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长石莼(缘管浒苔)生活史的初步研究 总被引:3,自引:1,他引:2
摘要: 通过实验室培养观察,发现缘管浒苔的生活史包括单性生殖、无性生殖和有性生殖三种方式。单株培养时,发现有些配子体通过放散两鞭毛的配子完成单性生殖;有些孢子体通过放散两鞭毛或四鞭毛的中性游孢子进行无性生殖。同时,有性生殖则由配子体和孢子体相互交替完成;多株培养时,雌雄异体的配子体成熟后,分别放散两鞭毛的雌雄配子,雌雄配子接合成合子,合子进一步发育成孢子体,孢子体成熟后放散四鞭毛的游孢子,游孢子运动一段时间后固着,随后发育成配子体。缘管浒苔的生活史是单倍的配子体与二倍的孢子体相互交替的同形世代交替。在缘管浒苔的生活史中,无性生殖和单性生殖占有优势。因为不论是在无性生殖过程中的游孢子还是单性生殖过程中的配子,一经附着即可生长,无须经过有性生殖雌雄配子的接合过程,这就缩短了繁殖周期,加之配子囊和孢子囊放散配子和孢子的数量很大,在海况条件适宜的情况下,使缘管浒苔大量繁殖,从而可能成为“绿潮”的成因之一。 相似文献
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利用透射电镜技术研究了梭子蟹肌孢虫在三疣梭子蟹体内的组织分布和形式特点,结果显示,梭子蟹肌孢虫主要寄生在骨骼肌、血淋巴、鳃、胃和肠,而在心脏、肝胰腺、性腺和神经等部位未发现。在胃和肠的结缔组织以及骨骼肌中发现梭子蟹肌孢虫的分裂体,表明其可以在这些组织的细胞中增殖,尤其是在骨骼肌细胞中,大量不同发育时期的虫体显示了该虫对骨骼肌的亲嗜性。梭子蟹肌孢虫的分裂体以及其他增殖期的细胞仅寄生于宿主细胞内,而成熟的孢子可存在于宿主细胞内和细胞外基质中。梭子蟹肌孢虫的孢子有6种存在形式,在宿主细胞内和宿主细胞外基质中各有3种。孢子在宿主细胞内的存在形式:1孢子直接寄生于宿主细胞质中,自由游离,无膜包围;2孢子被单层膜包围,类微绒毛样突起物部分溶解,这种情况见于专业性吞噬细胞——无颗粒细胞内;3孢子被层状环形膜结构包围,类微绒毛样突起物清晰,这种情况见于非专业性吞噬细胞内。孢子在宿主细胞外基质中的存在形式:1孢子自由游离,无膜包围,类微绒毛样突起物清晰;2多个孢子被体液性被囊包围,类微绒毛样突起物清晰;3孢子无膜包围,孢外壁与类微绒毛样突起物消失。本研究阐明了梭子蟹肌孢虫在三疣梭子蟹体内的组织分布和孢子的存在形式,为进一步研究微孢子虫在宿主蟹体内的迁移规律提供了重要的基础数据。 相似文献
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通过实验室培养观察,发现Ulva linza的生活史包括单性生殖、无性生殖和有性生殖三种方式.单株培养时,发现有些配子体通过放散两鞭毛的配子完成单性生殖;有些孢子体通过放散两鞭毛或四鞭毛的中性游孢子进行无性生殖.同时,有性生殖则由配子体和孢子体相互交替完成;多株培养时,雌雄异体的配子体成熟后,分别放散两鞭毛的雌雄配子,雌雄配子接合成合子,合子进一步发育成孢子体,孢子体成熟后放散四鞭毛的游孢子,游孢子运动一段时间后固着,随后发育成配子体.Ulva linza的生活史是单倍的配子体与二倍的孢子体相互交替的同形世代交替.在Ulva linza的生活史中,无性生殖和单性生殖占有优势.因为不论是在无性生殖过程中的游孢子还是单性生殖过程中的配子,一经附着即可生长,无须经过有性生殖雌雄配子的接合过程,这就缩短了繁殖周期,加之配子囊和孢子囊放散配子和孢子的数量很大,在海况条件适宜的情况下,使Ulva linza大量繁殖,从而可能成为"绿潮"的成因之一. 相似文献
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D Haack 《Tier?rztliche Praxis》1987,15(3):269-273
For the inoculation of the dermatophyte-test-medium Fungassay, 200 skin scrapings from horses, 13 from cattle and 13 from artificially infected guinea pigs were used. As control methods, the alkali method, the fluorescent microscope technique and the usual mycological culture were available. For the analysis of skin scrapings, the Fungassay culture mediums are clearly inferior to the usual mycological culture. Fewer dermatophytes were isolated and false positive as well as false negative results occurred. The cultivation of Trichophyton verrucosum failed on the dermatophyte-test-medium. 相似文献
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生物发酵床养猪的利与弊 总被引:4,自引:0,他引:4
生物发酵床养猪技术的出现和推广,改变了现有的养猪模式,在一些科学试验及实际生产中得出了高效益、低污染、省劳力等结论,同样也出现了费时、费力、高成本等说法。发酵床养猪在广大养殖户心中仍然存在不少的阴影或者疑问,围绕着其利与弊产生了一场争论,本文将利用所获得的资料对生物发酵床养猪技术进行论述。 相似文献
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报道规模化猪场爆发PCV-2的病例。重庆忠县某猪场有经产母猪88头,断奶仔猪182头。2007年以来,坚持自繁自养,猪场稳定,猪只健康,全场发病率(包括仔猪)小于3%,死亡率低于1%。2009年4月,该场开展对外免费授精服务,9月3日种公猪发病,1周后断奶猪发病,病死猪血清和淋巴结中PCR检测PCV-2阳性。病死猪脾脏和淋巴结为病料制成灭活苗,全场紧急接种,并配合药物治疗,至10月底病势得以控制,统计本次发病,断奶猪发病86头,发病率为47.3%,死46头,死亡率为25.3%,种公猪发病后治愈。 相似文献
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论文旨在从进出口量、额和均价的角度,理清中、韩牡蛎进出口贸易的变动趋势。研究结果显示:1992-2011年,中国牡蛎进口贸易前期(1992-2006)波动上升,其后下降(2006-2008)再上升(2008-2011),进口价格震荡上升;1984-2011年,出口贸易在2000-2005年呈现明显高峰,出口价格有波动,但1998-2007年长期处于低谷;1976-2011年,韩国牡蛎进口贸易1993年开始急速上升,至1997年达到峰值,1998年又急速下降,其他时间虽有波动但相对稳定;出口贸易以2000年为界,此前波动上升,其后波动下降;牡蛎出口价格呈现上升(1984-1995)下降(1995-2002)再回升(2002-2011)的变动趋势;两国牡蛎进出口贸易自2008年前后均有上升迹象。 相似文献
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检测猪肺炎支原体抗体间接ELISA方法与单抗阻断ELISA方法的对比试验 总被引:2,自引:0,他引:2
猪肺炎支原体(Mycoplasma hyopneumoniae,Mhp)是猪地方性肺炎(Swine Enzootic Pneumonia,SEP)(亦称猪气喘病)的病原体。此病分布广,发病率高,自身致死率不高。由于Mhp能够破坏呼吸道黏膜-纤毛屏障,从而继发其他致病菌的感染,提高致死率。由于早期检测的困难和缺乏有效的药物,在疾病控制方面至今未能达到满意的效果。本实验以Mhp168株为材料,研制出其特异性单克隆抗体,并利用Mhp的全菌蛋白作为包被抗原建立了间接ELISA方法,且证明有一定的实用性。 相似文献
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Adsorption of the mycotoxin ochratoxin A by activated charcoal, various bentonites (acid, alkaline, neutral), and hydrated sodium calcium aluminosilicate was tested in vitro as well as in feeding experiments with pigs. In vitro tests showed that the 1% addition of activated charcoal leads to complete adsorption of ochratoxin A from aqueous solutions. This effect was not influenced by pH-values ranging from 3-8. In contrast, adsorption by bentonite and hydrated sodium calcium aluminosilicate occurred primarily in the acid range (pH 3-4). Dietary addition of hydrated sodium calcium aluminosilicate (1%) and acid bentonite (1%, 10%) to ochratoxin A-contaminated feed (1.0 mg/kg) had no effect on the blood or tissue levels of the toxin in pigs. The addition of 1% activated charcoal caused a slight decrease of ochratoxin A in the blood, whereas a tenfold dosage resulted in a 50% to 80% reduction of ochratoxin A levels in both blood and tissue. Reduction of ochratoxin A absorption via the dietary administration of activated charcoal (5%) was confirmed in a 16 week feeding experiment. However, this experiment also showed the serum level of vitamin E to be lower than in the controls receiving adsorbent-free feed. 相似文献
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A Mayr 《Tier?rztliche Praxis》1986,14(2):237-244
The fundamentals of paramunization are briefly discussed to provide better understanding of paramunization of pigs. Veterinary practice and experimental studies demonstrate the usefulness, efficacy and harmlessness of paramunization of pigs. Mortality, morbidity as well as weight gain in piglets are used to evaluate the effect of the inducers PIND-AVI and/or PIND-ORF on piglets which have been treated shortly after birth. The therapeutic effect of paramunization has been studied in herds with enzootic pneumonia. Paramunization is especially suitable in stimulating the immune system, in treating immune deficiencies, in the prophylaxis of the stress syndrome (e.g. induced by transport, weaning, changing stalls, etc.) and in treating pluricausal, multifactorial infectious diseases such as enzootic pneumonia, rhinitis atrophicans, "crowding" disease. Paramunization of pigs is discussed, using PIND-ORF as an example of a biological inducer. Paramunization as a biological method to stimulate immunity provides a new concept of prophylaxis and therapy opposed to the uncontrolled use of chemicals in pig production. 相似文献
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猪囊尾蚴病是猪带绦虫的幼虫引起人、畜共患的寄生虫病。它严重影响养猪事业的发展,使畜牧业造成重大经济损失,给人民身体健康和生命带来严重威胁。为有效控制和消灭猪囊尾蚴病,维护人民的生命和财产安全,笔者通过对病原特性、传播方式和主要危害进行浅析,归纳出一套有效的防治措施,给猪囊尾蚴病的防治提供参考。 相似文献
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水产种业是水产养殖业的战略性、基础性核心产业,水产苗种引进是促进水产养殖业绿色发展的一个重要途径。中国水产苗种引进品种繁多,水产观赏动物成为新宠,通过分析2013—2018年水产苗种进口贸易数据,其主要特征为:进口额呈下降趋势,进口种类涉及24种,部分种类的进口频率达到100%,用于水产养殖的苗种和受精鱼卵进口额分别为14061.19×104美元和632.02×104美元。从进口额数据来看,小虾及对虾、鳗鱼、受精鱼卵及其他鱼种等主要进口苗种种类对水产养殖业发展的影响较大,其中鳗鱼增养殖业对进口鳗苗的依赖程度较高,平均依赖度为50.86%。提出构建养殖鱼类苗种进口预警机制,谋划养殖鱼类品种的替代策略,提高对虾苗种控制能力,做好水产苗种进口质量安全防范等建议,以保障水产养殖产业健康稳定发展。 相似文献
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The "Reflotron" system (Boehringer Mannheim) was compared with standard laboratory methods for determination of blood values, e.g. haemoglobin, glucose, urea, ASAT/GOT and GGT in pigs and sheep. Various different commercial control sera as well as blood and plasma samples from pigs and sheep were used for evaluation of its precision. The day-to-day precision of all parameters was satisfactory. The accuracy of the values was tested in 56(48) blood samples of healthy and sick pigs (sheep) by using standard substances (glucose, urea) and by comparing them with values measured by standard laboratory methods. There were systematic differences between "Reflotron" and other values in the glucose- and enzyme-values, which can be corrected with the help of conversion factors. In pigs, the enzyme GGT can not be determined accurately with the "Reflotron" system. 相似文献