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1.
真菌病毒是一类以真菌和卵菌为寄主,并在真菌和卵菌内完成生命周期的病毒类群,广泛存在于各真菌和卵菌类群中。部分病毒会导致其真菌寄主出现弱毒现象,从而降低病原真菌对植物的致病能力。目前,已在包括引致禾草叶斑病、褐斑病、赤霉病及豆科牧草根腐病在内的病原中发现了具弱毒特性的病毒,具有生防方面的利用价值。此外,近年来发现的真菌病... 相似文献
2.
禾草内生真菌是一个多样性十分丰富的微生物类群,因其具有重要的生理和生态作用而成为当前国内外研究的热点。禾草内生真菌的多样性主要有种的多样性、宿主多样性、生境多样性、形态多样性以及遗传多样性。主要是感染冷季型禾草的香烛菌属(Epichloё)及其无性态Neotyphodium属。全球生态环境复杂、宿主植物多样性丰富,导致内生真菌的多样性更加丰富,从而会发现更多新的真菌分类单元,这在菌种收集和保藏方面独具优势。内生真菌可使禾草提高抗逆性并适应逆境甚至极端环境条件,这对于深入探讨内生真菌-宿主之间的相互作用,有目的性和科学性地构建新的禾草内生真菌共生体及植物微生态系统的研究都具有十分重要的意义。 相似文献
3.
内生真菌对禾草类植物抗旱性的影响 总被引：4，自引：6，他引：4
综述了国内外近年来关于内生真菌Neotyphodium对禾草类植物抗旱性方面的研究成果。结果表明:与不带菌禾草相比,带菌禾草的抗逆性强、产量高,特别是内生真菌的侵染可增加宿主植物的抗旱性。据报道,内生真菌主要是通过促进植株根系发育、叶片生长、气孔开闭、渗透调节、抗氧化保护系统等来提高禾草类植物的抗干旱胁迫能力。但也有学者认为并非所有内生真菌对宿主禾草的抗旱性都有增益作用,内生真菌与禾草的共生关系还很大程度上决定于宿主、内生真菌基因型和生境的相互关系。在未来的研究中应以内生真菌-禾草共生体的抗旱机理、生物学特性和群体特征为重点;此外利用真菌-禾草共生体的抗旱特性开展优良牧草草坪草选育,发挥内生真菌在天然草地中的生态作用也是重要的研究方向。 相似文献
4.
M.R.Siegel 《草原与草坪》1988,(3)
本文作者通过对禾草内生真菌的研究,指出禾草—内生真菌的关系,集中反映了草原发生发展诸因素中,植物与微生物,植物与动物,微生物与动物之间的错综复杂的关系。一方面,真菌对禾草的侵染使草原畜牧业生产造成巨大的经济损失;另一方面,含真菌禾草的抗虫性、抗逆性增强,草地寿命延长。禾草内生真菌的双重特性,引起了国外专家们的专注,并取得了一定的进展。 相似文献
5.
内生真菌感染大部分禾草形成互惠共生体,提高共生体对环境适应性,并进而对动物、微生物以及整个生态系统产生广泛的影响,使该领域成为近年来研究的热点问题。分子生物学技术、基因组学、蛋白组学和代谢组学以及相应的信息生物学技术的应用加快了禾草内生真菌的研究,尤其是内生真菌全基因组序列的测定,明确了次生代谢物多样性及其与基因的关系,鉴定相关的功能基因和蛋白,基因敲除技术阐释了维持内生真菌与寄主动态平衡的分子机制。利用基因组学等技术筛选对家畜无毒的内生真菌菌株, 通过接种技术建立新的既具有抗逆性,又对家畜无毒的禾草-内生真菌共生体,提高禾草的品质并确保对动物的安全性,在牧草及草坪草育种上获得了巨大成功。但是内生真菌的寄主特异性限制了内生真菌可利用的范围,因此后续应继续利用基因组学和代谢组学新技术深入研究内生真菌与寄主相互作用的机制,利用基因工程技术人工创造无毒菌株,克服共生体创制的瓶颈。本研究旨在对以上内容进行综述,以期为更广泛利用内生真菌进行牧草和草坪草育种奠定基础。 相似文献
6.
禾草内生真菌(Epichloё属)是指在宿主禾草的组织间隙内完成其全部或大部分生命周期，但不引起宿主禾草产生外部明显症状的一类真菌。其作为重要的农业微生物资源，一方面能促进宿主植物的生长、提高宿主对不良环境的抵抗能力；另一方面，部分内生真菌与宿主形成的共生体所产生的部分生物碱可引致草食家畜中毒，影响草地畜牧业的健康发展。禾草内生真菌的这一双重特性已经成为国际草业领域近30年来的研究热点。本文首先综述了有性型和无性型Epichloё属禾草内生真菌的命名历史和分类现状，其次对我国目前已发现的禾草内生真菌资源及其分布以及禾草内生真菌在抗逆育种方面的研究进展进行归纳总结，最后针对禾草Epichloё属内生真菌的分类和应用进行了展望，以期为挖掘和利用有益禾草内生真菌资源、培育优良植物新品种、发展现代草地畜牧业和生态环境建设提供科学依据。 相似文献
7.
在温室盆栽条件下,以侵染内生真菌和未侵染内生真菌的黑麦草为材料,接种幼套球囊霉(Claroideoglomus etunicatum)和根内球囊霉(Rhizophagus intraradices)以及两种AM真菌的混合菌剂,通过比较单一及混合AM真菌和禾草内生真菌对黑麦草株高、根长、生物量、P含量、可溶性糖、可溶性蛋白以及光合指标等方面的差异,探究AM真菌与禾草内生真菌对黑麦草生长的影响。结果表明,接种幼套球囊霉、根内球囊霉和混合菌剂的黑麦草平均AM真菌侵染率分别为44.04%,34.13%和41.13%,禾草内生真菌降低AM真菌平均侵染率22.28%。接种AM真菌和侵染禾草内生真菌均提高了黑麦草形态和生理生化指标,且二者(尤其是幼套球囊霉与禾草内生真菌)共存时,黑麦草的形态和生理生化指标最高,与既不侵染禾草内生真菌也不接AM真菌的处理相比,幼套球囊霉与禾草内生真菌共同作用时总P含量、总生物量和净光和速率分别提高48.21%, 21.12%和73.53%,总可溶性糖和蛋白分别提高147.12%和24.27%。总体而言,AM真菌显著促进了植物地上、地下部分生长,而禾草内生真菌主要促进植物地上部分的生长。 相似文献
8.
丛枝菌根真菌(Arbuscular Mycorrhizal Fungi,AMF)、禾草内生真菌和植物病原菌广泛存在于农业生态系统中。AMF和禾草内生真菌均能与宿主植物形成共生体,促进宿主植物对养分、水分的吸收,提高植物对病害、干旱等生物和非生物逆境的抗性。植物病原菌引致的植物病害可降低植物产量和品质,造成生产上的重大损失。AMF可降低植物发病率和病情指数,其机理包括AMF与病原菌竞争侵染位点,养分和空间、消耗病原菌的能量、提高菌根植物对水分和养分的利用效率、调节病程相关蛋白。禾草内生真菌可通过分泌抑菌活性物质、诱导植物体产生抗性反应及减少病害介体的传播,提高植物地上生物量和抗病性。AMF和禾草内生真菌与其它微生物的互作因植物、真菌而异,有相互促进的效应,也有相互抑制的效应。研究和明确农业生态系统中三类微生物的互作机理,进而利用禾草内生真菌和AMF提高抗逆性及产量、防治病害,对于促进和维持农业生态系统可持续发展具有重要的意义。 相似文献
9.
鲍根生 《青海畜牧兽医杂志》2020,50(2)
冷季型禾草与Epichloё属内生真菌建立互利共生关系,提高禾草对生物和非生物逆境的耐受性,进而影响整个草地生态系统结构、功能和能量循环过程,成为植物共生微生物和宿主共生关系研究的焦点。本文从禾草内生真菌生活史、宿主共生关系协同进化、产生生物碱种类及功能、提高宿主抗逆性及与其他生物交互作用等方面进行系统阐述,揭示禾草内生真菌在草地生态系统中的作用,为挖掘内生真菌资源,探讨合理利用途径和生态功能以及草地畜牧业的健康与可持续发展提供理论依据。 相似文献
10.
在自然界中广泛存在真菌与植物形成的共生体,这种共生作用可以引起真菌和其寄主植物发生重要的适应性变化。内生真菌与冷季型草坪草高羊茅和黑麦草形成互惠共生体,与病原真菌生长方式的不同,内生真菌仅在寄主细胞间生存,与寄主保持协同生长,这些独特的生长方式使得内生真菌生活在植物特定组织内,从不侵染植物细胞,因而寄主缺乏防御反应,二者通过信号交流和调控建立并维持这种互惠共生关系。内生真菌和寄主信号交流包括了多种已知的途径,其中确定的有活性氧调控途径,有丝分裂原活化蛋白(mitogen-activated protein,MAP) 激酶级联信号途径及cAMP和Ca2+作为第二信使的信号途径,本文综述了通过显微镜等各种技术确定的内生真菌在寄主细胞间的生长方式和目前通过基因敲除技术已知的与维持内生真菌与寄主互惠共生相关的基因,期望为深入揭示内生真菌与寄主的信号转导途径提供参考。 相似文献
11.
Waller PJ 《New Zealand veterinary journal》1992,40(1):1-3
Control of nematode parasites in ruminants is directed almost exclusively at the parasitic stage in the host using conventional anthelmintic therapy. However, to complete their life cycle, parasites have to develop through a series of free-living stages on pasture. It is within this environment that there is a vast range of cohabiting micro-organisms, some of which are known to infect or prey on nematodes. These include bacteria, protozoa, viruses and fungi. To date, most interest has been focused on those organisms producing chemical toxins which have been developed as anthelmintics, e.g. Streptomyces/avermectins. Yet the potential of predacious and nematoxic fungi and bacteria for the biological control of nematode parasites of livestock remains largely untapped. These organisms may well offer a cheaper and more sustainable approach to reducing the impact of parasitism in livestock. 相似文献
12.
Innes EA Bartley PM Rocchi M Benavidas-Silvan J Burrells A Hotchkiss E Chianini F Canton G Katzer F 《Veterinary parasitology》2011,180(1-2):155-163
Protozoan parasites are among some of the most successful organisms worldwide, being able to live and multiply within a very wide range of hosts. The diseases caused by these parasites cause significant production losses in the livestock sector involving reproductive failure, impaired weight gain, contaminated meat, reduced milk yields and in severe cases, loss of the animal. In addition, some protozoan parasites affecting livestock such as Toxoplasma gondii and Cryptosporidium parvum may also be transmitted to humans where they can cause serious disease. Data derived from experimental models of infection in ruminant species enables the study of the interactions between parasite and host. How the parasite initiates infection, becomes established and multiplies within the host and the critical pathways that may lead to a disease outcome are all important to enable the rational design of appropriate intervention strategies. Once the parasites invade the hosts they induce both innate and adaptive immune responses and the induction and function of these immune responses are critical in determining the outcome of the infection. Vaccines offer green solutions to control disease as they are sustainable, reducing reliance on pharmacological drugs and pesticides. The use of vaccines has multiple benefits such as improving animal health and welfare by controlling animal infections and infestations; improving public health by controlling zoonoses and food borne pathogens in animals; solving problems associated with resistance to acaricides, antibiotics and anthelmintics; keeping animals and the environment free of chemical residues and maintaining biodiversity. All of these attributes should lead to improved sustainability of animal production and economic benefit. Using different protozoan parasitic diseases as examples this paper will discuss various approaches used to develop vaccines to protect against disease in livestock and discuss the relative merits of using live versus killed vaccine preparations. A range of different vaccination targets and strategies will be discussed to help protect against: acute disease, congenital infection and abortion, persistence of zoonotic pathogens in tissues of food animals and passive transfer of immunity to neonates. 相似文献
13.
Miodrag Ristic 《Veterinary parasitology》1976,2(1):31-47
Rickettsiaea and protozoa which invade circulating leukocytes and erythrocytes are discussed in this communication. Characteristic features of animal diseases caused by these agents are (1) they are transmitted by arthropod vectors, (b) most cause devastating losses to the livestock industry, and (c) some are important to human health. A common characteristic of blood protista is their ability to survive for a long time in immunologically hostile hosts. This can be attributed to their intracellular domicile, possible incorporation of host cell proteins in their structure, and antigenic variations causing evasion of the host's surveillance mechanism. The last decade has seen an expansion in the application of immunologic principles to the study of blood protista. Infections caused by blood protista stimulate humoral and cell-mediated immune responses. Antibodies have been measured in serodiagnostic procedures. Cell-mediated immunity in combination with antibodies of various activities seem to be the main protective mechanism. A vaccine using a live attenuated agent (Anaplasma marginale) which induces and maintains the above responses constitutes a novel, realistic, and practical approach to control of blood protistan diseases. 相似文献
14.
Frank DN 《Journal of animal science》2011,89(3):835-844
The priorities of public health and agricultural sciences intersect through a shared objective to foster better human health. Enhancements in food quality and reductions in the environmental effects of modern agriculture represent 2 distinct paths through which animal sciences can contribute to the cause of public health. Recent developments in the study of human-associated microbial communities (microbiotas), notably in association with disease, indicate that better understanding of the microbial ecology of livestock can contribute to achieving the goals of better foods and a cleaner environment. Culture-independent microbiological technologies now permit comprehensive study of complex microbial communities in their natural environments. Microbiotas associated with both humans and animals provide myriad beneficial services to their hosts that, if lost or diminished, could compromise host health. Dysfunctional microbial communities have been noted in several human conditions, including inflammatory bowel disease, obesity, and antibiotic-associated diarrhea. Examination of the mechanisms by which the human microbiota influences health and disease susceptibility can inform similar studies of host-microbe function in the animal sciences. Insights gained from human studies indicate strategies to raise not only healthier livestock, through selective manipulation of microbial communities, but also healthier humans. 相似文献
15.
从最初发现黑麦草(Lolium perenne)和高羊茅(Festuca arundinacea)引起家畜中毒到后来其携带的内生真菌被发现,以及进一步的研究证实,内生真菌的存在不但导致家畜中毒而且能显著提高宿主在群落中的竞争力,也因禾草内生真菌的这种重要生理和生态作用,使其逐步成为国内外研究的热点之一,这也给内生真菌检测技术的发展提供了契机。初期主要是借鉴病原真菌等微生物检测的一些较成熟的方法,对禾草内生真菌进行染色镜检或分离检测,但容易受宿主种类、物候期、检测部位等因素的影响,造成检测结果的不准确。随着分子生物学、遗传学等学科的快速发展,酶联免疫吸附测定法(enzyme linked immunosorbent assay,ELISA)、聚合酶链式反应法(polymerase chain reaction,PCR)、实时荧光PCR法(realtime PCR)等现代分子技术在禾草内生真菌方面的应用和改进,使得内生真菌的检测方法不断推陈出新,这些方法能在一定程度上对传统检测方法给予有效的补充。快速有效的确定禾草内生真菌的存在、分布规律、分类地位等,需要准确合理地选择特异性较强的检测方法,例如定性或定量检测,并结合经典的染色镜检和分离法对禾草内生真菌进行确定。本研究对以上内容进行了综述,以期更深层次的借鉴和发展关于其它微生物的经典检测方法,同时开发具有禾草内生真菌特异性的检测技术,这些技术不仅能够鉴定内生真菌存在与否,而且能对内生真菌进行定量和活性的检测,是发展的重要方向和热点。对内生真菌定性、定量和活性的检测是未来值得研究的重点。 相似文献
16.
镰刀菌(Fusarium spp.)是多种重要农作物的病原体,不仅可造成农作物产量和品质的严重损失还可在离体培养条件下或植物寄主体内产生一系列被称为镰刀菌毒素的次生代谢产物。这些毒素一方面作为致病因子与镰刀菌对宿主植物的致病力密切相关,另一方面可导致家畜生产性能下降和相关病症的出现,进而影响农业生态系统并对人类健康造成威胁。鉴于镰刀菌毒素对农作物生产的影响及其对家畜和人类的毒性作用,目前已有较多关于镰刀菌侵染粮食作物后产生毒素种类的研究,但关于镰刀菌侵染豆科牧草后产生的毒素种类以及毒素在镰刀菌对豆科牧草致病力方面作用的研究则较少。本文对引起主要粮食和饲料作物病害的常见镰刀菌物种产生的主要毒素,以及这些毒素对植物、家畜和人类的危害进行了综述,并对豆科牧草中镰刀菌毒素的研究前景及意义进行了展望。 相似文献
17.
Maud VP Charron Georgette Kluiters Michel Langlais Henri Seegers Matthew Baylis Pauline Ezanno 《Veterinary research》2013,44(1):44
Bluetongue (BT) can cause severe livestock losses and large direct and indirect costs for farmers. To propose targeted control strategies as alternative to massive vaccination, there is a need to better understand how BT virus spread in space and time according to local characteristics of host and vector populations. Our objective was to assess, using a modelling approach, how spatiotemporal heterogeneities in abundance and distribution of hosts and vectors impact the occurrence and amplitude of local and regional BT epidemics. We built a reaction–diffusion model accounting for the seasonality in vector abundance and the active dispersal of vectors. Because of the scale chosen, and movement restrictions imposed during epidemics, host movements and wind-induced passive vector movements were neglected. Four levels of complexity were addressed using a theoretical approach, from a homogeneous to a heterogeneous environment in abundance and distribution of hosts and vectors. These scenarios were illustrated using data on abundance and distribution of hosts and vectors in a real geographical area. We have shown that local epidemics can occur earlier and be larger in scale far from the primary case rather than close to it. Moreover, spatial heterogeneities in hosts and vectors delay the epidemic peak and decrease the infection prevalence. The results obtained on a real area confirmed those obtained on a theoretical domain. Although developed to represent BTV spatiotemporal spread, our model can be used to study other vector-borne diseases of animals with a local to regional spread by vector diffusion. 相似文献
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Siembieda JL Kock RA McCracken TA Newman SH 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2011,12(1):95-111
This paper identifies some of the more important diseases at the wildlife-livestock interface and the role wildlife plays in disease transmission. Domestic livestock, wildlife and humans share many similar pathogens. Pathogens of wild or domestic animal origin that can cause infections in humans are known as zoonotic organisms and the converse are termed as anthroponotic organisms. Seventy-seven percent of livestock pathogens and 91% of domestic carnivore pathogens are known to infect multiple hosts, including wildlife. Understanding this group of pathogens is critical to public health safety, because they infect a wide range of hosts and are most likely to emerge as novel causes of infection in humans and domestic animals. Diseases at the wildlife-livestock interface, particularly those that are zoonotic, must be an area of focus for public health programs and surveillance for emerging infectious diseases. Additionally, understanding wildlife and their role is a vital part of understanding the epidemiology and ecology of diseases. To do this, a multi-faceted approach combining capacity building and training, wildlife disease surveillance, wildlife-livestock interface and disease ecology studies, data and information sharing and outbreak investigation are needed. 相似文献