Molecular Systematics of Threatened Seed Plant Species Endemic in the Caribbean Islands

A review of available Caribbean Island red-lists species (CR and EN categories based on the IUCN guidelines from 2001, and E category established according to the IUCN guidelines from 1980) is presented. A database of over 1,300 endemic species that are either Critically Endangered or Endangered sensu IUCN was created. There are molecular systematic studies available for 112 of them. Six of these species (in six genera) are the only members of early divergent lineages that are sister to groups composed of a large number of clades. Seven of the species (in seven genera) belong to clades that have a small number of taxa but are sister to species/genus-rich clades. Ten of the species (in six genera) are sister to taxa restricted to South America or nested in clades endemic to this region. Fifty-seven of the species (in 35 genera) are sister to Caribbean Island endemic species. Erigeron belliastroides, an Endangered (EN) Cuban endemic, is sister to the Galapagos genus Darwiniothamnus. The phylogenetic placement of four of the threatened species resulted in changes in their taxonomic placement; they belong to polyphyletic or paraphyletic genera.     

Evaluating Genetic Diversity for the Conservation of the Threatened Galapagos Endemic Calandrinia galapagosa (Portulacaceae)

Calandrinia galapagosa (Portulacaceae) is a threatened plant endemic to San Cristobal Island, Galapagos. The species is threatened by goat herbivory: less than 1300 individuals remain in nine populations, three of which have been fenced for protection. It is not known whether these three populations are genetically representative of the species at large or whether the three distinct color morphs exhibited by the species represent different taxonomic units. We measured the frequency of 113 polymorphic amplified fragment length polymorphism markers in 189 specimens representing three different phenotypes from all nine populations to relate the genetic structure of the species to both its geological history and morphological variation. The analysis revealed high diversity within populations and low, but significant, differentiation between populations. In addition, no genetic diversification was observed across color morphs. We conclude that (1) regular gene flow has historically occurred between populations, and (2) individual color morphs are not separate taxa. We identify another population that should be fenced to ensure maximal protection of genetic variation. Our research serves as a case study of using population molecular genetics for optimizing protection strategies for rare plants in tropical archipelagoes affected by introduced herbivores.     

Genetic Structure of Threatened Native Populations and Propagules Used for Restoration in a Clonal Species,American Beachgrass (Ammophila breviligulata Fern.)

An important goal of native plant restorations was to reconstitute populations that are genetically similar to native ones, thereby increasing the probably of successful establishment and persistence. We examined the extent to which this goal has been accomplished in Great Lakes restorations of Ammophila breviligulata Fern., a beachgrass species that is widely used for habitat restoration and is considered threatened in the study areas. In parallel studies on Lake Michigan and Lake Superior, we used polymorphic Intersimple Sequence Repeat markers to assess genetic similarity between well‐established and new native populations, restored populations, and restoration propagules obtained from two commercial suppliers. Native populations were generally more diverse than expected for a clonal species, whereas the commercially cultivated releases were monotypic. One of the commercial releases used in Minnesota was exclusively found in restored populations and did not occur in any other native population at this site. The propagules used in the newly planted restoration in Illinois were derived from a release that commercial suppliers maintain was derived from a native Michigan population, as opposed to a selected release. Diversity in this restoration was equivalent to that native Illinois’ populations; however, many of the genotypes were not of local origin. Overall, study underscores the importance of obtaining baseline genetic surveys of remnant native populations and restoration propagules before restoration efforts are initiated, especially when the populations are threatened or endangered.     

Endemic Asian Chytrid Strain Infection in Threatened and Endemic Anurans of the Northern Western Ghats,India

The Western Ghats of India harbors a rich diversity of amphibians with more than 77% species endemic to this region. At least 42% of the endemic species are threatened due to several anthropogenic stressors. However, information on amphibian diseases and their impacts on amphibian populations in this region are scarce. We report the occurrence of Batrachochytridium dendrobatidis (Bd), an epidermal aquatic fungal pathogen that causes chytridiomycosis in amphibians, from the Western Ghats. In the current study we detected the occurrence of a native Asian Bd strain from three endemic and threatened species of anurans, Bombay Night Frog Nyctibatrachus humayuni, Leith''s Leaping Frog Indirana leithii and Bombay Bubble Nest Frog Raorchestes bombayensis, for the first time from the northern Western Ghats of India based on diagnostic nested PCR, quantitative PCR, DNA sequencing and histopathology. While, the Bd infected I. leithii and R. bombayensis did not show any external symptoms, N. humayuni showed lesions on the skin, browning of skin and sloughing. Sequencing of Bd 5.8S ribosomal RNA gene, and the ITS1 and ITS2 regions, revealed that the current Bd strain is related to a haplotype endemic to Asia. Our findings confirm the presence of Bd in northern Western Ghats and the affected amphibians may or may not show detectable clinical symptoms. We suggest that the significance of diseases as potential threat to amphibian populations of the Western Ghats needs to be highlighted from the conservation point of view.     

中国特有濒危植物伯乐树根的生态解剖学研究

伯乐树（Bretschneidera sinensis Hemsl.）是中国特有濒危的第三纪孑遗植物。本研究采用石蜡切片、整体封片、扫描电镜和激光共聚焦扫描等技术研究其根的表面特征和形态结构,从生态解剖学角度揭示其对生境的适应和特殊要求。结果显示伯乐树作为特殊的菌根型木本植物,根尖表面无根毛分化;初生结构包括表皮、皮层和中柱三部分,系原始的发育类型,其皮层明显排列为两轮且存在自然的间隙,皮层内有含黑芥子酶的分泌细胞,中柱内有髓。菌根菌以单菌丝或菌丝网侵入根表皮,并刺激表皮分泌沉积了较厚的无定形物质,入侵后可在皮层间隙内大量分枝,还能进一步形成泡囊结构;菌根菌在寄主细胞内常包围在淀粉粒的周围吸收营养,同时部分菌丝在细胞内被分解形成小泡和碎屑,为寄主细胞提供营养以形成共生关系。根据以上特征,应在就地保护和迁地保育中深入研究适宜伯乐树的土壤条件,以促进菌根的发生和发育。     

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.     

特有珍稀濒危植物景东报春遗传多样性的ISSR分析(英文)

景东报春(Primula interjacens Chen)是一分布在中国云南中南部的稀有的、分布区狭窄的特有种。该种含2个变种:原变种景东报春(P.interjacens Chen var.interjacens),现存一个居群;和光叶景东报春(P.interjacens Chen var.epilosa C.M.Hu),有2个居群。本文用ISSR分子标记对景东报春现存的3个居群进行了遗传多样性分析。和我们最初的预计相反,尽管居群小、分布区狭窄,景东报春的遗传多样性却很高(在居群水平的多态位点率P=59.75％,基因多样性H_E=0.2368,Hpop=0.3459:在种的水平的多态位点率P=75.47％,遗传多样性H_T=0.3205,总的遗传多样性Hsp=0.4618)。推测异型花和杂交可能是维持高的遗传多样性的原因。Nei的遗传多样性水平(26.13％)和Shannon多样性指数(25.09％)显示居群间存在中度分化。尽管景东报春原变种和变种在形态上有区别,但用非加权配对算数平均法(UPGMA)聚类分析的结果表明,两者并没有明显的遗传分化,可处理为一个单一的分类单元。基于观察到的居群遗传信息,建议采取就地保护和迁地保护的保护措施。     

Loss of Genetic Diversity and Increased Subdivision in an Endemic Alpine Stonefly Threatened by Climate Change

Much remains unknown about the genetic status and population connectivity of high-elevation and high-latitude freshwater invertebrates, which often persist near snow and ice masses that are disappearing due to climate change. Here we report on the conservation genetics of the meltwater stonefly Lednia tumana (Ricker) of Montana, USA, a cold-water obligate species. We sequenced 1530 bp of mtDNA from 116 L. tumana individuals representing “historic” (>10 yr old) and 2010 populations. The dominant haplotype was common in both time periods, while the second-most-common haplotype was found only in historic samples, having been lost in the interim. The 2010 populations also showed reduced gene and nucleotide diversity and increased genetic isolation. We found lower genetic diversity in L. tumana compared to two other North American stonefly species, Amphinemura linda (Ricker) and Pteronarcys californica Newport. Our results imply small effective sizes, increased fragmentation, limited gene flow, and loss of genetic variation among contemporary L. tumana populations, which can lead to reduced adaptive capacity and increased extinction risk. This study reinforces concerns that ongoing glacier loss threatens the persistence of L. tumana, and provides baseline data and analysis of how future environmental change could impact populations of similar organisms.     

Genetic structure of Atriplex halimus populations in the Mediterranean Basin

BACKGROUND AND AIMS: The saltbush Atriplex halimus is a chenopodiaceous plant well adapted to dry saline habitats and widely distributed in the Mediterranean Basin. A study was carried out to analyse the genetic diversity of A. halimus at the level of the Mediterranean Basin. METHODS: To assess the intra- and interpopulational variation of A. halimus a total of 51 populations and six plants per populations was analysed with the RAPD-PCR technique. For the study of the phylogeny of the populations, 21 samples of A. halimus and seven samples of other species of Atriplex were analysed by the sequencing of the ITS (internal transcribed spacer) region of the ribosomal DNA. KEY RESULTS: The AMOVA analysis of the RAPD results showed that populations were divided into two discrete genetic groups, as the variation among groups accounted for 54.36 % of the total variance of the collection. At the same time, the intrapopulational diversity was high, as 301 out of 306 plants analysed constituted an individual RAPD haplotype. The sequencing of the ITS region also showed a significant separation of the two genetic groups, with a genetic distance of 0.023 nucleotide substitutions per site. Using A. breweri, A. canescens, A. glauca and A. prostrata as outgroups in the phylogenetic analysis, A. breweri and A. canescens are the species closest to A. halimus from this group, while A. prostrata is the most distant. CONCLUSIONS: The present work indicates that two genetic groups of A. halimus can be distinguished after analysing the genetic diversity of 51 populations from ten countries in the Mediterranean Basin.     

特有珍稀濒危植物景东报春遗传多样性的ISSR分析

景东报春(Primula interjacens Chen)是一分布在中国云南中南部的稀有的、分布区狭窄的特有种.该种含2个变种:原变种景东报春(P.interjacens Chen var.interjacens),现存一个居群;和光叶景东报春(P.interjacens Chen var.epilosa C.M.Hu),有2个居群.本文用ISSR分子标记对景东报春现存的3个居群进行了遗传多样性分析.和我们最初的预计相反,尽管居群小、分布区狭窄,景东报春的遗传多样性却很高(在居群水平的多态位点率P=59.75%,基因多样性HE=0.236 8,Hpop=0.345 9;在种的水平的多态位点率P=75.47%,遗传多样性HT=0.320 5,总的遗传多样性Hsp=0.4618).推测异型花和杂交可能是维持高的遗传多样性的原因.Nei的遗传多样性水平(26.13%)和Shannon多样性指数(25.09%)显示居群间存在中度分化.尽管景东报春原变种和变种在形态上有区别,但用非加权配对算数平均法(UPGMA)聚类分析的结果表明,两者并没有明显的遗传分化,可处理为一个单一的分类单元.基于观察到的居群遗传信息,建议采取就地保护和迁地保护的保护措施.     

Fine‐scale Spatial Genetic Structure of Ten Dipterocarp Tree Species in a Bornean Rain Forest

Fine‐scale spatial genetic structure is increasingly recognized as an important factor in the studies of tropical forest trees as it influences genetic diversity of local populations. The biologic mechanisms that generate fine‐scale spatial genetic structure are not fully understood. We studied fine‐scale spatial genetic structure in ten coexisting dipterocarp tree species in a Bornean rain forest using microsatellite markers. Six of the ten species showed statistically significant fine‐scale spatial genetic structure. Fine‐scale spatial genetic structure was stronger at smaller spatial scales (≤ 100 m) than at larger spatial scales (> 100 m) for each species. Multiple regression analysis suggested that seed dispersal distance was important at the smaller spatial scale. At the larger scale (> 100 m) and over the entire sample range (0–1000 m), pollinators and spatial distribution of adult trees were more important determinants of fine‐scale spatial genetic structure. Fine‐scale spatial genetic structure was stronger in species pollinated by less mobile small beetles than in species pollinated by the more mobile giant honeybee (Apis dorsata). It was also stronger in species where adult tree distributions were more clumped. The hypothesized mechanisms underlying the negative correlation between clump size and fine‐scale spatial genetic structure were a large overlap among seed shadows and genetic drift within clumped species.     

Combining Genetic and Demographic Data for the Conservation of a Mediterranean Marine Habitat-Forming Species

The integration of ecological and evolutionary data is highly valuable for conservation planning. However, it has been rarely used in the marine realm, where the adequate design of marine protected areas (MPAs) is urgently needed. Here, we examined the interacting processes underlying the patterns of genetic structure and demographic strucuture of a highly vulnerable Mediterranean habitat-forming species (i.e. Paramuricea clavata (Risso, 1826)), with particular emphasis on the processes of contemporary dispersal, genetic drift, and colonization of a new population. Isolation by distance and genetic discontinuities were found, and three genetic clusters were detected; each submitted to variations in the relative impact of drift and gene flow. No founder effect was found in the new population. The interplay of ecology and evolution revealed that drift is strongly impacting the smallest, most isolated populations, where partial mortality of individuals was highest. Moreover, the eco-evolutionary analyses entailed important conservation implications for P. clavata. Our study supports the inclusion of habitat-forming organisms in the design of MPAs and highlights the need to account for genetic drift in the development of MPAs. Moreover, it reinforces the importance of integrating genetic and demographic data in marine conservation.     

Genetic Diversity and Genetic Structure of an Endangered Species, Trillium tschonoskii

The genetic diversity and genetic structure of Trillium tschonoskii (Maxim) were investigated using amplified fragment length polymorphism markers. Eight primer combinations were carried out on 105 different individuals sampled from seven populations. Of the 619 discernible DNA fragments generated, 169 (27.3%) were polymorphic. The percentage of polymorphic bands within populations ranged from 4.52 to 10.50. Genetic diversity (H_E) within populations ranged from 0.0130 to 0.0379, averaging 0.0536 at the species level. Genetic differentiation among populations was detected based on Nei's genetic diversity analysis (53.03%) and analysis of molecular variance (AMOVA) (52.43%). AMOVA indicated significant genetic differentiation among populations (52.43% of the variance) and within populations (47.57% of the variance) (p < 0.0002). Gene flow was low (0.4429) among populations. Species breeding system and limited gene flow among populations are plausible reasons for the high genetic differentiation observed for this species. We propose an appropriate strategy for conserving the genetic resources of T. tschonoskii in China.     

Population Genetic Structure of a Microalgal Species under Expansion

Biological invasions often cause major perturbations in the environment and are well studied among macroorganisms. Less is known about invasion by free-living microbes. Gonyostomum semen (Raphidophyceae) is a freshwater phytoplankton species that has increased in abundance in Northern Europe since the 1980''s and has expanded its habitat range. In this study, we aimed to determine the genetic population structure of G. semen in Northern Europe and to what extent it reflects the species'' recent expansion. We sampled lakes from 12 locations (11 lakes) in Norway, Sweden and Finland. Multiple strains from each location were genotyped using Amplified Fragment Length Polymorphism (AFLP). We found low differentiation between locations, and low gene diversity within each location. Moreover, there was an absence of genetic isolation with distance (Mantel test, p = 0.50). According to a Bayesian clustering method all the isolates belonged to the same genetic population. Together our data suggest the presence of one metapopulation and an overall low diversity, which is coherent with a recent expansion of G. semen.     

Microsatellite Markers Reveal Strong Genetic Structure in the Endemic Chilean Dolphin

Understanding genetic differentiation and speciation processes in marine species with high dispersal capabilities is challenging. The Chilean dolphin, Cephalorhynchus eutropia, is the only endemic cetacean of Chile and is found in two different coastal habitats: a northern habitat with exposed coastlines, bays and estuaries from Valparaíso (33°02′S) to Chiloé (42°00′S), and a southern habitat with highly fragmented inshore coastline, channels and fjords between Chiloé and Navarino Island (55°14′S). With the aim of evaluating the potential existence of conservation units for this species, we analyzed the genetic diversity and population structure of the Chilean dolphin along its entire range. We genotyped 21 dinucleotide microsatellites for 53 skin samples collected between 1998 and 2012 (swab: n = 8, biopsy: n = 38, entanglement n = 7). Bayesian clustering and spatial model analyses identified two genetically distinct populations corresponding to the northern and southern habitats. Genetic diversity levels were similar in the two populations (He: 0.42 v/s 0.45 for southern and northern populations, respectively), while effective size population was higher in the southern area (Ne: 101 v/s 39). Genetic differentiation between these two populations was high and significant (F_ST = 0.15 and R_ST = 0.19), indicating little or no current gene flow. Because of the absence of evident geographical barriers between the northern and southern populations, we propose that genetic differentiation may reflect ecological adaptation to the different habitat conditions and resource uses. Therefore, the two genetic populations of this endemic and Near Threatened species should be considered as different conservation units with independent management strategies.     

The Rules of Aggression: How Genetic,Chemical and Spatial Factors Affect Intercolony Fights in a Dominant Species,the Mediterranean Acrobat Ant Crematogaster scutellaris

Nest-mate recognition plays a key role in the biology of ants. Although individuals coming from a foreign nest are, in most cases, promptly rejected, the degree of aggressiveness towards non nest-mates may be highly variable among species and relies on genetic, chemical and environmental factors. We analyzed intraspecific relationships among neighboring colonies of the dominant Mediterranean acrobat ant Crematogaster scutellaris integrating genetic, chemical and behavioral analyses. Colony structure, parental relationships between nests, cuticular hydrocarbons profiles (CHCs) and aggressive behavior against non nest-mates were studied in 34 nests located in olive tree trunks. Bayesian clustering analysis of allelic variation at nine species-specific microsatellite DNA markers pooled nests into 14 distinct clusters, each representing a single colony, confirming a polydomous arrangement of nests in this species. A marked genetic separation among colonies was also detected, probably due to long distance dispersion of queens and males during nuptial flights. CHCs profiles varied significantly among colonies and between nests of the same colony. No relationship between CHCs profiles and genetic distances was detected. The level of aggressiveness between colonies was inversely related to chemical and spatial distance, suggesting a ‘nasty neighbor’ effect. Our findings also suggest that CHCs profiles in C. scutellaris may be linked to external environmental factors rather than genetic relationships.     

Allozyme Variation and the Genetic Structure of Populations of Trochodendron aralioides, a Monotypic and Narrow Geographic Genus

Trochodendron aralioides Siebold & Zucc., a primitive angiosperm that is insect-pollinated, has wind-dispersed seeds and grows only in eastern Asia. Nineteen populations were analyzed, including 16 from Taiwan, two from the main islands of Japan and one from Iriomote Island in the Ryukyu Islands. Genetic variability (0.133) at the species level was more similar to that of a narrow geographic species than an endemic species. Based on genotype frequencies, mating within populations was non-random (F _{I s}=0.065) and there was significant genetic differentiation (F _ST =0.164) among populations. Genetic diversity was largely within, rather than among, populations (H _s =0.132, 85.14%). Bisexual flowers of T. aralioides exhibit synchronized dimorphism. The protogynous and protandrous morphs are self-incompatible, which probably promotes outcrossing and contributes to the high levels of heterozygosity within populations. Using a maximum likelihood tree, populations of T. aralioides were separated into two distinct clusters: Japan and Taiwan/ Iriomote Island. Populations of T. aralioides on Iriomote Island and in northern Taiwan exhibited a high degree of genetic similarity. The isolation-by-distance model does not fit populations in Taiwan, but suitably describes the relationship between populations of T. aralioides in Japan and Taiwan. Received 28 April 2000/ Accepted in revised form 13 December 2000     

Genetic Variation in Chinese Pine (Pinus tabulaeformis), a Woody Species Endemic to China

Random amplified polymorphic DNA markers were used to investigate genetic variation of the Chinese pine (Pinus tabulaeformis Carr.), a species endemic to China and the most widely distributed pine species in North China. The results revealed that P. tabulaeformis populations had a relatively high level of genetic diversity (H _t = 0.3268), distributed mainly within (79.2%) rather than among (20.8%) populations. The populations of Lingkong Mountain and Wuling Mountain had a higher level of diversity (0.2687) than the other four populations (0.2537). No statistically significant relationships were found between genetic diversity and climatic factors by correlation analysis and between genetic distance and geographic distance by the Mantel test. These results suggest that the partitioning of genetic diversity in each population might have been influenced not only by water and temperature conditions but also by other factors such as human activities and the Holocene postglacial history of these populations.     

Genetic isolation of insular populations of the Maghrebian bat,Myotis punicus,in the Mediterranean Basin

Aim We investigate the population genetic structure of the Maghrebian bat, Myotis punicus, between the mainland and islands to assess the island colonization pattern and current gene flow between nearby islands and within the mainland. Location North Africa and the Mediterranean islands of Corsica and Sardinia. Methods We sequenced part of the control region (HVII) of 79 bats across 11 colonies. The phylogeographical pattern was assessed by analysing molecular diversity indices, examining differentiation among populations and estimating divergence time. In addition, we genotyped 182 bats across 10 colonies at seven microsatellite loci. We used analysis of molecular variance and a Bayesian approach to infer nuclear population structure. Finally, we estimated sex‐specific dispersal between Corsica and Sardinia. Results Mitochondrial analyses indicated that colonies between Corsica, Sardinia and North Africa are highly differentiated. Within islands there was no difference between colonies, while at the continental level Moroccan and Tunisian populations were highly differentiated. Analyses with seven microsatellite loci showed a similar pattern. The sole difference was the lack of nuclear differentiation between populations in North Africa, suggesting a male‐biased dispersal over the continental area. The divergence time of Sardinian and Corsican populations was estimated to date back to the early and mid‐Pleistocene. Main conclusions Island colonization by the Maghrebian bats seems to have occurred in a stepping‐stone manner and certainly pre‐dated human colonization. Currently, open water seems to prevent exchange of bats between the two islands, despite their ability to fly and the narrowness of the strait of Bonifacio. Corsican and Sardinian populations are thus currently isolated from any continental gene pool and must therefore be considered as different evolutionarily significant units (ESU).     

祁连山区特有物种黑虎耳草的居群遗传多样性研究

利用叶绿体基因(rbcL和trnS-G)及核糖体DNA内转录间隔区(ITS),对祁连山区狭域分布的特有物种黑虎耳草8个居群(115个个体)进行遗传多样性研究,旨在揭示黑虎耳草的居群遗传结构及其历史进化过程。结果表明:(1)所有取样个体共检测到4个cpDNA单倍型和9个ITS单倍型,其中祁连山东南部的居群固定较多的单倍型和特有单倍型,而西北部居群只固定少数几个广泛分布的单倍型,且遗传多样性普遍较低。(2)基于cpDNA数据和ITS数据的分子变异分析(AMOVA)显示,遗传变异主要来源于居群内。(3)基于cpDNA数据的中性检验表明,Tajima’s D(-1.012 30,P> 0.05)和Fu&Li’s D*(-2.066 77,P> 0.05)均为负值,均不显著;歧点分布分析结果显示,黑虎耳草居群经历过近期的扩张事件。根据物种现有遗传分布格局推测,黑虎耳草在第四纪冰期时退缩到祁连山东南部的边缘避难所,间冰期或冰期后回迁到祁连山西北部地区,在回迁过程中由于奠基者效应导致祁连山西北部的居群仅固定少数广泛分布的单倍型,并呈现出较低的遗传多样性;由于居群较小且相互隔离,该...