植物保护遗传学研究进展

保护遗传学是过用遗传学的原理和研究手段,以生物多样性尤其是遗传多样性的研究和保护为核心的一门新兴学科,近几十年来,遗传学研究在生物多样性保护的理论和实践中发挥着越来越重要的作用。本文简要回顾了保护遗传学的发展历史,研究方向和涉及的概念,着重介绍了植物保护遗传学研究所取得的一些进展,包括植物系统发育重建和保护单元的确定,遗传多样性与物种和群体适应性之间的关系,群体遗传结构与保护策略的制定以及植物遗传资源的鉴定和利用等方面的内容,并强调保护遗传学研究是未来生物多样性和保护生物学研究中一个亟待加强的研究领域。     

系统发育多样性测度及其在生物多样性保护中的应用

生物多样性保护面临两个基本问题：如何确定生物多样性测度以及如何保护生物多样性。传统的生物多样性测度是以物种概念为基础的,用生态学和地理学方法确定各种生物多样性指数。其测度依赖于样方面积的大小,并且所有的物种在分类上同等对待。系统发育多样性测度基于系统发育和遗传学的理论和方法,能确定某一物种对类群多样性的贡献大小。该方法比较复杂,只有在类群的系统发育或遗传资料比较齐全时方能应用。本文认为,物种生存力途径和系统发育多样性测度相结合有助于确定物种和生态系统保护的优先秩序。     

系统发育多样性测定及其在生物多样性保护中的应用

生物多样性保护面临两个基本问题：如何确定生物多样性测度以及如何保护生物多样性。传统的生物多样性测度是以物种概念为基础的,用生态学和地理学方法确定各种生物多样性指数。其测度依赖于样方面积的大小,并且所有的物种在分类上同等对待。系统发育多样性测度基于系统发育和遗传学的理论和方法,能确定某一物种对类群多样性的贡献大小。该方法比较复杂,只有在类群的系统发育或遗传资料比较齐全时方能应用。本文认为,物种生存力     

不仅仅是遗传多样性:植物保护遗传学进展

保护遗传学研究的是影响物种灭绝的遗传因素以及濒危物种的遗传管理, 以降低物种的灭绝风险。本文从遗传多样性本身及其对生态系统的影响两个方面介绍了植物保护遗传学的最新进展。根据遗传标记的功能, 保护遗传学研究可分为选择中性遗传变异研究和适应性遗传变异两个方面。对于目前主要采用的选择中性遗传标记研究, 本文着重介绍了以下方面的最新进展: (1)利用遗传标记进行个体、物种或遗传单元的鉴定, 从而有效地设计保护策略, 避免在迁地保护中混淆物种, 提高保护效率; (2)应重视由于物种自身生殖、扩散等原因造成的隐性瓶颈效应。由于选择中性遗传标记并不能准确反映物种的适应性遗传基础, 从适应性遗传变异角度研究濒危物种的进化潜力已成为保护遗传学的研究前沿。大部分相关研究还集中在利用基因组扫描检测受选择的位点, 而对功能基因的适应性研究还比较少。景观遗传学旨在解释景观和生境影响下的种群间基因流和遗传多样性格局, 这方面研究将会促进我们更多了解种群基因流的地理限制因子和不同景观基质下的种群遗传差异。遗传多样性作为物种的一种属性亦可在一定程度上反馈, 并影响生态系统。这提示我们不仅仅是濒危物种, 常见物种的遗传多样性及其保护亦很重要。最后, 我们从4个方面对保护遗传学研究进行了展望, 包括应加强将生态系统各环节联系起来研究遗传多样性, 在技术手段上利用多态性更丰富的分子标记, 同时强调了对常见物种保护遗传学研究的重要性, 并初步分析了我国保护遗传学研究与国际水平的差距, 建议加强种群遗传学和进化生物学基础理论的学习。     

遗传多样性与濒危植物保护生物学研究进展

尽管对于濒危物种的遗传学人们已经进行了大量研究,但是种群遗传学在植物保护中的实际地位尚存在很大争议。濒危物种的遗传多样性可能会由于遗传漂变、近交的作用而丧失;但这种丧失更可能是濒危的结果而不是濒危的起因。遗传多样性水平与物种生存力之间没有任何必然的联系。但植物种群遗传结构如果由于自交不亲和等位基因的丧失和与亲缘种杂交造成的遗传同化而发生改变,那么它对物种生存力会产生明显负作用。     

景观遗传学：概念与方法

全球变化下的物种栖息地丧失和破碎化给生物多样性保护带来了新的问题和挑战,生物多样性保护必须由单纯的物种保护上升到栖息地景观的保护。景观遗传学是定量确定栖息地景观特征对种群遗传结构影响的一门交叉学科,在生物保护及自然保护区管理方面有巨大的潜力。从生物多样性保护的角度评述了景观结构与遗传多样性的关系,介绍了景观遗传学的基本概念,研究尺度和方法,并对景观遗传学当前的研究焦点及面临的挑战做了总结。     

中国兽类遗传与进化研究进展与展望

中国兽类物种丰富,且具有150个特有种。本文综述了60年来中国兽类遗传与进化的研究进展,内容涵盖系统发育关系重建、遗传多样性评估、种群遗传结构、适应性进化以及趋同进化的分子机制。本文重点概述了食肉目（大、小熊猫）、有蹄类、翼手目、灵长目、小型兽类以及海兽类等重要类群的研究进展,为中国兽类的物种保护提供了重要资料。另外,本文还对中国兽类遗传与进化研究未来的研究方向提出几点建议,包括运用各种组学技术、筛选新型遗传标记和候选基因（调控序列）、结合表观遗传学并借助进化发育生物学研究方法,以期全面深入地理解中国兽类分类地位、起源以及特异表型产生和独特适应的发育遗传学机制等,进而实现“天人合一”保护生物学的新理念和新愿景。     

中国濒危兽类保护遗传学研究进展与展望

我国是全球生物多样性大国,拥有包括大熊猫、金丝猴、华南虎、麋鹿、白鱀豚等特有物种和旗舰物种在内的丰富兽类资源。近几十年来,土地利用模式转变、盗猎、环境污染、气候变化等因素使许多兽类物种面临生存威胁,导致物种遗传多样性丧失。而遗传多样性是生物多样性的基本组成部分,决定了物种和种群能否长期生存。保护遗传学作为保护生物学的一大分支学科,旨在通过遗传学分析探明种群遗传变异和物种濒危的遗传学机制。近40年来,随着研究手段和技术的不断发展,我国兽类保护遗传学在遗传多样性和近交水平评估、景观遗传学、生态遗传学和圈养种群遗传管理等方面都取得了重要成果。然而,未来人类社会发展可能为濒危兽类带来的威胁依然存在,高通量测序等新技术的进一步发展则能够帮助我们更加深入地了解濒危物种和种群遗传适应与濒危机制,从而实现对濒危兽类的有效管理与保护。     

保护生物学一新分支学科——保护遗传学

研究人类对生物多样性的影响以及防止物种灭绝是保护生物学的两个主要目的。随着环境日益恶化、分子遗传学的迅速发展以及保护生物学和分子遗传学的不为民相互渗透,和产生了一全新的分支学科－－保护遗传学。保护遗传学是保护生物学研究中的一个核心部分,主要研究濒危物种的遗传多样性和保护物种的进化潜力。目前保护遗传学已成为国际上的一个研究热点,但在我国才刚刚起步,为此,本文就保护,遗传学的产生和发展及其研究内容和意义作一简要介绍,以推动我国在该方面的研究。     

系统发育多样性在植物区系研究与生物多样性保护中的应用

利用系统发育关系从进化角度理解物种的组成、分布格局对可为有效保护和合理利用生物多样性提供科学依据。以支长为基础的系统发育多样性是最基本的测度指数,由此衍生出的几十个参数加大了选择难度。根据具体研究的问题选择合适的指标,是目前最为可行的方案,已经在植物系统发育区系研究和生物多样性保护中取得了一系列研究成果。DNA序列迅速积累特别是DNA条形码项目在全球的大力发展,提供了海量的标准化数据,为构建解决能力较好的宏系统发育树提供了可能。但是围绕系统发育多样性开展的相关研究还需要更多的物种分布、环境因子、气候等基础数据,同时对其在生态系统功能上的表征作用需要进一步验证。     

雪豹保护遗传学和基因组学研究进展

雪豹 (Panthera uncia) 隶属于食肉目猫科豹属,是生活在青藏高原及其周边地区的旗舰物种。随着分子生物学和高通量测序技术的发展,雪豹保护遗传学和保护基因组学研究得到快速的发展,其中非损伤性遗传取样法显著推动了雪豹保护遗传学研究。本文综述了非损伤性遗传取样法在雪豹物种鉴定、个体识别和性别鉴定等研究中的应用,雪豹的系统发生地位、系统地理格局和种群遗传结构及其亚种争议、演化历史、适应性演化和基因组特征等保护遗传学和基因组学方面的研究现状和进展,并对雪豹保护遗传学和基因组学未来发展趋势进行了展望,以期促进雪豹保护生物学研究和保护对策的科学制定。     

Conservation genetics and genomics of threatened vertebrates in China

Conservation genetics and genomics are two independent disciplines that focus on using new techniques in genetics and genomics to solve problems in conservation biology. During the past two decades, conservation genetics and genomics have experienced rapid progress. Here, we summarize the research advances in the conservation genetics and genomics of threatened vertebrates (e.g., carnivorans, primates, ungulates, cetaceans, avians, amphibians and reptiles) in China. First, we introduce the concepts of conservation genetics and genomics and their development. Second, we review the recent advances in conservation genetics research, including noninvasive genetics and landscape genetics. Third, we summarize the progress in conservation genomics research, which mainly focuses on resolving genetic problems relevant to conservation such as genetic diversity, genetic structure, demographic history, and genomic evolution and adaptation. Finally, we discuss the future directions of conservation genetics and genomics.     

Understanding Quantitative Genetics in the Systems Biology Era

Biology is now entering the new era of systems biology and exerting a growing influence on the future development of various disciplines within life sciences. In early classical and molecular periods of Biology, the theoretical frames of classical and molecular quantitative genetics have been systematically established, respectively. With the new advent of systems biology, there is occurring a paradigm shift in the field of quantitative genetics. Where and how the quantitative genetics would develop after having undergone its classical and molecular periods? This is a difficult question to answer exactly. In this perspective article, the major effort was made to discuss the possible development of quantitative genetics in the systems biology era, and for which there is a high potentiality to develop towards "systems quantitative genetics". In our opinion, the systems quantitative genetics can be defined as a new discipline to address the generalized genetic laws of bioalleles controlling the heritable phenotypes of complex traits following a new dynamic network model. Other issues from quantitative genetic perspective relating to the genetical genomics, the updates of network model, and the future research prospects were also discussed.     

Conservation genetics in a globally changing environment: present problems,paradoxes and future challenges

Despite recent advances in conservation genetics and related disciplines and the growing impact that conservation genetics is having in conservation biology, our knowledge on several key issues in the field is still insufficient. Here we identify some of these issues together with addressing several paradoxes which have to be solved before conservation genetics can face new challenges that are appearing in the transitory phase from the population genetics into the population genomics era. Most of these issues, paradoxes and challenges, like the central dogma of conservation genetics, the computational, theoretical and laboratory experiment achievements and limitations in the conservation genetics field have been discussed. Further knowledge on the consequences of inbreeding and outbreeding depression in wild populations as well as the capacity of small populations to adapt to local environmental conditions is also urgently needed. The integration of experimental, theoretical and applied conservation genetics will contribute to improve our understanding of methodological and applied aspects of conservation genetics.     

Effects of chemical contaminants on genetic diversity in natural populations: implications for biomonitoring and ecotoxicology

The conservation of genetic diversity has emerged as one of the central issues in conservation biology. Although researchers in the areas of evolutionary biology, population management, and conservation biology routinely investigate genetic variability in natural populations, only a handful of studies have addressed the effects of chemical contamination on population genetics. Chemical contamination can cause population reduction by the effects of somatic and heritable mutations, as well as non-genetic modes of toxicity. Stochastic processes in small populations, increased mutation load, and the phenomenon of mutational meltdown are compounding factors that cause reduced fitness and accelerate the process of population extirpation. Although the original damage caused by chemical contaminants is at the molecular level, there are emergent effects at the level of populations, such as the loss of genetic diversity, that are not predictable based solely on knowledge of the mechanism of toxicity of the chemical contaminants. Therefore, the study of evolutionary toxicology, which encompasses the population-genetic effects of environmental contaminants, should be an important focus of ecotoxicology. This paper reviews the issues surrounding the genetic effects of pollution, summarizes the technical approaches that can be used to address these issues, and provides examples of studies that have addressed some of them.     

Applications of landscape genetics in conservation biology: concepts and challenges

Landscape genetics plays an increasingly important role in the management and conservation of species. Here, we highlight some of the opportunities and challenges in using landscape genetic approaches in conservation biology. We first discuss challenges related to sampling design and introduce several recent methodological developments in landscape genetics (analyses based on pairwise relatedness, the application of Bayesian methods, inference from landscape resistance and a shift from population-based to individual-based analyses). We then show how simulations can foster the field of landscape genetics and, finally, elaborate on technical developments in sequencing techniques that will dramatically improve our ability to study genetic variation in wild species, opening up new and unprecedented avenues for genetic analysis in conservation biology.     

An essay on the necessity and feasibility of conservation genomics

The basic premise of conservation genetics is that small populations may be genetically threatened. The two steps leading to this premise are: (1) due to prominent influence of random genetic drift and inbreeding allelic and genotypic diversity in small populations is expected to be low, and (2) low allelic diversity and high homozygosity are expected to lead to immediate fitness decreases (inbreeding depression) and a compromised potential for evolutionary adaptation. Conservation genetic research has been strongly stimulated by the application of neutral molecular markers like microsatellites and AFLPs. In general these marker studies have provided evidence for step 1. It is less evident how these markers may provide evidence for step 2. In this essay we argue that, in order to get detailed insight in step 2, adopting a conservation genomic approach, in which conservation genetics will use approaches from ecological and evolutionary functional genomics (ecogenomics), is both necessary and feasible. Conservation genomics is necessary for studying functional genomic variation as function of drift and inbreeding, for studying the mechanisms that relate low genetic variation to low fitness, for integrating environmental and genetic approaches to conservation biology, and for developing modern, fast monitoring tools. The rapid technical and financial developments in genomics currently make conservation genomics feasible, and will improve feasibility in the very near future even further. We therefore argue that conservation genomics personifies part of the near future of conservation genetics.     

Black and white and read all over: the past,present and future of giant panda genetics

Few species attract much more attention from the public and scientists than the giant panda (Ailuropoda melanoleuca), a popular, enigmatic but highly endangered species. The application of molecular genetics to its biology and conservation has facilitated surprising insights into the biology of giant pandas as well as the effectiveness of conservation efforts during the past decades. Here, we review the history of genetic advances in this species, from phylogeny, demographical history, genetic variation, population structure, noninvasive population census and adaptive evolution to reveal to what extent the current status of the giant panda is a reflection of its evolutionary legacy, as opposed to the influence of anthropogenic factors that have negatively impacted this species. In addition, we summarize the conservation implications of these genetic findings applied for the management of this high‐profile species. Finally, on the basis of these advances and predictable future changes in genetic technology, we discuss future research directions that seem promising for giant panda biology and conservation.