime supply of oocytes. I develop a simple conceptual model that assesses the relative contributions of time and eggs to the cost of reproduction by placing them in a common currency: foregone future fitness returns. Although rates of egg limitation observed in nature are modest, eggs still often make the dominant contribution to the overall cost of oviposition. Therefore, models of parasitoid reproduction must recognize the costliness of both time and eggs.     

毛红椿天然种群有性繁殖适合度及其繁殖更新

以九连山国家自然保护区毛红椿4个天然种群为研究对象,于2006—2016年调查毛红椿有性繁殖和自然更新的情况,分析其繁殖适合度系数和个体水平适合度.结果表明:九连山毛红椿各地理种群结实单株的初始数量较少(3~9株),经70余年的繁衍发育,现存结实单株的数量仅2~10株,且来源于原始单株或子1~2代.不同种群间有性繁殖差异显著,但结实能力呈逐年下降的趋势;随群落发育成熟,土壤种子库保存与种子萌发的失利,导致能正常生长发育成熟的林木数量近乎为0.毛红椿最佳性成熟年龄为40年,早期优势明显,适合度系数早期快速增长,为2.0~2.8,但急剧减少至0.3~0.5,之后较平稳减速至近乎于0;种群间个体有性繁殖适合度(0~14株·cm2)存在较显著差异,但均较低,甚至低至0;以现有繁殖率计算,有性繁殖与更新的适合度实测值均远低于预估值.总之,受有性繁殖遗传适合度低的影响,不同种群间有性繁殖与更新能力趋同衰退;个体有性繁殖适合度进一步降低且面临更高的投资风险,现有繁殖体系因此失衡并趋于恶化.建议开展繁殖交配、授粉结实及遗传多样性评价研究,同时人为干预林分环境,于结实期清理林地枯落物,在幼苗至幼树生长过渡期适当疏伐.     

THE EFFECT OF NUCLEAR AND CYTOPLASMIC GENES ON FITNESS AND LOCAL ADAPTATION IN AN ANNUAL LEGUME,CHAMAECRISTA FASCICULATA

The role of nuclear genes in local adaptation has been well documented. However, the role of maternally inherited cytoplasmic genes to the evolution of natural populations has been relatively unstudied. To evaluate the contribution of cytoplasmic and nuclear genomes and their interactions to local adaptation we created second-generation backcross hybrids between a Maryland and an Illinois population of the annual legume Chamaecrista fasciculata. Backcross progeny were planted in the sites native to each population for two years and we quantified germination, survivorship, fruit production, vegetative biomass, and cumulative fitness. We found limited evidence for the contribution of either cytoplasmic or nuclear genes to local adaptation. In Maryland plants had greater survivorship, biomass, fruit production, and cumulative fitness if their nuclear genome was composed predominately of native Maryland genes; cytoplasmic genes did not affect fitness. In Illinois local cytoplasm marginally enhanced fitness, whereas Maryland nuclear genes outperformed local nuclear genes. Interactions between cytoplasmic and nuclear genes influenced seed weight, vegetative biomass, and fitness and therefore may affect evolution of these characters. Genetic effects were stronger acting through seed size than directly on characters. However, seed size differences between the two populations were largely genetic and therefore selection on fitness components is likely to result in evolutionary change. The contribution of nuclear and cytoplasmic genes to fitness components varied across sites and years, suggesting that experiments should be replicated and conducted under natural conditions to understand the influence of these genomes and their interactions to population differentiation.