Genetic diversity and population structure of the endangered ripon barbel,Barbus altianalis (Boulenger, 1900) in Lake Victoria catchment,Kenya based on mitochondrial DNA sequences

Approximately 850 bp of the mitochondrial control region was used to assess the genetic diversity, population structure and demographic expansion of the endangered cyprinid Barbus altianalis, a species known to be potamodramous in the Lake Victoria drainage system. The 196 samples taken from the four main rivers draining the Lake Victoria catchment (Nzoia, Yala, Nyando and Sondu–Miriu) yielded 49 mitochondrial DNA haplotypes; 83.7% thereof were private haplotypes restricted to particular rivers. The overall mean haplotype diversity was high (0.93663 ± 0.008) and ranged between 0.566 (Sondu – Miriu) and 0.944 (Nzoia). The overall mean nucleotide diversity was low (0.01322 ± 0.00141), ranging from 0.0342 (Sondu – Miriu) to 0.0267 (Nzoia). Population differentiation tests revealed strong and highly significant (P ≤ 0.001) segregation of populations in the four river basins. F_ST values among the four river‐based populations ranged from 0.05202 to 0.44352. The samples formed two main haplotype networks based on a 95% parsimony criterion, each exhibiting a strong signature of past population expansion. The smaller network was restricted to the River Nzoia, whereas the larger network contained representatives from all four rivers; within this the central haplotypes were found in more than one river, whereas the peripheral haplotypes tended to be river‐specific. The degree of population differentiation and the number of river‐specific haplotypes are too high to be explained by recent anthropogenic impacts alone and suggest that the species has probably existed in the Lake Victoria catchment as two populations: the now ‘extinct’ migratory population and the extant river restricted non‐migratory populations.     

Genetic structure and gene flow in an endangered native tilapia fish (Oreochromis esculentus) compared to invasive Nile tilapia (Oreochromis niloticus) in Yala swamp, East Africa

The introduction of invasive Nile tilapia (Oreochromis niloticus), and the rapacious predator Nile perch (Lates niloticus), into Lake Victoria resulted in a decline in population sizes, genetic diversity and even extirpation of native species which were previously the mainstay of local fisheries. However, remnant populations of native fish species, including tilapia, still persist in satellite lakes around Lake Victoria where they may coexist with O. niloticus. In this study we assessed population genetic structure, diversity, and integrity of the native critically endangered Singidia tilapia (O. esculentus) in its refugial populations in the Yala swamp, Kenya, and contrasted this diversity with populations of the invasive tilapia O. niloticus in satellite lakes (Kanyaboli, Namboyo and Sare) and Lake Victoria. Based on mtDNA control region sequences and eight nuclear microsatellite loci, we did not detect any mtDNA introgression between the native and the invasive species in Lakes Kanyaboli and Namboyo, but did find low levels of nuclear admixture, primarily from O. niloticus to O. esculentus. Some genetic signal of O. esculentus in O. niloticus was found in Lake Sare, where O. esculentus is not found, suggesting it has recently been extirpated by the O. niloticus invasion. In both species, populations in the satellite lakes are significantly genetically isolated from each other, with private mtDNA haplotypes and microsatellite alleles. For O. niloticus, genetic diversity in satellite lakes was similar to that found in Lake Victoria. Our data imply a low frequency of immigration exchange between the two populations of O. esculentus and we suggest that the populations of this endangered species and important fisheries resource should be conserved separately in Lakes Kanyaboli and Namboyo and with high priority.     

Impact of rifting and hydrography on the genetic structure of Clarias gariepinus in eastern Africa

In a study of the genetic structure of Clarias gariepinus at the ND5 and ND6 loci of mitochondrial DNA using RFLP–PCR in 16 populations (267 fish), a total of 18 haplotypes was detected. The most common haplotype was EA1 and represented 46% of all genotypes. Three phylogenetic groups characterized the region, with the East African clade occurring between the western rift in the west, Lake Baringo in the north, the Indian Ocean in the east and the Rufiji River in the south. The Lower Tana River (unlike the Upper Tana River) and Lake Kamnarok grouped with the North clade, while the Ruaha River (tributary of the Rufiji River) represented a contact zone between the East and the South-central African clade. Genetic structure was distinct ( F _ST=0·66), with the Lower Tana River and Lake Mtera forming specific units. Within the East clade, the Oloibortoto River, Upper Tana River and Lake Victoria each formed a distinct population. Lake Baringo grouped either with the eastern rift or the western rift depending on the analysis. Lake Jipe, the Pangani River, Rusizi River, Lake Edward, Nyabugogo River and the Luiche River clustered together. Among group variance explained 66·8% of the total variance; the impact of vicariance (rifting and uplifting) on the phylogeography was considerable. A distribution model of the catfish is proposed which combines the separation by rifting several million years ago with a high gene flow in the western rift due to historical connectivity among lakes and rivers.     

Trematode metacercariae from the cranial cavity of African catfish Clarias gariepinus (Burchell, 1822) from Lake Tana,Ethiopia

Metacercariae of two species of trematodes from the fam. Diplostomidae from the cranial cavity of the African catfish Clarias gariepinus are described. The metacercaria Tylodelphys grandis n. sp. is described for the first time. Data are presented on the infection rate of catfishes in Lake Tana.     

Geographic differentiation of <Emphasis Type="Italic">Cobitis shikokuensis</Emphasis> inferred from mtDNA RFLP analysis

Mitochondrial DNA divergence among populations of the Japanese spinous loach Cobitis shikokuensis, endemic to Shikoku Island, was investigated by restricted fragment length polymorphism analysis. A total of 68 restriction sites on DNA fragments from the cytochrome b to D-loop regions and from the 12S rRNA to 16S rRNA regions, amplified by PCR, were analyzed. A total of 12 haplotypes (plus 6 in outgroups) were detected in 268 specimens collected from 19 localities in seven rivers (and 41 specimens from four localities in three rivers in outgroups). Three of the seven river populations of C. shikokuensis were shown to have unique haplotypes, and four of the seven river populations were monomorphic. The nested structure of the haplotype network for populations of C. shikokuensis exhibited two large clades corresponding to (1) populations from the Shimanto River and its neighbors and (2) two genetically divergent populations in the Shigenobu and Iwamatsu Rivers. The population from the Shimanto River, the largest river inhabited by C. shikokuensis, maintains great haplotype diversity as well as the allozyme diversity previously reported. On the other hand, populations from the Hiji River, the second largest river, which exhibited the highest allozyme diversity, were monomorphic in their mtDNA. The nested clade analysis (NCA) revealed that past fragmentation between the above two clades could occur in the initial distribution process of C. shikokuensis. The large genetic divergence of two river populations from the Shigenobu and Iwamatsu Rivers was inferred to be caused by a process of long distance colonization and fragmentation. MtDNA introgression into the Hiji River population from southern river populations was suggested. Taking genetic divergence into consideration, each river population of C. shikokuensis should be conserved separately as like a distinct species, and conservation programs for the small populations showing less genetic variability should be invoked as soon as possible.     

基于线粒体控制区的嘉陵裸裂尻鱼种群遗传结构分析

嘉陵裸裂尻鱼为青藏高原特有鱼类,近年来随自然地理气候的变迁和人类活动的影响,种群数量急剧减少。为了解嘉陵裸裂尻鱼的遗传背景以便更好的保护其遗传资源,本研究采用线粒体控制区部分序列变异,分析了嘉陵裸裂尻鱼6个地理种群的遗传结构和分布动态。在147尾个体中共发现17个变异位点,定义了14种单倍型,群体总的单倍型多样性较高为0.810,核苷酸多样性低为0.00698。AMOVA分析显示,44.29%的分子差异源于群体间,55.71%的分子差异源于群体内,群体间遗传分化极显著。Fst值统计检验表明,除宕昌群体和舟曲群体之间差异不显著外,其余两两群体之间Fst值统计检验均显著。基因流估计显示各群体间的基因流水平较高,遗传交流较频繁。Mantel test检验表明,嘉陵裸裂尻鱼种群之间遗传分化程度与地理距离存在显著相关。系统树和单倍型网络进化图显示,6个地理群体的单倍型按照嘉陵江水系和渭河水系形成两个大的类群。错配分布和中性检验表明嘉陵裸裂尻鱼群体在近期历史上群体大小保持稳定,未出现显著的种群扩张。根据本文所揭示的嘉陵裸裂尻鱼种群遗传结构特征,建议将分布在嘉陵江水系的嘉陵裸裂尻鱼作为一个整体进行保护,嘉陵裸裂尻鱼渭河种群属高度分化的单倍型类群,且遗传多样性极低,需对该种群进行优先保护。     

An analysis of genetic variation in Astragalus cremnophylax var. cremnophylax, a critically endangered plant, using AFLP markers

A recently developed molecular technique (amplified fragment length polymorphisms, AFLP) was used for characterizing genetic heterogeneity within and among populations of a critically endangered species of plant, Astragalus cremnophylax var. cremnophylax. Using AFLP, up to 50 polymorphic genetic markers per AFLP-PCR amplification were generated, and a total of 220 variable markers overall. This information was used first to assess genetic diversity within each of the three known populations of Astragalus cremnophylax var. cremnophylax from Grand Canyon National Park in Arizona, USA: North Rim (NR; n= 970), South Rim Site 1 (SR1; n= 500), and South Rim Site 2 (SR2; n= 2). Diversity in the form of average heterozygosity (H) and the proportion of polymorphic genes (P) was greatest in the NR population ((H) = 0.13 and (P) = 0.38) and least in the SR2 population ((H) = 0.02 and (P) = 0.04). Diversity was also quite low for the SR1 population ((H) = 0.04 and (P) = 0.10). In addition, substantial genetic differentiation among populations was indicated by both phenetic (AMOVA) and genetic analyses (overall corrected F_ST= 0.41). This finding was corroborated by the results of several multivariate analyses which utilized the genetic data, including a UPGMA cluster analysis and a principal coordinate analysis which revealed the existence of discrete groups corresponding to the populations. Population structure was further revealed within the NR population which was known to consist of four spatially separated groups of plants. Several recommendations for the future management of the species are discussed.     

Low genetic differentiation among morphologically distinct Labeobarbus species (Teleostei: Cyprinidae) in the Lake Victoria and Albertine basins,Uganda: insights from mitochondrial DNA

Labeobarbus altianalis and L. bynni bynni are hexaploid cyprinid fishes in the genus Labeobarbus. In the Great Lakes region of Africa, these two large-bodied barbs exhibit considerable morphological variations. Their intraspecific classification, currently based on geographical distribution and morphological variation, is of limited application due to the overlapping nature of the water systems. Patterns of genetic variation in the Albertine and Victoria drainage basins in Uganda were assessed using mitochondrial sequences of the control region (470 basepairs) and the cytochrome b gene (627 basepairs). At the control region 36 distinct haplotypes were observed in a total of 177 individuals. Relatively low overall nucleotide diversity (π = 0.010) was observed. Hierarchical analysis of the molecular variance revealed significant differentiation between populations in the total sample (F _ST = 0.172, p < 0.001), among populations within each basin (F _SC = 0.047, p < 0.001), but no significant subdivision among basins (F _CT = 0.131, p > 0.05). Phylogenetic analysis of the control region haplotypes resulted in a star-shaped phylogeny, with no clusters that reflect current taxonomic designation, morphotypes or basins. Phylogenetic analysis of cytochrome b gene sequences resulted in a tree topology similar to that observed for the control region. Thus the morphological characteristics separating the two species are intraspecific variation and the whole sample probably belongs to the same species.     

利用COI基因序列分析长江与澜沧江水系日本沼虾群体的遗传结构

测定了我国长江水系和澜沧江水系的日本沼虾9个群体,共79个个体的线粒体COI基因序列片段(约450bp),结果发现有89个变异位点,共计有46个单倍型。其中云南昆明(KM)群体具有较丰富的遗传多样性(h=1.000,π=0.028),而重庆(CQ)群体的遗传多样性最小(h=0.700,π=0.008)。AMOVA分析表明,群体间的遗传变异占总遗传变异的9.66%,而90.34%的遗传变异源于群体内。采用邻接法(NJ)构建的分子系统树显示,46个单倍型明显地聚为长江中下游和长江上游与澜沧江两个族群。其结果可以为合理开发和利用日本沼虾自然野生资源,以及建立和保护日本沼虾种质资源库及基因库提供必要的参考。     

Mitochondrial phylogeography of a Beringian relict: the endemic freshwater genus of blackfish Dallia (Esociformes)

Mitochondrial genetic variability among populations of the blackfish genus Dallia (Esociformes) across Beringia was examined. Levels of divergence and patterns of geographic distribution of mitochondrial DNA lineages were characterized using phylogenetic inference, median‐joining haplotype networks, Bayesian skyline plots, mismatch analysis and spatial analysis of molecular variance (SAMOVA) to infer genealogical relationships and to assess patterns of phylogeography among extant mitochondrial lineages in populations of species of Dallia. The observed variation includes extensive standing mitochondrial genetic diversity and patterns of distinct spatial segregation corresponding to historical and contemporary barriers with minimal or no mixing of mitochondrial haplotypes between geographic areas. Mitochondrial diversity is highest in the common delta formed by the Yukon and Kuskokwim Rivers where they meet the Bering Sea. Other regions sampled in this study host comparatively low levels of mitochondrial diversity. The observed levels of mitochondrial diversity and the spatial distribution of that diversity are consistent with persistence of mitochondrial lineages in multiple refugia through the last glacial maximum.     

Microsatellite and mitochondrial DNA variation defines island genetic reservoirs for reintroductions of an endangered Australian marsupial, <Emphasis Type="Italic">Perameles bougainville</Emphasis>

Natural populations of the endangered western barred bandicoot (Perameles bougainville) now exist on only two islands in Shark Bay, Western Australia. Our aim was to investigate genetic diversity in natural, reintroduced, and captive populations of the bandicoots and to assess the extent of divergence between the populations. The contemporary isolation of the natural populations has resulted in heterogeneity of allele frequency between the islands, which has acted to maintain a higher combined diversity than would be expected from either population on its own. These findings highlight how remnant island populations can act as genetic reservoirs to maximize diversity for reintroductions into a species former range. Although diversity is high between island populations, diversity within populations, based on six microsatellite loci, are amongst the lowest ever recorded for populations of marsupials. The mtDNA sequence data indicate that the two remaining natural populations show only minor divergence from each other, with the five haplotypes separated by just single base pairs. The reintroduced population and captive colonies show evidence for the loss of diversity related to genetic drift operating on small isolated populations.     

青藏高原濒危植物唐古特大黄的遗传多样性

唐古特大黄(Rheum tanguticum)是中国传统的中藏药材,近几年由于生境的严重破坏,已濒临灭绝,并被列入濒危植物名单。为了探索唐古特大黄物种濒危的原因并保护其野生资源,本研究采集了9个居群87个个体的唐古特大黄样本,基于该物种的叶绿体基因trn S-G序列对其进行了遗传多样性研究。结果表明,唐古特大黄物种具有较高的遗传多样性水平(Ht=0.694),其中95.97%的遗传分化来自于居群间(G_(ST)=0.960),4.03%的遗传分化来自于居群内(Hs=0.028)。AMOVA分析也显示唐古特大黄居群间基因流较小(N_m=0.01),存在较高的遗传分化(F_(ST)=0.9631)。唐古特大黄较高的遗传多样性水平可能与该物种较长的进化史和生活史有关,居群间较高的遗传分化可能与高山地区特殊的地理环境和人类活动有关。根据研究结果,建议对唐古特大黄所有野生居群进行就地保护,同时收集种质资源开展异地繁殖工作,以保护物种的遗传多样性,维持其进化潜力。     

Detection of novel mitochondrial haplotype variants in populations of the Mediterranean fruit fly,Ceratitis capitata,from Tunisia,Israel and Morocco

The direct analysis of DNA sequence‐based mitochondrial haplotypes in individuals from populations of the Mediterranean fruit fly, Ceratitis capitata, from Tunisia, Morocco and Israel has revealed levels of genetic diversity that far exceed those previously described. A total of 33 distinct haplotypes were identified from 117 individuals representing seven populations from these countries. A network of haplotypes was constructed showing that we have captured essentially all of the sequence variations present in these populations for this gene. These results have important implications for future studies of the genetic structure of this and other closely related pest species.     

Plitvice Lakes National park harbors ancient,yet endangered diversity of trout (genus Salmo)

National park Plitvice Lakes is the oldest, the largest and the most visited national park in Croatia, well known for its stunning karstic watersheds that supply Plitvice Lakes and exceptionally valuable biodiversity. Lack of knowledge on the taxonomic status, population structure and viability of trout in the Plitvice Lakes National park, as well as the possibility of existence of cryptic diversity, motivated this study which aimed to determine: taxonomic status and phylogenetic relationship of Plitvice Lakes trout with other Salmo species, genetic structure and diversity of their populations, as well as future viability of populations. 150 samples of trout were obtained from 17 localities. Two mitochondrial gene markers, gene for cytochrome b and mitochondrial control region were used in phylogenetic reconstruction, as well as in population genetic investigation. Intraspecific and intrapopulation genetic diversity was described by calculating several measures of genetic polymorphism, while gene flow among populations was estimated as the migration rates and as the number of immigrants per generation. Phylogenetic trees revealed that Plitvice Lakes watershed is inhabited by two evolutionary independent units of the genus Salmo, representing two species, Salmo labrax Pallas, 1814 and Salmo trutta Linnaeus, 1758. Possibly ‘pure’ populations of both species were found alongside several admixed ones in which both species are present. Our data has shown low intraspecific and intrapopulational diversities for Plitvice Lakes trout and restricted gene flow. Small effective sizes of populations and weak interconnections between them, which are most likely a consequence of fragmentation and habitat degradation, accentuating the need for urgent conservation measures.     

Effects of silvicultural practices on genetic diversity and population structure of white spruce in Saskatchewan

Forest harvesting and renewal practices using clearcut harvesting followed by artificial and natural regeneration (NR) may impact genetic diversity in subsequent forest tree populations. Plantations (PL) and phenotypic selections may exhibit lower genetic diversity than natural old growth (OG) and naturally-regenerated young populations because they may have a narrow genetic base. We used ten (six EST and four genomic) microsatellite loci, to reassess genetic impacts of silvicultural practices in white spruce (Picea glauca), previously assessed by using 51 RAPD markers by Rajora (1999). Allelic diversity at the genomic microsatellite loci was about three times higher than at the EST-derived microsatellite loci. Although the trends for microsatellite genetic diversity among different stands types were similar to that observed for RAPD markers, with natural OG stands showing the highest and tree improvement selections the lowest allelic and genotypic genetic diversity, no significant differences were observed for microsatellite genetic diversity among OG, young NR, PL and open-pollinated progeny of first-generation phenotypic selections (SEL). The inbreeding levels and genetic differentiation among populations within OG, NR and PL were also similar. However, phenotypic selections had somewhat different genetic constitution as they showed the highest genetic distances with OG, NR and SEL. On the other hand, the lowest genetic distances were observed between the OG and NR stands, which also had similar levels of genetic diversity. Our study suggests no significant negative impacts of harvesting and alternative reforestation practices on microsatellite genetic diversity in white spruce and calls for using more than one marker type in assessing the genetic impacts of silvicultural practices in forest trees.     

Molecular relationships within Bostrychia tenuissima (Rhodomelaceae, Rhodophyta)

Bostrychia tenuissima King and Puttock is restricted to southern Australia and New Zealand. Previous studies in Australia have revealed two distinct patterns in the presence of osmotically active polyols. Southern populations only have D-sorbitol whereas northern populations have both D-sorbitol and D-dulcitol. These polyol patterns lead to speculation on the ecotypic differentiation of these two population types. Using single-stranded confirmation polymorphism to rapidly score plastid haplotypes, plus DNA sequencing, a 100% congruence was found between polyol patterns and plastid haplotype. Analysis of 33 B. tenuissima isolates shows that the plastid relationships closely follow biogeo-graphic regions, with south-eastern Australia (southern NSW and Victoria) and South Australia and Tasmania having one haplotype and central and northern NSW having two alternate haplotypes. There is an overlap at the haplotype boundary just south of Sydney, New South Wales.     

Chloroplast DNA study in wild populations and some cultivars of Prunus avium L.

The PCR-RFLP technique was used to detect chloroplast DNA diversity in wild populations of Prunus avium from five European deciduous forests and some cultivars. A study of 10.8% of the total chloroplast genome detected eight insertion-deletion (indel) mutations, distributed over 12 haplotypes. Six haplotypes (H1, H2, H3, H4, H5 and H6) were found in wild populations and eight (H2, H6, H7, H8, H9, H10, H11 and H12) in the cultivars. Only two haplotypes (H2 and H6) are shared by the wild populations and the cultivars. The most-abundant and frequent haplotype in wild populations is H2 (frequency=78%). The wider geographical distribution along with the high frequency reflects its ancient origin. Of the five populations, three are polymorphic. Populations GA (Scotland) and KE (Germany) have unique haplotypes. The total cpDNA diversity in wild populations is h_T=0.40, and a major portion of it is within populations (h_S=0.37). The genetic differentiation among populations was low (G_STC=0.08) and no genetic structure among wild populations was observed. A minimum-length spanning tree, demonstrating relationships among the haplotypes in wild populations, indicated two possible chloroplast lineages. The ten identified cultivars were represented by seven haplotypes; this result proposes the possible utilisation of the PCR-RFLP technique for the characterisation of sweet cherry cultivars. The cpDNA diversity in P. avium should be considered carefully for phylogenetic studies involving this species. Received: 10 July 2000 / Accepted: 19 October 2000     

Genetic variation and geographical structure of five mouse-sized opossums (Marsupialia, Didelphidae) throughout the Guiana Region

Aim and location To study the patterns of genetic variation and geographical structure of five forest‐dwelling didelphid species distributed throughout the Guiana Region (Marmosops parvidens, M. pinheiroi, Monodelphis brevicaudata, Marmosa murina, Micoureus demerarae) and place the results for wide‐ranging species (M. murina, M. demerarae) in the broader geographical context of the rest of the taxon ranges based on published data. Methods Variation in the mitochondrial cytochrome b gene were analysed in order to assess intra‐specific sequence divergence as well as haplotypic and nucleotide diversity among populations. Relationships between haplotypes were inferred by cladistic (maximum parsimony) and probabilistic (maximum likelihood) approaches, allowing comparisons between tree topologies and patterns of populations geographical distribution. Results Phylogenetic analysis of the Guiana Region populations suggest the lack of common patterns of geographical structure among mouse‐sized opossums except for both Marmosops species. Marmosops parvidens and M. pinheiroi showed individuals from Surinam strongly related with those from Guyana, and haplotypes from French Guiana having a basal position. Concerning Micoureus demerarae, haplotypes from Venezuela were positioned as ancestral, in contrast with Monodelphis brevicaudata, whose French Guiana haplotypes were clustered in a basal position. No evidence of geographical structure was observed for Marmosa murina. Genetic variation within Guiana Region populations fluctuated between 1% for M. murina and 7% in the case of M. brevicaudata. Regarding the widely distributed species, phylogeographical structure at the scale of the Amazon Basin suggests that Guiana Region populations are the sister group of south‐eastern Amazonian and Atlantic Forest populations, thus resulting in an eastern clade well separated from the western Amazonian regions. Main conclusions Monophyly of mouse‐sized opossums haplotypes over the Guiana Region confirms the presence of a well‐differentiated zoogeographical area relative to other Amazonia bioregions. Low genetic diversity among Guiana Region samples suggests a relatively recent origin of populations dating from later Miocene and Pleistocene periods. Moreover, nucleotide and haplotypic diversity values suggest an evolutionary scenario of rapid population growth and dispersal over the Guiana territory, from an ancestral population with small effective size. Dispersal events – rather than vicariance – seem to be responsible for the present genetic and phylogeographical patterns observed in the Guiana Region.     

基于叶绿体DNA非编码序列的蒙古扁桃谱系地理学研究

该研究选取中国西北干旱区第三纪孑遗植物蒙古扁桃（Amygdalus mongolica）,基于叶绿体DNA非编码trnH psbA序列对蒙古扁桃17个居群324个个体进行了谱系地理学研究。结果表明：（1）蒙古扁桃trnH psbA序列长度350 bp,变异位点63个,共有9种单倍型,居群间总遗传多样性为（H_t）为0.758,居群内平均遗传多样性为（H_s）为0.203,贺兰山东麓及阴山南麓边缘的居群具有较高的单倍型多样性及核苷酸多样性并固定较多特有单倍型,推测这2个地区是蒙古扁桃在第四纪冰期时的重要避难所。（2）AMOVA分析表明,居群间的遗传变异为83.84%,居群内的遗传变异为16.16%,居群间遗传分化系数N_st>G_st（N_st=0.733, G_st=0.655, P>0.05）,表明蒙古扁桃不存在明显的谱系地理结构;根据单倍型地理分布及网络关系图,把蒙古扁桃自然地理居群分为东、西两大地理组群,而且东、西地理组群没有共享单倍型;居群遗传结构分析表明,两大地理组群遗传分化较大。（3）蒙古扁桃居群在间冰期或冰期后经历了近期的居群扩张,由于奠基者效应使得多数居群只固定了单一的单倍型。