共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
了解杜鹃(Cuculus spp.)对不同宿主鸟类的巢寄生,是研究杜鹃与其宿主之间协同进化的重要基础资料。大杜鹃(Cuculus canorus)和家燕(Hirundo rustica)分布遍及全国,且为同域分布,但两者之间的寄生现象尚未有过系统调查。2012年和2014年4~8月,对繁殖于吉林市昌邑区桦皮厂镇(34°58′44.18″N,126°13′26.83″E,海拔184 m)和海南岛的家燕种群进行调查,结果表明,吉林市昌邑区桦皮厂镇家燕种群的寄生率为2.4%(1/42),而在海南岛所调查的1 719个家燕巢未发现杜鹃寄生现象。同时在网络上搜集家燕巢寄生的报道案例,共记录到13巢家燕被大杜鹃寄生繁殖,均发生在北方的家燕种群。 相似文献
4.
不同寄主来源寄生疫霉菌株的遗传变异分析 总被引:5,自引:0,他引:5
从300条RAPD随机引物中筛选出扩增多态性丰富的13条引物,对寄主来源不同的29个寄生疫霉(Phytophthora parasitica)菌株进行基因组DNA遗传变异分析。用筛选出的13条引物对供试菌株进行RAPD-PCR扩增,共产生139条RAPD条带,其中133条为多态性条带,多态检测率为95.7%。利用PopGene Version 1.31软件对供试菌株间的遗传距离进行聚类分析并构建系统树状图,供试29个菌株被划分为5个遗传聚类组,不同菌株间具有丰富的遗传变异。其中寄主为烟草(Nicotiana spp.)、腊梅(Chimonanthus praecox)、凤尾兰(Yucca gloriosa)和西番莲(Passiflora edulis)的菌株的遗传结构与其寄主来源具有明显的相关性,而寄主为刺槐(Sophora chinensis)和番茄(Lycopersicum esculentum)的菌株与其寄主来源的相关性较小,来源于不同寄主植物的菌株之间遗传距离较远。结果提示在寄生疫霉与其不同寄主植物的长期协同进化过程中,寄主对病原菌的遗传结构具有一定的影响。 相似文献
5.
6.
真核生物的线粒体一般具有一定的典型的结构和功能。然而,在单细胞的寄生原生动物中却不断发现从数量、结构到功能均与典型线粒体明显不同的线粒体,表现出线粒体的巨大可塑性和丰富的多样性。该文对寄生原生动物中这些多样的线粒体进行了概述,并对形成这种多样性的根本原因,即这些生物对寄生生活微氧或无氧环境线粒体所发生的种种适应性进化进行了分析探讨。 相似文献
7.
在种子传播过程中动植物是否存在协同进化关系一直是争论的焦点。有观点认为,植物通过食果动物对其种子的传播可能获得逃避种子捕食者、占据新的生境斑块和基因流动等好处,而动物通过消化果肉获得营养和能量作为回报,动植物彼此相互作用,进而可能建立协同进化关系。动植物之间还可能发生在种、属或科水平以上的多物种的多配协同进化,或者通过关键种的协同进化来带动其他食果动物和植物相关性状的进化。“果肉防御假说”则认为果肉原本是保护种子的防御组织,后来才进化成为吸引食果动物以促进种子传播的物质。然而,食果动物和植物一对一的协同进化的例证并不多见;适合种子萌发和生长的环境在时空上难以确定;食果动物和植物的进化速度不一致;植物与种子传播者的选择压力存在着高度的不对称和不平衡,加上环境因素的重要影响,这种选择压力受到极大的限制而有可能变得不显著。种子传播中动植物在进化意义上的关系尚需进一步研究。未来研究应对食果动物和植物关系的复杂性和多样性有足够的认识。通过对系统发育中相联系的不同种的动植物关系的比较研究来揭示动植物关系对物种分化的影响,有可能为检验食果动物和植物之间的协同进化关系提供新的证据。食果动物传播种子对植物群落动态变化的影响、动植物关系和生物多样性保护等仍将是该领域研究的热点。 相似文献
8.
动物与植物种子更新的关系I.对象,方法及意义 总被引:7,自引:0,他引:7
大多数植物靠种子库来更新。种子从离开母体到建成幼苗的过程中始终受动物活动的影响。动物对种子既有取食消耗的不利一面,又有将其扩散到适于发芽的安全地点的有利一面,二者处于一种利弊权衡状态。研究动物与植物种子更新的关系,有助于揭示种群动态的机制,理解动物和植物之间协同进化的规律,了解生态系统演替及其组分之间的关系,认识取食种子的动物在生态系统中的作用,进而为生态系统维持和生物多样性保护提供科学依据及有效 相似文献
9.
拟寄生昆虫中的过寄生现象 总被引:2,自引:0,他引:2
对拟寄生昆虫同种过寄生现象做了综述。拟寄生昆虫的认识能力和寄生经历、其与寄主数量的相对比例、寄主的大小及两次被寄生的时间间隔等是导致过寄生是否出现的主要因素。过寄生常导致拟寄生昆虫发育历期延长、存活率下降、个体变小、子代雌性比降低。试验研究和大量饲养中应采取措施避免过寄生。 相似文献
11.
12.
13.
14.
15.
Molecular techniques have dramatically advanced our knowledge of the mechanisms that regulate appetite and body weight, yet human obesity, a significant healthcare problem, still lacks an effective science-based treatment. Infectious agents, including worm parasites, seem capable of overwhelming these regulatory systems. Can the study of parasites extend our understanding of what makes animals feed? 相似文献
16.
17.
18.
Jovani R 《Trends in parasitology》2003,19(1):15-6; author reply 16-7
19.
Andrew D. Sweet Sarah E. Bush Daniel R. Gustafsson Julie M. Allen Emily DiBlasi Heather R. Skeen Jason D. Weckstein Kevin P. Johnson 《International journal for parasitology》2018,48(8):641-648
Comparisons of host and parasite phylogenies often show varying degrees of phylogenetic congruence. However, few studies have rigorously explored the factors driving this variation. Multiple factors such as host or parasite morphology may govern the degree of phylogenetic congruence. An ideal analysis for understanding the factors correlated with congruence would focus on a diverse host–parasite system for increased variation and statistical power. In this study, we focused on the Brueelia-complex, a diverse and widespread group of feather lice that primarily parasitise songbirds. We generated a molecular phylogeny of the lice and compared this tree with a phylogeny of their avian hosts. We also tested for the contribution of each host–parasite association to the overall congruence. The two trees overall were significantly congruent, but the contribution of individual associations to this congruence varied. To understand this variation, we developed a novel approach to test whether host, parasite or biogeographic factors were statistically associated with patterns of congruence. Both host plumage dimorphism and parasite ecomorphology were associated with patterns of congruence, whereas host body size, other plumage traits and biogeography were not. Our results lay the framework for future studies to further elucidate how these factors influence the process of host–parasite coevolution. 相似文献
20.
D Atkinson 《Journal of theoretical biology》1991,150(2):251-260
Hamilton & Zuk (1982, Science 218, 384-387.) produced a model of sexual selection in which coevolutionary cycles of host and parasites generate consistently positive correlations between parent and offspring viability, and that animals choose mates for genetic disease resistance by scrutinizing characters whose full expression is dependent on health and vigour. They predicted a positive correlation between sexual showiness and parasite burden across species, and a negative correlation within a species. First, recent suggestions that interspecific correlations in the opposite direction to that indicated above are consistent with the mechanisms of Hamilton & Zuk's model are discussed. Second, it is shown that the model's predictions can be produced by heritable variation maintained by non-parasite fluctuating selection. In this case, the parasites associated with degree of sexual showiness are those able to amplify any initial heritable differences in vigour. Alternative sources of positive correlation between parent and offspring viability, which include the indirect effects of climatic change and exclude the need for host-parasite coevolutionary cycles, are also proposed. 相似文献