水稻SSR标记的遗传多样性研究进展

本文从SSR标记优点和适用于研究水稻遗传多样性入手,综述了SSR标记在水稻核心种质构建与评价、遗传结构、稻种起源演化等方面的研究进展。总结了水稻遗传多样性的地带性特征（云南是中国稻种资源的最大遗传多样性中心和优异种质的富集地;西南稻区粳稻品种遗传多样性最丰富;南方稻区粳稻品种的遗传多样性高于北方粳稻遗传多样性）、遗传多样性与生态地理位置密切相关、目前水稻品种遗传基础狭窄、多样性降低等特征,分析了遗传多样性成因及影响因素,特别指出了育种行为对遗传多样性的影响,并针对当前水稻品种遗传多样性较低的问题提出了对策。     

遗传资源数字序列信息在生物多样性保护中的应用及对惠益分享制度的影响

遗传资源数字序列信息是近年来DNA测序技术的产物, 目前已经渗透到生命科学和环境科学等领域。遗传资源数字序列信息的应用有助于解释生命的分子基础和进化理论, 为生物多样性的保护和可持续利用提供新的技术手段。随着《名古屋议定书》的生效和履行, 各缔约方对遗传资源惠益分享的认识逐步提高, 并采取有效的立法、行政等措施对本国的生物遗传资源进行管制。遗传数字序列信息作为一种特殊的非实物性质的信息资源, 将会给获取与惠益分享制度带来挑战。近几年, 遗传资源数字序列信息已成为《生物多样性公约》缔约方大会谈判的焦点议题。中国是生物多样性大国, 也是近年来生物技术发展较快的国家之一。中国作为《名古屋议定书》的缔约方, 应积极参与遗传资源数字序列信息相关的研究, 并应对由此带来的各种挑战。     

中国履行《生物多样性公约》二十年: 行动、进展与展望

1992年6月联合国环境与发展大会(UNCED)通过了具有里程碑意义的《生物多样性公约》, 至今已经20年。在此期间, 中国1993年建立了履行《公约》的国家协调机制, 1995-1997年实施了“中国生物多样性国情研究”, 2007-2010年编制了《中国生物多样性保护国家战略与行动计划》, 2011年建立了“中国生物多样性保护国家委员会”, 并针对《生物多样性公约》的目标, 实施了多项生物多样性研究和保护行动, 包括森林、草原、荒漠、湿地、海洋等自然生态系统保护; 物种资源调查、编目、数据库建设以及珍稀濒危物种保护; 外来入侵种防治与转基因生物生态风险评估等。同时, 在生物多样性本底查明、监测体系建立、就地保护、遗传资源获取与惠益分享、传统知识的保护与应用等方面还存在很多挑战, 为此, 本文有针对性地提出了区域生物多样性本底查明、就地保护和遗传资源及相关传统知识获取与惠益分享等未来重点研究方向。     

印度生物遗传资源和相关传统知识获取制度发展动态研究

印度是世界上生物多样性最丰富的国家之一,主张遗传资源主权归国家所有并实现遗传资源惠益公平分享。印度政府于2003年颁布了《生物多样性法》,2004年又补充颁布了《生物多样性条例》,明确规定国家对其生物资源及相关传统知识的主权、保护原则、主管部门和管理体系、获取和惠益分享等问题。2014年又制订发布了《生物资源及相关传统知识获取规则指南》,对生物考察和利用、商业开发的惠益形式与比例、成果转化程序与惠益分享方式、知识产权获取程序与惠益分享形式、第三方转让为研究或商业利用、豁免审批情况等都作出了详细明确的规定。从印度遗传资源获取与惠益分享制度体系发展动态来看,印度的制度构建过程是循序渐进,不断更新,逐步趋于完善、细化。印度的遗传资源制度体系建设紧跟国际发展形势,从原则性的规定发展到具体措施。印度与中国生物遗传资源及相关传统知识国情相似,国际谈判立场一致,印度的遗传资源获取与惠益分享管理制度体系构建思路值得中国在国内遗传资源获取与惠益分享国家制度体系构建借鉴。     

豫西山区日本落叶松林下植物物种多样性的研究

生物多样性是指各种生命形式的资源,它包括地球上所有植物、动物、微生物物种及它们所有基因,以及生物与其环境相互作用形式的生态系统与生物过程,它包括三个层次,即遗传多样性、物种多样性与生态系统多样性［１］。生物多样性对人类生存与发展,以及对维持整个地球的...     

巴西生物遗传资源获取与惠益分享管理制度研究

巴西是世界上生物多样性最丰富的国家之一,同时也曾一度是世界遗传资源的主要提供者。巴西很早就意识到保护本国生物遗传资源的重要性,巴西政府于2001年发布了《巴西保护生物多样性和遗传资源暂行条例》。随后又对《暂行条例》进行了数十次修订,直到2015年由总统签署以宪法修正案的形式通过了《生物多样性保护法》(第13.123号法律)。巴西立法对有关概念和术语做了比《名古屋议定书》更为详细的区分和解释,并分别对生物遗传资源与传统知识的获取、审批、转让、惠益分享、行政处罚等内容做出了规定。为了更好地管理生物遗传资源,巴西还成立了"遗传资源委员会(CGEN)",并建立了"国家惠益分享基金(FNRB)"。中国与巴西同属生物多样性大国,且国情相似,本文对巴西遗传资源立法过程及其在遗传资源获取程序、管理机构、惠益分享等方面的相关规定进行了系统整理分析,为国内立法提供参考依据。     

《生物多样性公约》对遗传资源国际交流政策的影响

《生物多样性公约》于1992年在巴西里约热内卢签订,1993年生效。该公约提出了“国家对生物遗传资源拥有主权、获取生物遗传资源须事先得到资源所有者的知情同意、利用生物遗传资源所产生的利益应由资源所有者和开发者公平分享”三项基本原则,其生效与实施促进了各国生物多样性保护的立法行动,在维护资源原产国利益方面发挥了积极的作用,同时也给遗传资源的国际交流增添了一些障碍。本文介绍了《生物多样性公约》中有关生物遗传资源获取和利益分享的条款及其对国际交流政策的影响,并提出了加强遗传资源国际交换的对策和建议。     

普遍野生稻和亚洲栽培稻遗传多样性的研究

用 ４４个 ＲＦＬＰ标记对来自中国、印度、泰国等亚洲 １０个国家的普通野生稻（简称普野,下同）和来自多个国家的７５个栽培稻品种,从多态位点的比率、等位基因数、基因型数、平均杂合度及平均基因多样性等多个方面,比较了不同国家和不同地区的普通野生稻、栽培稻籼粳亚种及栽培稻与普野之间遗传多样性的差异。结果表明：中国普野的遗传多样性最大;其次是印度普野;南亚普野的平均基因多样性大于东南亚普野,而多态位点的比率、等位基因数及基因型数等却低于东南亚普野;栽培稻的遗传多样性明显小于普通野生稻。在所检测的４４个位点中,栽培稻的多态位点数仅为野生稻的３／４,等位基因数约为野生稻的６０％,基因型种类约为野生稻的１／２。栽培稻中籼稻的遗传多样性高于粳稻。在平均每个位点的实际杂合度上,以中国普野杂合度最高,普通野生稻是栽培稻的２倍。说明从野生稻演化成栽培稻的过程中,经过自然选择和人工选择,杂合度降低,等位基因减少,基因多样性下降。     

中国野生大豆遗传资源搜集基本策略与方法

遗传资源搜集原则是通过种子采集追求样本具有最高程度的遗传多样性。为了合理而有效地搜集野生大豆资源,近年来通过野生大豆居群考察和遗传多样性分析,初步明确了野生大豆资源居群的遗传多样性分布动态:遗传多样性地理的和生态的区域性、生态系统内居群的遗传相关性及各种生境下居群遗传多样性差异,从理论上奠定了野生大豆资源合理有效搜集的依据。根据居群遗传多样性的分布规律,初步建立了居群野生大豆资源的搜集策略和方法。     

广西地方稻种资源核心种质构建和遗传多样性分析

以丁颖分类体系分组原则与组内逐层聚类取样方法,对8609份广西地方栽培稻资源表型数据信息进行分析,通过对表型保留比例等评价指标的多重比较确定核心种质总体取样比例,构建出占总体样本5%(414份)的广西地方栽培稻资源初级核心种质。初级核心种质能代表总体遗传变异的89%。用34对SSR分子标记对初级核心种质进行遗传多样性分析,结果表明:广西地方栽培稻资源有较高的遗传多样性(等位基因数A为4.91,Nei’s多样性指数为0.574)。就Nei’s遗传多样性指数而言,粳稻高于籼稻,晚稻高于早稻,水稻高于陆稻,糯稻高于粘稻;来自桂中的稻种资源具有最高的遗传多样性。研究最终利用SSR数据,把414份初级核心种质压缩50%后形成209份核心种质,核心种质基因保留比例达到98%以上,有效代表了广西地方栽培稻资源多样性水平。     

Response diversity determines the resilience of ecosystems to environmental change

A growing body of evidence highlights the importance of biodiversity for ecosystem stability and the maintenance of optimal ecosystem functionality. Conservation measures are thus essential to safeguard the ecosystem services that biodiversity provides and human society needs. Current anthropogenic threats may lead to detrimental (and perhaps irreversible) ecosystem degradation, providing strong motivation to evaluate the response of ecological communities to various anthropogenic pressures. In particular, ecosystem functions that sustain key ecosystem services should be identified and prioritized for conservation action. Traditional diversity measures (e.g. ‘species richness’) may not adequately capture the aspects of biodiversity most relevant to ecosystem stability and functionality, but several new concepts may be more appropriate. These include ‘response diversity’, describing the variation of responses to environmental change among species of a particular community. Response diversity may also be a key determinant of ecosystem resilience in the face of anthropogenic pressures and environmental uncertainty. However, current understanding of response diversity is poor, and we see an urgent need to disentangle the conceptual strands that pervade studies of the relationship between biodiversity and ecosystem functioning. Our review clarifies the links between response diversity and the maintenance of ecosystem functionality by focusing on the insurance hypothesis of biodiversity and the concept of functional redundancy. We provide a conceptual model to describe how loss of response diversity may cause ecosystem degradation through decreased ecosystem resilience. We explicitly explain how response diversity contributes to functional compensation and to spatio‐temporal complementarity among species, leading to long‐term maintenance of ecosystem multifunctionality. Recent quantitative studies suggest that traditional diversity measures may often be uncoupled from measures (such as response diversity) that may be more effective proxies for ecosystem stability and resilience. Certain conclusions and recommendations of earlier studies using these traditional measures as indicators of ecosystem resilience thus may be suspect. We believe that functional ecology perspectives incorporating the effects and responses of diversity are essential for development of management strategies to safeguard (and restore) optimal ecosystem functionality (especially multifunctionality). Our review highlights these issues and we envision our work generating debate around the relationship between biodiversity and ecosystem functionality, and leading to improved conservation priorities and biodiversity management practices that maximize ecosystem resilience in the face of uncertain environmental change.     

高寒草甸群落植物多样性和初级生产力沿海拔梯度变化的研究

 对不同海拔梯度高寒草甸群落植物多样性和初级生产力关系的研究结果表明：1）不同海拔梯度上,中间海拔梯度群落植物多样性最高,即物种丰富度、均匀度和多样性最大;2）不同海拔梯度上,群落生产力水平和物种丰富度中等时,物种多样性最高;3）随着海拔的逐渐升高,地上生物量逐渐减少;4）地下生物量具有“V”字形季节变化规律,在牧草返青期和枯黄期地下生物量最大,7月最小,且地下生物量主要分布在0～10 cm的土层中。地下生物量垂直分布呈明显的倒金字塔特征。     

Genetic variation in a tropical tree species influences the associated epiphytic plant and invertebrate communities in a complex forest ecosystem

Genetic differences among tree species, their hybrids and within tree species are known to influence associated ecological communities and ecosystem processes in areas of limited species diversity. The extent to which this same phenomenon occurs based on genetic variation within a single tree species, in a diverse complex ecosystem such as a tropical forest, is unknown. The level of biodiversity and complexity of the ecosystem may reduce the impact of a single tree species on associated communities. We assessed the influence of within-species genetic variation in the tree Brosimum alicastrum (Moraceae) on associated epiphytic and invertebrate communities in a neotropical rainforest. We found a significant positive association between genetic distance of trees and community difference of the epiphytic plants growing on the tree, the invertebrates living among the leaf litter around the base of the tree, and the invertebrates found on the tree trunk. This means that the more genetically similar trees are host to more similar epiphyte and invertebrate communities. Our work has implications for whole ecosystem conservation management, since maintaining sufficient genetic diversity at the primary producer level will enhance species diversity of other plants and animals.     

Nontrophic interactions, biodiversity, and ecosystem functioning: an interaction web model

Research into the relationship between biodiversity and ecosystem functioning has mainly focused on the effects of species diversity on ecosystem properties in plant communities and, more recently, in food webs. Although there is growing recognition of the significance of nontrophic interactions in ecology, these interactions are still poorly studied theoretically, and their impact on biodiversity and ecosystem functioning is largely unknown. Existing models of mutualism usually consider only one type of species interaction and do not satisfy mass balance constraints. Here, we present a model of an interaction web that includes both trophic and nontrophic interactions and that respects the principle of mass conservation. Nontrophic interactions are represented in the form of interaction modifications. We use this model to study the relationship between biodiversity and ecosystem properties that emerges from the assembly of entire interaction webs. We show that ecosystem properties such as biomass and production depend not only on species diversity but also on species interactions, in particular on the connectance and magnitude of nontrophic interactions, and that the nature, prevalence, and strength of species interactions in turn depend on species diversity. Nontrophic interactions alter the shape of the relationship between biodiversity and biomass and can profoundly influence ecosystem processes.     

Natural enemy diversity and pest control: patterns of pest emergence with agricultural intensification

Concern over declining biodiversity and the implications for continued provision of ecosystem services has led, recently, to intense research effort to describe relationships between biodiversity and ecosystem functioning. Here we extend this effort to the relationship between natural enemy species diversity and natural pest control. From simple modelled food‐webs and simulations of natural enemy species loss we derive specific predictions concerning the effect of herbivore life‐history traits, such as life‐cycle type and concealment, on the shape (reflecting diversity effects) and variance (reflecting species composition effects) of the relationship between natural enemy diversity and pest‐control. We show that these predictions are consistent with the emergence of different pest types following intensification of rice production in Asia. We suggest that basic biological insights can help define the structure of ecological processes and allow more accurate predictions of the effect of species loss on the delivery of ecosystem services.     

Biodiversity mitigates trade-offs among species functional traits underpinning multiple ecosystem services

Biodiversity loss and its effects on humanity is of major global concern. While a growing body of literature confirms positive relationships between biodiversity and multiple ecological functions, the links between biodiversity, ecological functions and multiple ecosystem services is yet unclear. Studies of biodiversity–functionality relationships are mainly based on computer simulations or controlled field experiments using only few species. Here, we use a trait-based approach to integrate plant functions into an ecosystem service assessment to address impacts of restoration on species-rich grasslands over time. We found trade-offs among functions and services when analysing contributions from individual species. At the community level, these trade-offs disappeared for almost all services with time since restoration as an effect of increased species diversity and more evenly distributed species. Restoration to enhance biodiversity also in species-rich communities is therefore essential to secure higher functional redundancy towards disturbances and sustainable provision of multiple ecosystem services over time.     

Interactive prey and predator diversity effects drive consumption rates

The positive relationship between biodiversity and ecosystem functioning is mainly derived from studies concerning primary producers, whereas a generalization of this relationship for higher trophic levels is more difficult. Furthermore, most evidence of the biodiversity–ecosystem functioning relationship is derived from experiments manipulating only one trophic level and, as a consequence, interactive diversity effects at multiple trophic levels have mostly been ignored. Here, we performed a mesocosm experiment in which we manipulated functional group diversity at two trophic levels (primary and secondary consumers) applying a full‐factorial design. More specifically, we asked whether 1) predator functional diversity affects prey mortality rates, 2) prey functional diversity affects prey mortality rates, 3) whether there are interactive effects of simultaneous diversity changes at both trophic levels. For each trophic level we used two functional groups, i.e. organisms belonging to two different habitat domains: at the higher trophic position 1) a ground foraging spider species and 2) a spider species foraging in the vegetation canopy and at the lower trophic position 3) a ground living cricket species and 4) leafhoppers living in the vegetation canopy. Increasing predator functional group diversity increased prey mortality by 53%, and increasing prey functional group diversity increased prey mortality by 24%. Further, prey mortality was highest at the uppermost level of functional group diversity (142% increase in prey mortality compared to single prey and predator functional diversity), most likely due to resource partitioning between the predators. This finding demonstrates that a multi‐trophic perspective is necessary, and that previous studies focusing on only one trophic level have most likely underestimated the strength of the relationship between biodiversity and ecosystem functioning.     

Ecosystem engineering and biodiversity in coastal sediments: posing hypotheses

Coastal sediments in sheltered temperate locations are strongly modified by ecosystem engineering species such as marsh plants, seagrass, and algae as well as by epibenthic and endobenthic invertebrates. These ecosystem engineers are shaping the coastal sea and landscape, control particulate and dissolved material fluxes between the land and sea, and between the benthos and the passing water or air. Above all, habitat engineering exerts facilitating and inhibiting effects on biodiversity. Despite a strongly growing interest in the functional role of ecosystem engineering over the recent years, compared to food web analyses, the conceptual understanding of engineering-mediated species interactions is still in its infancy. In the present paper, we provide a concise overview on current insights and propose two hypotheses on the general mechanisms by which ecosystem engineering may affect biodiversity in coastal sediments. We hypothesise that autogenic and allogenic ecosystem engineers have inverse effects on epibenthic and endobenthic biodiversity in coastal sediments. The primarily autogenic structures of the epibenthos achieve high diversity at the expense of endobenthos, whilst allogenic sediment reworking by infauna may facilitate other infauna and inhibits epibenthos. On a larger scale, these antagonistic processes generate patchiness and habitat diversity. Due to such interaction, anthropogenic influences can strongly modify the engineering community by removing autogenic ecosystem engineers through coastal engineering or bottom trawling. Another source of anthropogenic influences comes from introducing invasive engineers, from which the impact is often hard to predict. We hypothesise that the local biodiversity effects of invasive ecosystem engineers will depend on the engineering strength of the invasive species, with engineering strength defined as the number of habitats it can invade and the extent of modification. At a larger scale of an entire shore, biodiversity need not be decreased by invasive engineers and may even increase. On a global scale, invasive engineers may cause shore biota to converge, especially visually due to the presence of epibenthic structures.     

Biodiversity and ecosystem functioning: recent theoretical advances

The relationship between biodiversity and ecosystem functioning has emerged as a major scientific issue today. As experiments progress, there is a growing need for adequate theories and models to provide robust interpretations and generalisations of experimental results, and to formulate new hypotheses. This paper provides an overview of recent theoretical advances that have been made on the two major questions in this area: (1) How does biodiversity affect the magnitude of ecosystem processes (short‐term effects of biodiversity)? (2) How does biodiversity contribute to the stability and maintenance of ecosystem processes in the face of perturbations (long‐term effects of biodiversity)?
Positive short‐term effects of species diversity on ecosystem processes, such as primary productivity and nutrient retention, have been explained by two major types of mechanisms: (1) functional niche complementarity (the complementarity effect), and (2) selection of extreme trait values (the selection effect). In both cases, biodiversity provides a range of phenotypic trait variation. In the complementarity effect, trait variation then forms the basis for a permanent association of species that enhances collective performance. In the selection effect, trait variation comes into play only as an initial condition, and a selective process then promotes dominance by species with extreme trait values. Major differences between within‐site effects of biodiversity and across‐site productivity–diversity patterns have also been clarified. The local effects of diversity on ecosystem processes are expected to be masked by the effects of varying environmental parameters in across‐site comparisons.
A major reappraisal of the paradigm that has dominated during the last decades seems necessary if we are to account for long‐term effects of biodiversity on ecosystem functioning. The classical deterministic, equilibrium approaches to stability do not explain the reduced temporal variability of aggregate ecosystem properties that has been observed in more diverse systems. On the other hand, stochastic, nonequilibrium approaches do show two types of biodiversity effects on ecosystem productivity in a fluctuating environment: (1) a buffering effect, i.e., a reduction in the temporal variance; and (2) a performance‐enhancing effect, i.e., an increase in the temporal mean. The basic mechanisms involved in these long‐term insurance effects are very similar to those that operate in short‐term biodiversity effects: temporal niche complementarity, and selection of extreme trait values. The ability of species diversity to provide an insurance against environmental fluctuations and a reservoir of variation allowing adaptation to changing conditions may be critical in a long‐term perspective.
These recent theoretical developments in the area of biodiversity and ecosystem functioning suggest that linking community and ecosystem ecology is a fruitful avenue, which paves the way for a new ecological synthesis.