Effect of biogeographic history on population vulnerability in European amphibians

The genetic diversity of populations, which contributes greatly to their adaptive potential, is negatively affected by anthropogenic habitat fragmentation and destruction. However, continental‐scale losses of genetic diversity also resulted from the population expansions that followed the end of the last glaciation, an element that is rarely considered in a conservation context. We addressed this issue in a meta‐analysis in which we compared the spatial patterns of vulnerability of 18 widespread European amphibians in light of phylogeographic histories (glacial refugia and postglacial routes) and anthropogenic disturbances. Conservation statuses significantly worsened with distances from refugia, particularly in the context of industrial agriculture; human population density also had a negative effect. These findings suggest that features associated with the loss of genetic diversity in post‐glacial amphibian populations (such as enhanced fixation load or depressed adaptive potential) may increase their susceptibility to current threats (e.g., habitat fragmentation and pesticide use). We propose that the phylogeographic status of populations (i.e., refugial vs. post‐glacial) should be considered in conservation assessments for regional and national red lists.     

Assessing the components of adaptive capacity to improve conservation and management efforts under global change

Natural‐resource managers and other conservation practitioners are under unprecedented pressure to categorize and quantify the vulnerability of natural systems based on assessment of the exposure, sensitivity, and adaptive capacity of species to climate change. Despite the urgent need for these assessments, neither the theoretical basis of adaptive capacity nor the practical issues underlying its quantification has been articulated in a manner that is directly applicable to natural‐resource management. Both are critical for researchers, managers, and other conservation practitioners to develop reliable strategies for assessing adaptive capacity. Drawing from principles of classical and contemporary research and examples from terrestrial, marine, plant, and animal systems, we examined broadly the theory behind the concept of adaptive capacity. We then considered how interdisciplinary, trait‐ and triage‐based approaches encompassing the oft‐overlooked interactions among components of adaptive capacity can be used to identify species and populations likely to have higher (or lower) adaptive capacity. We identified the challenges and value of such endeavors and argue for a concerted interdisciplinary research approach that combines ecology, ecological genetics, and eco‐physiology to reflect the interacting components of adaptive capacity. We aimed to provide a basis for constructive discussion between natural‐resource managers and researchers, discussions urgently needed to identify research directions that will deliver answers to real‐world questions facing resource managers, other conservation practitioners, and policy makers. Directing research to both seek general patterns and identify ways to facilitate adaptive capacity of key species and populations within species, will enable conservation ecologists and resource managers to maximize returns on research and management investment and arrive at novel and dynamic management and policy decisions.     

Implications of genetics and current protected areas for conservation of 5 endangered primates in China

Most of China's 24–28 primate species are threatened with extinction. Habitat reduction and fragmentation are perhaps the greatest threats. We used published data from a conservation genetics study of 5 endangered primates in China (Rhinopithecus roxellana, R. bieti, R. brelichi, Trachypithecus francoisi, and T. leucocephalus); distribution data on these species; and the distribution, area, and location of protected areas to inform conservation strategies for these primates. All 5 species were separated into subpopulations with unique genetic components. Gene flow appeared to be strongly impeded by agricultural land, meadows used for grazing, highways, and humans dwellings. Most species declined severely or diverged concurrently as human population and crop land cover increased. Nature reserves were not evenly distributed across subpopulations with unique genetic backgrounds. Certain small subpopulations were severely fragmented and had higher extinction risk than others. Primate mobility is limited and their genetic structure is strong and susceptible to substantial loss of diversity due to local extinction. Thus, to maximize preservation of genetic diversity in all these primate species, our results suggest protection is required for all sub‐populations. Key priorities for their conservation include maintaining R. roxellana in Shennongjia national reserve, subpopulations S4 and S5 of R. bieti and of R. brelichi in Fanjingshan national reserve, subpopulation CGX of T. francoisi in central Guangxi Province, and all 3 T. leucocephalus sub‐populations in central Guangxi Province.     

氟化物对植物生理生化的影响

综述了氟化物对植物的光合作用、时吸作用、膜生理和有机物的代谢等生理过程，及异常衰老和遗传变异的影响，并提出了今后的研究方向。     

大豆种质资源对斜纹夜蛾(PRODENIA LITURA)抗性的鉴定

在网室人工均匀接虫条件下 ,以叶面积损失百分率为指标 ,分别于 1997年和 1998年鉴定了从 6 72 4份大豆资源中筛选的 46份抗感材料及 5份江淮与南方大豆推广良种共 5 1份对斜纹夜蛾的抗性差异表现 .结果表明 ,品种间、观测日期间、年份间抗虫性有极显著差异 ;品种与观测日期间互作显著 ;品种与年份之间互作极显著 ;年份之间抗虫性表现极显著相关 .从供试资源中筛选出一批年份间表现相对一致的高抗种质 ,其抗性优于国际常用的抗源PI2 2 76 87、PI17145 1、PI2 2 935 8.表 3参 10     

三价钇对紫露草的遗传毒性研究

用紫露草四分体微核试验法和紫露草雄蕊毛细胞突变法研究了稀土元素三价钇的遗传毒性．结果表明：Y3＋能引起紫露草四分体微核率显著升高，提示Y3＋是诱变剂或纺锤丝毒剂；Y3＋能引起雄蕊毛细胞突变率显著升高，进一步明确Y3＋是诱变剂．     

实数编码遗传算法的评述

遗传算法是一种基于自然选择和遗传变异等生物进化机制的全局优化搜索算法．使用实数表示基因的实数编码遗传算法常用于求解连续函数优化等问题．本文阐述了实数编码遗传算法研究的有关工作进展，讨论了算法框架及特点，对实数编码遗传算法中常用的选择、交叉和变异算子进行了比较全面的形式化描述，并介绍了其未来研究方向．     

Reproductive Success of Captive-Bred Steelhead Trout in the Wild: Evaluation of Three Hatchery Programs in the Hood River

Abstract:  Population supplementation programs that release captive-bred offspring into the wild to boost the size of endangered populations are now in place for many species. The use of hatcheries for supplementing salmonid populations has become particularly popular. Nevertheless, whether such programs actually increase the size of wild populations remains unclear, and predictions that supplementation fish drag down the fitness of wild fish remain untested. To address these issues, we performed DNA-based parentage analyses on almost complete samples of anadromous steelhead ( Oncorhynchus mykiss ) in the Hood River in Oregon (U.S.A.). Steelhead from a supplementation hatchery (reared in a supplementation hatchery and then allowed to spawn naturally in the wild) had reproductive success indistinguishable from that of wild fish. In contrast, fish from a traditional hatchery (nonlocal origin, multiple generations in hatcheries) breeding in the same river showed significantly lower fitness than wild fish. In addition, crosses between wild fish and supplementation fish were as reproductively successful as those between wild parents. Thus, there was no sign that supplementation fish drag down the fitness of wild fish by breeding with them for a single generation. On the other hand, crosses between hatchery fish of either type (traditional or supplementation) were less fit than expected, suggesting a possible interaction effect. These are the first data to show that a supplementation program with native brood stock can provide a single-generation boost to the size of a natural steelhead population without obvious short-term fitness costs. The long-term effects of population supplementation remain untested.     

山西高原油松种群遗传多样性

用酸性聚丙烯酰胺凝胶电泳（A-PAGE）技术，分析了山西高原9个油松种群在醇溶蛋白水平上的遗传多样性。135份材料共分离出23条带，其中3条为共有带，多态性高达86．95％。全部材料共出现53种带型，9个不同油松种群的带型有差异，同一种群不同个体的带型也有所不同，说明山西高原的油松在遗传上已产生一定程度分化，在醇溶蛋白水平上呈现出遗传多态性。从供试材料的带型计算出油松遗传分化系数为0．1547。即在种群间的变异占总变异的15．47％，种群内变异为84．53％，大部分的遗传变异存在于种群内，但种群间的分化程度在松属树种中也属于较高水平。根据23个多态位点计算遗传相似系数和遗传距离，进行聚类分析，将山西高原9个油松种群聚为3个类群。