根瘤菌-豆科植物共生多样性与地理环境的关系

根瘤菌与豆科植物形成的根瘤或茎瘤固氮共生体系在农、林、牧业的可持续发展中具有重要作用。 10 0多年前 ,在根瘤菌研究的起始阶段 ,人们提出的“宿主专一性”及“互接种族”2个概念一直流传至今。 2 0世纪 4 0年代 ,有学者根据实验室内豆科植物的交叉结瘤结果否定过“互接种族”的观念 ,70～ 80年代又发现某些根瘤菌在实验室条件下有广谱共生现象。但根瘤菌与豆科植物共生体与地理环境的关系却很少被涉及过。本文在对大量根瘤菌进行分类研究的基础上 ,结合宿主植物及其区域地理环境的综合分析 ,揭示出根瘤菌与豆科植物的共生关系因其所处的区域地理环境不同而具多样性 ,并指出豆科植物根瘤菌接种剂的筛选和应用必须考虑菌株对当地环境的适应能力。

豆科植物—根瘤菌识别的分子机制及其共生多样性与生态环境的关系

豆科植物—根瘤菌的相互识别属亲和性(阴性)识别系统,吸附的专化性取决于分子识别,参与分子识别的物质包括豆科植物凝集素、类黄酮和根瘤菌表面的胞外多糖、荚膜多糖及脂多糖。介绍了这些识别子的研究进展及豆科植物—根瘤菌相互识别的分子机制,并揭示豆科植物—根瘤菌共生多样性与生态环境的关系。

满江红鱼腥藻与其宿主的遗传多样性和协同性的RAPD分析

从 16个代表不同种属或地域来源的满江红样本中分离出共生藻并通过处理获得无藻的满江红宿主 ,对二者同步进行了RAPD扩增 ,分别得到了大量DNA多态片段。通过建立满江红鱼腥藻及其宿主的UPGMA聚类关系图 ,看出二者在遗传分支上存在着一定程度的协同对应关系。但在种内的不同品系间 ,这种协同性有所减少 ,发现有的品系的共生藻发生了明显的变异。

微生物与植物共生关系的研究及其利用

共生是生物适应环境的一种必然现象,存在各种各样的自然组合,包括微生物之间的共生,细菌、放线菌、蓝细菌、真菌与植物共生等。生物多样性共生资源的发掘与利用在理论与实践上均有重要意义。

草间钻头蛛共生菌多样性测定及沃尔巴克氏体感染对宿主发育历期和性比的影响

为了解草间钻头蛛Hylyphantes graminicola体内共生菌的组成及共生菌对宿主的影响,通过高通量测序技术确定其体内的优势共生菌,采用常规PCR法对草间钻头蛛进行优势共生菌的感染检测,并研究了优势共生菌感染对草间钻头蛛子代的发育历期和性比的影响。结果表明:经高通量测序细菌16S r DNA的V3、V4区,确定草间钻头蛛的优势共生菌为沃尔巴克氏体Wolbachia和Cardinium。167头被检测蜘蛛中,Cardinium的感染率为100.00%,沃尔巴克氏体的感染率为38.92%。感染沃尔巴克氏体的草间钻头蛛F1代雌蛛的2龄期、3龄期、4龄期和总历期均极显著低于未感染的草间钻头蛛,感染沃尔巴克氏体的草间钻头蛛F1代雌蛛1龄期显著低于未感染的F1代个体,感染和未感染沃尔巴克氏体的草间钻头蛛F1代雌蛛的卵期和5龄期均无显著差异。感染沃尔巴克氏体后,草间钻头蛛F1代雄蛛的1龄期和总历期极显著缩短,2龄期、3龄期和5龄期显著缩短,而卵期和4龄期与未感染沃尔巴克氏体的F1代雄蛛之间无显著差异。另外,沃尔巴克氏体感染极显著提高了草间钻头蛛的子代性比。

An overview on the protected area system for forest conservation in Bangladesh

A total of 19 protected areas （PAs） have been established in Bangladesh representing all the four forest types of the country. Apart from being the repository of biological diversity, these PAs serve as the source of subsistence livelihoods to the local communities. While all the PAs are managed by the state Forest Department （FD）, with a view to ensure sustainability, a recent approach of co-management has been initiated in five PAs as a pilot project with an aid of development partners incorporating stakeholders＇ participation. Along with demonstrating a number of upbeat impacts, the initiatives exert some constraints which need to be addressed properly to ensure the success of participatory approach and enhance the ongoing conservation scheme. This paper reviews the published works, government and project documents to analyze the present status of PAs and suggest recommendations accordingly.

Hurricane Matthew Impacts to Marine and Coastal Biodiversity on Southern Coast of Dominican Republic

A rapid environmental assessment was conducted by the staff of Marine Biology Research Center （CIBIMA）, Faculty of Sciences, Universidad Aut6noma de Santo Domingo （UASD） on the southern coast of the Dominican Republic, to evaluate the effects of the hurricane Matthew on October 3, being the 14th storm of the year 2016 for the Caribbean region. The observations were carried out two weeks after the storm hit. These observations included coastal ecosystems, such as marshes, beaches, lagoons, wetlands, mangrove forests, nearshore sea grasses and coral reefs. The evaluation included observations on the magnitude of the distresses and levels of destruction---changes, produced by the intense weather and upset climate from the storm. The data gathered were recorded following a categorization of impacts. It also included a description of the different coastal communities after being impacted and affected by the storm.

Biodiversity in the Republic of Macedonia

Status and trends of biodiversity components in Republic of Macedonia are presented in this article. The monitoring of biodiversity components is conducted according to the criteria of SEBI 2010 （Streamlining European 2010 Biodiversity Indicators） for establishment of consistency at global, regional, EU and national indicator level. Two core segments of the Biodiversity Strategy and Action Plan of Republic of Macedonia are presented as well as the draft list of biodiversity indicators. Ecosystems and biotopes （presented with plant communities） are explained from which 30 Corine habitat classes are identified for the Republic of Macedonia. The number of endemic and endangered species from different taxonomic groups of vascular plants, fungi, fauna, and Emerald species with European importance are presented. Agro-biodiversity, structure of agriculture land, autochthonic breeds of domestic animals as well as the network of protected areas in Republic of Macedonia are presented. At the end conclusion remarks are given for future necessary activities at national and international level regarding monitoring and conservation of the biodiversity.

Pollination interactions reveal direct costs and indirect benefits of plant-plant facilitation for ecosystem engineers

Aims Ecosystem engineers substantially modify the environment via their impact on abiotic conditions and the biota,resulting in facilitation of associated species that would not otherwise grow.Yet,reciprocal effects are poorly understood as studies of plant–plant interactions usually estimate only benefits for associated species,while how another trophic level may mediate direct and indirect feedback effects for ecosystem engineers is hardly considered.Methods We ran a field experiment with two ecosystem engineers(Arenaria tetraquetra and Hormathophylla spinosa)blooming either alone or with associated plants to decompose net effects and to test the hypothesis that pollinator-mediated interactions provide benefits that balance costs of facilitation by ecosystem engineers.Important Findings We found that net costs of facilitation are accompanied by pollinator-mediated benefits.Despite ecosystem engineers producing fewer flowers per plant,they were visited by more and more diverse pollinators per flower when blooming with associated plants than when blooming alone.Although seed production per plant was higher when ecosystem engineers bloomed alone,fruit set and seed set varied between species.In one case(A.tetraquetra),fruit and seed sets were negatively affected by the presence of associated plants,whereas,in another case(H.spinosa),fruit set and seed set were higher and unaffected when ecosystem engineers bloomed with associated plants,respectively.Our findings suggest that besides experiencing direct costs,ecosystem engineers can also benefit from facilitating other species via increasing their own visibility to pollinators.Thus,we highlight that pollination interactions can compensate for costs of facilitation depending on ecosystem engineer species.This study illuminates how the outcome of direct plant–plant interactions might be mediated by indirect interactions including third players.

Hydrogen-bonding directed cocrystallization of flexible piperazine with hydroxybenzoic acid derivatives:Structural diversity and synthon prediction

Four hydroxybenzoic acid building blocks, m-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxyterephthalic acid, and 5-hydroxyisophthalic acid, have been synthesized as robust cocrystallizing agents and employed in reactions with piperazine, including [（C4H12N2 2＋）.（C7H5O3-）2] （l）, [（CaH12N2 2＋）.（C7H5O4-）2] （2）, [（C4H12N2 2＋）.（C8H5O6 2- ）] （3）, and [（C4H12N2 2＋）1/2. （C8H5O5）] . 2H2O （4）. Hydrogen-bonded directed assemblies of four salts were validated by single-crystal X-ray diffraction analysis. In compounds 1-4, hydroxybenzoic acids are all deprotonated and piperazine molecules are all protonated to form piperazine dications and keep the chair conformation. Thermal stability of these compounds has been investigated.