Genetic Variation in the Endangered Endemic Species Cycas fairylakea (Cycadaceae) in China and Implications for Conservation

Cycas fairylakea is an endangered endemic species in China. Genetic diversity within and among four natural populations of this species in China was investigated using amplified fragments length polymorphism (AFLP). A moderate to low level of intraspecific genetic diversity was detected in this species (at population level: P = 39.57 %, H₀ = 0.244; at species level: P = 60.22%, H₀ = 0.356). The among-population component accounted for, respectively, 25.7 and 31.5% of the genetic variation, according to AMOVA and Shannon’s index, indicating most of the genetic variation was found between individuals within populations. All four populations have opposite pyramid age structure, and few coning individuals, which is still decreasing. Possibly because of habitat degradation and environmental pollution, plant diseases and insect pests in the populations were extremely serious, suggesting that the main factors threatening the survival of C. fairylakea populations were not genetic variation, but human activities and the breeding system of this species.     

物种濒危的机制与保护对策

本文以生物多样性和保护生物学的若干基础理论为依据,分析了物种濒危的现状,论述了濒危物种的概念和特征、易于濒危和灭绝的类型,阐明了物种濒危的机制,并由此提出了濒危物种种质资源的保护对策。     

Endangered Medicinal Species of the Indian Ocean: Radical Need for Conservation

Life originated in the Oceans, which are also the most fertile source of chemically distinctive natural products that are mainly accumulated in living organisms. Several of these compounds show pharmacological activities, and are helpful for the invention and discovery of bioactive compounds, primarily for several fatal diseases. The Indian Ocean is home to several exotic species of flora and fauna. Several environmental and man‐made factors are responsible for deterioration of several precious biodiversity areas of the Ocean. The author, while highlighting the medicinal importance of these organisms, underlines the need for comprehensive conservatory measures on the part of the international community to be taken in order to maintain the rich Oceanic biodiversity.     

广西特有濒危植物狭叶坡垒群落特征研究

狭叶坡垒(Hopea chinensis)是国家二级重点保护植物,仅分布于广西十万大山。通过野外实地调查对狭叶坡垒群落特征的研究表明:在10个样点共3 200 m2的样方中,包含维管束植物82科168属265种,这些属可划分成11个分布区类型,其中热带分布的属占绝对优势,达83.7%,温带分布属占13.1%。群落生活型以高位芽植物为主,外貌主要由中小型为主的常绿高位芽植物所决定。狭叶坡垒群落结构复杂,可分为乔木层、灌木层和草本层3个层次,层间植物丰富。     

Conservation Genetics of Cicindela Deserticoloides, an Endangered Tiger Beetle Endemic to Southeastern Spain

Population surveys of the tiger beetle, Cicindela (Cephalota) deserticoloides, endemic to the few remaining salt steppes of southeastern Spain revealed only four extant colonies. DNA sequencing of some 1896 base pairs of mitochondrial DNA for one specimen each from three populations revealed only a single base pair change confined to a single of the three specimens, thus indicating an extremely low level of differentiation when compared to similar populations of Cicindela (s.l.) elsewhere. Divergence of C. deserticoloides from the closest relatives in the Iberian Peninsula was between 6.9 and 9.9%, attesting to the uniqueness of the species and its high conservation status. Habitat requirements appear to be phylogenetically conserved within Cephalota, but C. deserticoloides seems to be more narrowly confined to relatively drier conditions than its less endangered relatives. The geographic range of the relatives is wider and their local abundance higher, indicating that habitat specialization, low abundance and small geographic range in C. deserticoloides are correlated and in sum are responsible for its vulnerability to extinction.     

三峡库区消涨带特有濒危植物丰都车前Plantago fengdouensis的迁地保护

丰都车前(Plantago fengdouensis)为近年在三峡库区消涨带发现的一特有植物。通过多年的调查,发现该种仅分布于重庆市忠县、丰都县和巴南区等3个长江江心岛上,总共290株。随着三峡水库的逐步蓄水,丰都车前的自然分布区将于2006年全部水淹,使其成为因三峡工程建设而导致自然生境和野生居群全部毁灭的唯一的草本植物。为保护这一即将野外灭绝的稀有植物,在对其地理分布、生态学和群落学调查的基础上,对其形态特征、年生长周期和生殖值与同属植物车前(P.asiatica)和北美车前(P.virginica)进行了调查、试验和比较研究,表明丰都车前果期长、种子不适宜长距离传播和生殖值低以及长江水淹干扰是其狭域分布和数量稀少的主要原因。同时探讨了其迁地保护策略,并提出了下一步的研究和保护建议。     

三种兰科植物的保护遗传学研究初探

采用随机扩增多态 DNA(RAPD)分析研究了中国3种珍稀濒危兰科植物硬叶兜兰(Paphiopedilum micranthum Tang et Wang)、麻栗坡兜兰(P. malipoense S.C.Chen et Tsi)和独花兰(Changnienia amoena Chien)的遗传多样性与群体遗传结构.12个RAPD引物在2种兜兰中共扩增出131条带.对4个硬叶兜兰群体的检测表明其物种水平的多态条带百分率(PPB)为 71.6%,Nei 的基因多样度(h)为 0.217 1,Shannon多样性指数 (I) 为 0.330 1;4个群体的平均多样性水平为 PPB = 45.2%,h = 0.145 7,I = 0.220 4,低于远交兰花的平均水平.在总遗传变异中,群体间遗传变异占20.31%,略高于远交物种的平均水平.在物种水平上,麻栗坡兜兰的PPB为49.5%,h为0.117 4,I为0.176 4,均大大低于硬叶兜兰.对11个独花兰群体采用16个RAPD引物共扩增出119条带.物种水平PPB=76.5%,h=0.194 1,I=0.305 8;在群体水平上,上述3个指标的平均值则分别为37.2%、0.119 7和0.181 0,均低于远交兰花的平均水平.群体间的遗传变异占45.27%,遗传分化明显高于远交物种的平均水平.导致3个物种遗传多样性偏低而群体间遗传分化较高的主要原因在于人为的过度采挖和生境的片断化.研究结果为兰花保护策略和措施的制定提供了理论基础.     

中国特产2种濒危水韭雄性发育的比较研究

采用透射电镜和光镜比较观察了中华水韭和云贵水韭雄配子体及其精子的发育特征。结果显示:(1)2种水韭的雄配子体的寿命只有15~30d,终生都在小孢子壁内发育。(2)雄配子体只含有1个原叶体细胞、1个精子器壁细胞和4个精细胞,前2个细胞内含有丰富的营养物质。(3)精子由精核、微管带、鞭毛、细胞质等4部分构成。(4)中华水韭雄配子体发生率为4.5%,平均每个雄配子体产生0.46个精子,精子游动速度约53μm/s,寿命8min;云贵水韭雄配子体发生率和产精量略高于中华水韭,但精子游动速度和寿命略低于中华水韭。研究认为,中国水韭濒危的主要原因之一是雄配子体产精率低、受到生殖生态限制、水污染对精子的危害等;雄性特征表明水韭在石松类中占有较高的进化地位;结合前人的研究成果绘出了水韭雄配子体的发育模式。     

Converting Endangered Species Categories to Probabilities of Extinction for Phylogenetic Conservation Prioritization

Background

Categories of imperilment like the global IUCN Red List have been transformed to probabilities of extinction and used to rank species by the amount of imperiled evolutionary history they represent (e.g. by the Edge of Existence programme). We investigate the stability of such lists when ranks are converted to probabilities of extinction under different scenarios.

Methodology and Principal Findings

Using a simple example and computer simulation, we show that preserving the categories when converting such list designations to probabilities of extinction does not guarantee the stability of the resulting lists.

Significance

Care must be taken when choosing a suitable transformation, especially if conservation dollars are allocated to species in a ranked fashion. We advocate routine sensitivity analyses.     

三峡库区消涨带特有濒危植物丰都车前Plantago fengdouensis的迁地保护

丰都车前(Plantago fengdouensis)为近年在三峡库区消涨带发现的一特有植物。通过多年的调查,发现该种仅分布于重庆市忠县、丰都县和巴南区等3个长江江心岛上,总共290株。随着三峡水库的逐步蓄水,丰都车前的自然分布区将于2006年全部水淹,使其成为因三峡工程建设而导致自然生境和野生居群全部毁灭的唯一的草本植物。为保护这一即将野外灭绝的稀有植物,在对其地理分布、生态学和群落学调查的基础上,对其形态特征、年生长周期和生殖值与同属植物车前(P.asiatica)和北美车前(P.virginica)进行了调查、试验和比较研究,表明丰都车前果期长、种子不适宜长距离传播和生殖值低以及长江水淹干扰是其狭域分布和数量稀少的主要原因。同时探讨了其迁地保护策略,并提出了下一步的研究和保护建议。     

中国特有濒危种川东灯台报春(报春花科)的重新发现

2006年6月份和9月份,作者在对重庆市城口县大巴山地区进行考察时,采集到了中国特有种川东灯台报春（Primula mallophylla）的标本,这是近百年来对该种除模式标本外的再度发现。根据在大巴山观察及采集到的材料,作者对过去该种的特征描述中存在的一些疑问进行了澄清,更正和补充了其形态描述;对历史上混淆的几个种列出了检索表;报道了该种的染色体数目及核型;根据国际通用的“红色名录等级及标准”对其濒危等级进行了评估。     

中国特有濒危种川东灯台报春( 报春花科) 的重新发现

2006 年6 月份和9 月份, 作者在对重庆市城口县大巴山地区进行考察时, 采集到了中国特有种川东灯台报春( Primula mallophylla) 的标本, 这是近百年来对该种除模式标本外的再度发现。根据在大巴山观察及采集到的材料, 作者对过去该种的特征描述中存在的一些疑问进行了澄清, 更正和补充了其形态描述; 对历史上混淆的几个种列出了检索表; 报道了该种的染色体数目及核型; 根据国际通用的“红色名录等级及标准”对其濒危等级进行了评估。     

Patterns of Genetic Variation in Swertia przewalskii, an Endangered Endemic Species of the Qinghai-Tibet Plateau

Swertia przewalskii Pissjauk. (Gentianaceae) is a critically endangered and endemic plant of the Qinghai-Tibet Plateau in China. RAPD and ISSR analyses were carried out on a total of 63 individuals to assess the extent of genetic variation in the remaining three populations. Percentage of polymorphic bands was 94% (156 bands) for RAPD and 96% (222 bands) for ISSR. A pairwise distance measure calculated from the RAPD and ISSR data was used as input for analysis of molecular variance (AMOVA). AMOVA indicated that a high proportion of the total genetic variation (52% for RAPD and 56% for ISSR) was found among populations; pairwise Φ _ST comparisons showed that the three populations examined were significantly different (p < 0.001). Significant genetic differentiation was found based on different measures (AMOVA and Hickory θ_B) in S. przewalskii (0.52 on RAPD and 0.56 on ISSR; 0.46 on RAPD and 0.45 on ISSR). The differentiation of the populations corresponded to low average gene flow (0.28 based on RAPD and 0.31 based on ISSR), whereas genetic distance-based clustering and coalescent-based assignment analyses revealed significant genetic isolation among populations. Our results indicate that genetic diversity is independent of population size. We conclude that although sexual reproduction and gene flow between populations of S. przewalskii are very limited, they have preserved high levels of genetic diversity. The main factors responsible for the high level of difference among populations are the isolation and recent fragmentation under human disturbance.     

Unveiling the Conservation Biogeography of a Data-Deficient Endangered Bird Species under Climate Change

It remains a challenge to identify the geographical patterns and underlying environmental associations of species with unique ecological niches and distinct behaviors. This in turn hinders our understanding of the ecology as well as effective conservation management of threatened species. The white-eared night heron (Gorsachius magnificus) is a non-migratory nocturnal bird species that has a patchy distribution in the mountainous forests of East Asia. It is currently categorized as “Endangered” on the IUCN Red List, primarily due to its restricted range and fragmented habitat. To improve our knowledge of the biogeography and conservation of this species, we modeled the geographical pattern of its suitable habitat and evaluated the potential impacts of climate change using ecological niche modeling with a maximum entropy approach implemented in Maxent. Our results indicated that the amount of suitable habitat in all of East Asia was about 130 000 km², which can be spatially subdivided into several mountain ranges in southern and southwestern China and northern Vietnam. The extent of suitable habitat range may shrink by more than 35% under a predicted changing climate when assuming the most pessimistic condition of dispersal, while some more suitable habitat would be available if the heron could disperse unrestrainedly. The significant future changes in habitat suitability suggested for Gorsachius magnificus urge caution in any downgrading of Red List status that may be considered. Our results also discern potentially suitable areas for future survey efforts on new populations. Overall, this study demonstrates that ecological niche modeling offers an important tool for evaluating the habitat suitability and potential impacts of climate change on an enigmatic and endangered species based on limited presence data.     

两种濒危水韭植物迁地保护居群的基因流动态及回归重建保育遗传管理策略

采用微卫星分子标记对中华水韭（Isoetessinensis）安徽休宁、浙江建德和东方水韭（I.orientalis）浙江松阳三个孑遗居群的迁地保护居群开展了遗传多样性检测与遗传结构分析。7对多态性微卫星引物在36个迁地保护亚居群的720个样本中共检测到59个等位基因,每位点平均等位基因数（A）为8·43。迁地保护亚居群均维持很高的遗传多样性,多态信息含量（PIC）平均为0·707。迁地保护亚居群间遗传分化较低,遗传分化系数GST仅为0·070,居群间具有较大基因流（Nm=3·59）。单因素方差分析发现水韭孢子或孢子体在沿主要水流方向上的长距离传播能力要强于弱水流方向上的短距离传播能力,水流动态对水韭植物的基因流有重要影响。这与UPGMA聚类分析中迁地保护亚居群按邻近位置或水流相通程度优先聚类的结果相一致,水流所带动的强大基因流导致了不同孑遗居群来源的迁地保护亚居群间的遗传混杂。建议在开展水韭植物的迁地保护或回归自然重建时,对具有地方适应分化或者显著性进化的水韭植物居群应相互隔离而不宜配置在一起,以避免远交衰退的遗传风险。     

Mitochondrial DNA Genetic Diversity of Black Muntjac (Muntiacus crinifrons), An Endangered Species Endemic to China

Genetic diversities based on the mtDNA control region were measured for both a wild population (n = 26) and a captive population (n = 18) of the black muntjac. In total, nine haplotypes were obtained from 44 samples. The wild population exhibited a low nucleotide diversity (π = 0.00562), which suggests that the black muntjac had a small effective population size historically. In contrast to its low nucleotide diversity, haplotype diversity (h = 0.862) of the wild population was relatively high. Haplotype distribution among local samples shows a distinct difference. As anticipated because of the paucity of available founders, nucleotide diversity (π = 0.00214) of the captive population was very low. Additionally, a high degree of haplotype identity and an obvious haplotype frequency bias was revealed in the captive population, which implies that the current breeding program should be readjusted to balance distributions of haplotypes, and some new founders should be introduced to the captive population to alleviate potential inbreeding depression.     

Biology and Egg Morphology of The Dalmatian Barbelgudgeon Aulopyge Huegeli, An Endangered Endemic Species in Croatia

This paper describes patterns of annual and diurnal activity in the endangered endemic cyprinid Aulopyge huegeli from Croatia. The species is largely nocturnal. Spawning in the laboratory begins at temperatures of 20°C. Aulopyge huegeli is a rock and gravel brood hider. The female deposits eggs in various fissures with a special ovipositor. The eggs are whitish and have a diameter between 1.5 and 2mm. The zona radiata is relatively thin (3.2–5.5m) and provides the eggs with the necessary plasticity. The surface is covered with an attaching substance and with short attachment extension around the vegetal pole. This correlates with features of the spawning microhabitats. Aulopyge huegeli has a very small micropyle which consists of a pit with a diameter of 7.5m and a canal with a diameter of 2.5m (micropyle type I).     

Studies on the Reproductive Characteristics of Cimicifuga nanchuanensis (Ranunculaceae), an Endemic Endangered Species to China

Aspects of the reproductive biology of Cimicifuga nanchuanensis Hsiao have been studied to shed light on the endangerment of this species, endemic to Jingfo Mountain in Sichuan Province of China. The only one population of C. nanchuanensis includes 6 000 ~ 8 000 individuals, in which adult blooming plants accoum for 19%. Inflorescence is panicle,flowering period lasts from mid August to early October and fruits ripe in mid or late November. C. nanchuanensis is dichogamous and the stigmas mature 7 days after withering of flower. In natural conditions the rate of seed-setting is 5.8% ~ 7.0% in average. However, hand pollination can raise the rate greatly to 28.0%. Endosperm type is nuclear and embryos are just at the globular stage when seeds shed from their maternal plants. Pollen limitation is one of the reasons for this species endangerment.     

A Study of Conservation Genetics in Cupressus chengiana,an Endangered Endemic of China,Using ISSR Markers

ISSR markers were used to analyze the genetic diversity and genetic structure of eight natural populations of Cupressus chengiana in China. ISSR analysis using 10 primers was carried out on 92 different samples. At the species level, 136 polymorphic loci were detected. The percentage of polymorphic bands (PPB) was 99%. Genetic diversity (H _e) was 0.3120, effective number of alleles (A _e) was 1.5236, and Shannon’s information index (I) was 0.4740. At the population level, PPB = 48%, A _e=1.2774, H _e=0.1631, and I=0.2452. Genetic differentiation (G _st) detected by Nei’s genetic diversity analysis suggested 48% occurred among populations. The partitioning of molecular variance by AMOVA analysis indicated significant genetic differentiation within populations (54%) and among populations (46%; P < 0.0003). The average number of individuals exchanged between populations per generation (N _m ) was 0.5436. Samples from the same population clustered in the same population-specific cluster, and two groups of Sichuan and Gansu populations were distinguishable. A significantly positive correlation between genetic and geographic distance was detected (r=0.6701). Human impacts were considered one of the main factors to cause the rarity of C. chengiana, and conservation strategies are suggested based on the genetic characters and field investigation, e.g., protection of wild populations, reestablishment of germplasm bank, and reintroduction of more genetic diversity.