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1.
Ceratopteris thalictroides (L.) Brongn is a tetraploid fern species that contains at least three cryptic species, the south, the north and the third
type. In this study we combined data from both chloroplast DNA (cpDNA) and nuclear DNA sequences of three diploid species
and three cryptic species of C. thalictroides to unravel the origin of the cryptic species, particularly of the reticulate relationships among the diploid and tetraploid
taxa in the genus Ceratopteris. Of the three diploid species examined, C. cornuta had cpDNA identical to that of the tetraploid third type plants, and this diploid species is a possible maternal ancestor
of the tetraploid third type. Analysis of the homologue of the Arabidopsis thaliana LEAFY gene (CLFY1) identified ten alleles in the genus Ceratopteris, with six alleles found in C. thalictroides. The unrooted tree of the CLFY1 gene revealed four clusters. Each cryptic species showed fixed heterozygosity at the CLFY1 locus and had two alleles from different clusters of the CLFY1 tree. Consideration of the cpDNA sequences, CLFY1 genotypes of the cryptic species and CLFY1 gene tree in concert suggested that the cryptic species of C. thalictroides had originated through independent allopolyploidization events involving C. cornuta and two unknown hypothetical diploid species. 相似文献
2.
Dai-Chang Kuo Chia-Chia Lin Kuo-Chieh Ho Yu-Pin Cheng Shih-Ying Hwang Tsan-Piao Lin 《Conservation Genetics》2010,11(3):803-812
Cinnamomum kanehirae Hayata (Lauraceae), the most valuable subtropical and temperate broadleaf timber tree in Taiwan, is rapidly disappearing
from the wild. Taking advantage of a scion garden established by the Taiwan Forestry Research Institute, we examined patterns
of chloroplast DNA (cpDNA) variations in 19 populations including 94 individuals. By sequencing two cpDNA fragments using
universal primers (the trnL-trnF and petG-trnP intergenic spacers), we found eight polymorphic sites, six haplotypes, and extremely low nucleotide diversity (π = 0.00016) from 792 bp aligned sequences. The ancestral haplotype is widely distributed. Among the populations studied, three
separated populations, at Yungfeng, Fuli, and Tahu have high nucleotide diversity. No phylogeographical structures of haplotypes
were revealed because the tests of N
ST−G
ST for populations did not differ from zero in any situations; a ‘star-like’ genealogy is characteristic when all haplotypes
rapidly coalesce and is a general outcome of population expansion. The neutrality test also suggested demographic expansion.
The genetic divergence and diversity analyses suggested that two potential refugia existed during the last glaciation with
a major one located in southeastern Taiwan and a minor one located in Tahu in north-central Taiwan in the Hsuehshan Range,
west of the Central Mountain Range. 相似文献
3.
Saussurea involucrata (Asteraceae) is a medicinal and second-degree national priority endangered plant that is mainly distributed in the high latitude region of the western Tianshan Mountains. The population is fragmented and isolated, and extensive human impact merits a suitable and specific conservation strategy, which can be compiled based on the genetic diversity, population structure, and demographic history. Phylogeographic studies were conducted on a total of five natural populations and 150 individuals were sampled. Data from three cpDNA intergenic spacer regions (trnL-F, matK, and ndhF-rpl32) and nrDNA ITS sequences showed that twelve haplotypes in cpDNA and five haplotypes in nrDNA indicated high genetic diversity among populations sampled (H T?=?0.820 and 0.756) and within populations sampled (H S?=?0.792 and 0.721). Additionally, the high genetic diversity did not mirror genetic structure in either cpDNA (F ST?=?0.03153, G ST?>?N ST, p?<?0.05) or nrDNA (F ST?=?0.03666, meaningless G ST and N ST). Two groups (north and south) were determined for a SAMOVA analysis. Based on this analysis, the demographic history was conducted with a Bayesian Skyline Plot and Isolation with Migration analysis, which showed sustainable and stable extension without a marked bottleneck. Divergence time was indicated at c. 6.25 Mya (90%HPD: 15.30–0.22 Mya) in the Miocene, which is consistent with the formation of the Kelasu section of Tianshan. The southern populations in the Bayanbulak and Gonglu regions require additional attention and transplanting would be an effective way to restore rare cpDNA haplotypes, increase effective population size, and migration rate. Our results suggested that in situ conservation of S. involucrata in western Tianshan should be the main strategy for protection and recovery of the species. 相似文献
4.
This paper illustrates the phylogeographical structure of Saxifraga callosa in order to describe its genetic richness in refugial areas and to reconstruct its glacial history. S. callosa is a species spread throughout south-east France and Italy with a high distribution in the Maritime Alps. Four chloroplast
microsatellite and AFLP markers were analyzed in populations of S. callosa. The size variants of all tested loci amount to 11 different haplotypes. Intrapopulational haplotype variation was found
in two of the populations analyzed: on the Mt. Toraggio in the Maritime Alps, and in the Apuan Alps. On the other hand, no
intrapopulational variation was found in 25 populations, most of which were sampled from isolated areas. Analysis of the haplotype
distribution showed that population subdivision across all populations was high (G
ST = 0.899). Moreover, its genetic structure was studied using AMOVA and STRUCTURE analysis. The study legitimated inferred
conclusions about the phylogeographical structure of the species and identified centers of diversity. Considerations concerning
genetic structure and divergence among three major clades (Maritime Alps, Apuan Alps and Apennines), the patchy distribution
of haplotypes, and the high number of private haplotypes support the proposal that S. callosa survived in some refugia within the Italian Peninsula refugium, and that mainly northern populations of refugia were involved
in postglacial recolonization. 相似文献
5.
Commiphora wightii is a medicinally important endangered species endemic to the Thar Desert of Rajasthan, India and adjoining areas of Pakistan.
The populations of this species are declining sharply because of its extensive use as a natural herb. Random amplified polymorphic
DNA analysis was conducted to find the genetic variation among 7 populations of C. wightii. Of the 100 random primers screened, 44 primers yielded 220 loci. Statistical analysis indicated low genetic diversity (H
pop = 0.0958; I = 0.1498; mean polymorphic loci = 14.28%), and high genetic differentiation among the populations (G
ST = 0.3990; AMOVA Φ
ST of 0.3390; Bayesian θ
(II) = 0.3002). The low genetic diversity may be due to geographic isolation and restricted gene flow (N
m = 0.7533) between the fragmented populations. Unsustainable utilization of the plant has fragmented the population continuum
which served the purpose of genetic exchange between populations. Mantel’s test was performed which revealed a highly significant
positive correlation between genetic and geographic distance (r
2 = 0.614, P = 0.023) among the populations studied. Low variation can also be attributed to poor seed setting and the slow growth pattern
of the species, which is also an apomict. In UPGMA dendrogram the Commiphora wightii samples were divided into two major and one minor cluster. These findings can serve as a guide to preserving the genetic
resources of this medicinal plant species. 相似文献
6.
Climate changes during glacial periods have had significant effects on the current distribution of plant species. Palaeontologial
data suggest that modern cycads originated in southwest China. Cycas debaoensis (Cycadaceae) is an endangered species restricted to a small area of southwest China. This species has been classified into
two types: sand and karst, according to the soil matrix they grow on. To determine the locations of its glacial refugia and
its genetic structure, we examined chloroplast sequence variation of the atpB-rbcL and psbA-trnH intergenic spacers. Four chloroplast DNA haplotypes were obtained from 120 individuals collected from 11 populations covering
the entire extant distribution range of the species. Significant population subdivision was detected (G
ST = 0.684 and F
ST = 0.74160), suggesting low levels of gene flow between regions and populations. There was marked haplotype differentiation
between populations in the sand and karst regions, with only one haplotype being present in both. The molecular phylogenetic
data, together with the geographic distribution of the haplotypes, suggest that C. debaoensis experienced range contraction during glacial periods, and that the current populations are still confined to the areas of
the original refugia. These results implied that isolated refugia might have maintained in both sand and karst regions during
the last glacial maximum and even earlier glaciations. The low within-population diversity of C. debaoensis suggested that there were strong bottleneck events or founder effects within each separate region during the Quaternary climatic
oscillations. These findings are important for the conservation of this endangered species. 相似文献
7.
Oxytropis chankaensis Jurtz. (Fabaceae) is an endangered perennial tetraploid species endemic to the Khanka Lake coast. In Russia, O. chankaensis is distributed across a very restricted zone along the western shore of this lake. To characterise all known populations
of this species, we assessed the genetic diversity of four noncoding regions of chloroplast DNA (cpDNA). Variable sites detected
within the trnL–trnF, the petG–trnP, and the trnS–trnG regions allowed the identification of seven haplotypes. On the other hand, no variation was found in the trnH–psbA region. O. chankaensis exhibited an overall low level of nucleotide diversity (π = 0.00052) but a marked haplotype diversity (h = 0.718). A combination of three or four haplotypes was found in each population, and most of the cpDNA variation (above
90%) was distributed within populations. The level of genetic structure that we detected in O. chankaensis using maternal plastid DNA markers was much lower (G
ST = 0.037) than the average that is estimated for angiosperms. We found no evidence for isolation by distance or for phylogeographic
structuring in O. chankaensis. Our data suggest that autopolyploidy has arisen more than once in the evolutionary history of this species. Repetitive expansion
and contraction during past and ongoing demographic events both seem to be involved in shaping the current genetic structure
of O. chankaensis. This study provides valuable information for developing the most appropriate strategy for conserving this endemic species
with a narrow habitat range. 相似文献
8.
Two chloroplast intergenic spacers (trnD-trnT and rps16-trnK) were used to study the phylogeographical structure of Helianthemum
songaricum in northwestern China, with 12 haplotypes detected. Phylogenetic analysis showed that H. songaricum comprised two lineages, one distributed in the Yili Valley and the other in the western Ordos Plateau. Nested clade phylogeographic
analysis likewise indicated that haplotypes in the Yili Valley and those in the western Ordos Plateau formed sister monophyletic
clades. This lineage split was also supported by AMOVA analysis and the Mantel test. AMOVA showed that 99.41% of variance
in H. songaricum occurred between the two distribution regions, and correlation between genetic differentiation and geographical distances
was significant (r
2 = 0.877, P < 0.0001). All populations in the Yili Valley shared haplotype A with high frequency, and range expansion was detected by
nested clade analysis and strongly supported by negative Fu’s F
S-values, Tajima’s D-values, and mismatch distribution analysis. We speculate that aggravation of the dry and cold climate during the early Quaternary,
combined with plant physiological features, were determining factors contributing to the lineage split, and climate oscillations
most likely led to the Yili range expansion. The high drift load (F
ST = 0.9923, G
ST = 0.663) and inbreeding load (H
S = 0.219) of H. songaricum indicate a significant extinction risk, and protective measures should be taken immediately. 相似文献
9.
Berchemiella wilsonii var. pubipetiolata (Rhamnaceae) is an endangered tree in eastern China. Habitat destruction has resulted in fragmentation of remnant populations
and extinction of local populations. AFLP and cpDNA markers were used to determine the population structure of remnant populations
of B. wilsonii var. pubipetiolata. Moderate nuclear genomic diversity was found within each of the four remnant populations (H
S = 0.141–0.172), while the cpDNA haplotype diversity in each population ranged from 0.356 to 0.681. Six haplotypes were identified
by a combined cpRFLP and cpSSR analysis in a total of 89 individuals. AMOVA revealed significantly AFLP genetic differentiation
within and between regions (ΦSC = 0.196, ΦCT = 0.396, respectively), and a high cpDNA haplotype differentiation between regions (ΦCT = 0.849). The results suggest low gene flow between populations of B. wilsonii var. pubipetiolata. Strong genetic divergence between two regional populations as revealed by both AFLP and cpDNA markers provided convincing
evidence that two distinct evolutionary lineages existed, and should be recognized as ‘evolutionary significant units’ (ESUs)
for conservation concerns. 相似文献
10.
Fujii N 《Journal of plant research》2007,120(4):491-500
Phylogeographic analyses using chloroplast DNA (cpDNA) variation were performed for Pedicularis ser. Gloriosae (Orobanchaceae). Eighty-one plants of 18 populations of 6 species (P. gloriosa, P. iwatensis, P. nipponica, P. ochiaiana, P. sceptrum-carolinum and P. grandiflora) were analyzed. Fifteen distinct haplotypes were identified based on six cpDNA regions: the intergenic spacer between the
trnT and trnL 3′exon, trnL 3′exon-trnF, atpB-rbcL, accD–psaI, the rpl16 intron and the trnK region (including the matK gene). Via phylogenetic analyses of the haplotypes, two continental species, P. sceptrum-carolinum and P. grandiflora, were placed at the most ancestral position in the trees. The former species is widely distributed in the Eurasian continent,
and the latter is distributed in Far East Asia. Two robust major cpDNA clades (clades I and II) were revealed in the Japanese
archipelago, although the statistical values of monophyly of these clades were weak. Clade I included the haplotypes (A-1,
A-2, B-1, B-2 and J) of three species (P. gloriosa, P. iwatensis and P. ochiaiana), and Clade II included seven haplotypes (C-D, E-1, E-2 and F-H) of P. nipponica. These results suggest that this series originated on the Eurasian continent and that subsequently populations at the eastern
edge of the continent differentiated into the two Japanese lineages.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
In this study, the mtDNA COI genes of 124 individuals in Brachionus calyciflorus complex were sequenced and analyzed. Overall, 84 mtDNA haplotypes were defined, and were split into three clades by the phylogenetic
trees. The divergences of COI gene sequence among the three clades ranged from 11.4 to 22.5%, indicating the occurrence of
three cryptic species (cryptic species 1, cryptic species 2, and cryptic species 3). Within cryptic species 3, a remarkable
degree of differentiation (F
st = 0.0947) might be attributable to habitat fragmentation, restricted gene flow, and founder effect, most probably together
with local adaptation. The more shared haplotypes were observed, and a non-significant correlation existed between geographic
and genetic distance, suggesting that some ancestral haplotypes might be involved in a past range expansion, and as founders
give a similar distribution pattern among geographic populations. The networks were also in agreement with the pattern of
genetic differentiation in B. calyciflorus species complex revealed by molecular phylogeny. The nested clade analysis suggested a slight geographic structure in the
network I, network II, and the highest nesting clade levels within the network III. Under the possible effect of the Younger
Dryas Event, the three cryptic species might have survived in multiple relict refugia throughout the south of China. The co-occurrence
of cryptic species 2 and 3 might be found in Guangzhou and Hainan due to the possible interference of the barrier and contiguous
range expansion. After the Younger Dryas Event, cryptic species 3 with high colonization ability might have arrived and colonized
whole habitats at first, and reduce effective gene flow among cryptic species, thus effectively increasing persistence of
founder events. Cryptic species 2 might, respectively, have expanded their ranges into Wuhu and Nanjing regions only because
of the probable barrier of the Yangtze River, its weak colonization abilities and the ‘priority effects’ of cryptic species
3. Cryptic species 1 distributed exclusively in Danzhou probably failed to expand its ranges into mainland China because of
small population size, weaker dispersal capacity, and the barrier of the Qiongzhou Strait. 相似文献
12.
Yong Liu Ronglei Liu Liangchen Ye Jun Liang Fujun Xuan Qianghua Xu 《Hydrobiologia》2009,618(1):125-137
Portunus trituberculatus is a commercially important species widely spread in the East China Sea. Intraspecific variation of the mitochondrial DNA
cytochrome oxidase subunit I (mtDNA COI) gene was investigated in 213 individuals from six localities (Changjiang Estuary,
Shengsi Islands, Zhoushan Islands, Dongtou Islands, Dinghai Bay, and Quanzhou Bay) ranging from north (31°21′N) to south (24°55′N)
coastal waters of the East China Sea. Overall, a total of 27 mtDNA haplotypes and 21 variable sites were detected in the 787 bp
segment of COI gene. Analysis of mtDNA COI sequence data revealed that crabs from the six localities were characterized by
moderately high haplotypic diversity (h = 0.787 ± 0.026), while sequence divergence values between haplotypes were relatively low (π = 0.00241 ± 0.00098). Each population
was characterized by a single most frequent haplotype, shared among all six localities, and a small number of rare ones, typically
present in only one or two individuals and representative of a specific population. However, neither the neighbor-joining
tree nor the minimum spanning network (MSN) based on the haplotype data exhibited geographical patterns of the six populations.
Mismatch distribution analysis of P. trituberculatus individuals sampled from the six localities suggested that sudden population expansion might have occurred in CJ and SS population
that might be consistent with over-exploitation of the swimming crab. Analysis of molecular variance (AMOVA) and F
ST statistics showed that significant genetic differentiation existed among the SS, ZS, DT, DH, and QZ populations, suggesting
that gene flow might be reduced, even between the geographically close sites, despite the high potential of dispersal. The
possible causes of the observed genetic heterogeneity among the P. trituberculatus populations and the potential applications of the mtDNA COI marker in the artificial breeding and fisheries management are
discussed.
Handling editor: C. Sturmbauer 相似文献
13.
Qiang Fan Sufang Chen Renchao Zhou Xu Xiang Wenbo Liao Suhua Shi 《Conservation Genetics》2011,12(3):753-760
Understanding the amount and distribution of genetic diversity in natural populations can inform the conservation strategy
for the species in question. In this study, genetic variation at eight nuclear microsatellite loci was used to investigate
genetic diversity and population structure of wild litchi (Litchi chinensis Sonn. subsp. chinensis). Totally 215 individuals were sampled, representing nine populations of wild litchi. All eight loci were polymorphic, with
a total of 51 alleles. The expected heterozygosity in the nine populations ranged from 0.367 to 0.638 with an average value
of 0.526. Inbreeding within wild litchi populations was indicated by a strong heterozygote defect. Significant bottleneck
events were detected in the populations from Yunnan and Vietnam, which could be responsible for lower levels of genetic diversity
in these populations. Measures of genetic differentiation (F
ST = 0.269) indicated strong differentiation among wild litchi populations. Significant correlation was found between genetic
differentiation and geographical distance (r = 0.655, P = 0.002), indicating a strong isolation by distance in these populations. Bayesian clustering suggested genetic separation
among three regional groups, namely, the western group, the central group and the eastern group. Some conservation strategies
for wild litchi populations were also proposed based on our results. 相似文献
14.
Pacific halibut collected in the Aleutian Islands, Bering Sea and Gulf of Alaska were used to test the hypothesis of genetic
panmixia for this species in Alaskan marine waters. Nine microsatellite loci and sequence data from the mitochondrial (mtDNA)
control region were analyzed. Eighteen unique mtDNA haplotypes were found with no evidence of geographic population structure.
Using nine microsatellite loci, significant heterogeneity was detected between Aleutian Island Pacific halibut and fish from
the other two regions (F
ST range = 0.007–0.008). Significant F
ST values represent the first genetic evidence of divergent groups of halibut in the central and western Aleutian Archipelago.
No significant genetic differences were found between Pacific halibut in the Gulf of Alaska and the Bering Sea leading to
questions about factors contributing to separation of Aleutian halibut. Previous studies have reported Aleutian oceanographic
conditions at deep inter-island passes leading to ecological discontinuity and unique community structure east and west of
Aleutian passes. Aleutian Pacific halibut genetic structure may result from oceanographic transport mechanisms acting as partial
barriers to gene flow with fish from other Alaskan waters. 相似文献
15.
The analysis of 135 mitochondrial D-loop sequences of the Iberian autochthonous red-legged partridge (Alectoris rufa) from wild population hunting bags from various locations and fowl runs in Spain yielded 37 different haplotypes. Among these,
three haplotypes correspond to chukar partridges (Alectoris chukar), indicating genetic introgression from birds illegally introduced for restocking: three individuals carrying such haplotypes
where found in natural populations, one appeared among those sampled on a mass reproduction farm and the remaining 10 in another
fowl-run. The geographical origin of the contaminating chukar haplotypes could be assigned to the most easterly area of the
chukar partridge geographical distribution in China. Molecular diversity parameters in the A. rufa samples indicate a considerable amount of genetic variation. ΦST showed significant differences among populations that are not explained by geographical distance alone. Particularly, one
northern population (Palencia) shows a certain degree of genetic differentiation that could reflect a previously suggested
subspecies division.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
16.
In Japanese Stegnogramma pozoi subsp. mollissima (Fisher ex Kunze) K. Iwats. there is the intrasubspecific variation among rbcL sequences. Northern and southern plants are genetically differentiated for maternally inherited cpDNA. In the present study
we examined allozyme polymorphisms to test the hypothesis that northern and southern plants may be separate species. Based
on allozyme data, the degree of gene flow among populations was estimated to be large. The artificial crossing experiments
between cpDNA haplotypes also suggested that isolation has not developed among these cpDNA haplotypes. However, interpopulation
genetic differentiation in cpDNA was observed even in the small area at the foot of Mt. Hakone, and the cpDNA haplotypes appear
to have different habitat preferences.
Received: May 1, 2001 / Accepted: September 30, 2001 相似文献
17.
Koowadjanakul N Jindamorakot S Yongmanitchai W Limtong S 《Antonie van Leeuwenhoek》2011,100(2):207-217
Five strains (LN12, LN14T, LN15T, LN16 and LN17T) representing three novel methylotrophic yeast species were isolated from the external surface of plant leaves by three-consecutive
enrichments. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, the sequence analysis
of the D1/D2 domain of the large subunit (LSU) rRNA gene and the phylogenetic analysis, the five strains were assigned to
be one novel Ogataea species and two novel Candida species. Three strains (LN12, LN14T and LN16) represent a single novel species of the genus Ogataea, for which the name Ogataea phyllophila sp. nov. is proposed. The type strain is LN14T (= BCC 42666T = NBRC 107780T = CBS 12095T). Strain LN15T was assigned to be Candida chumphonensis sp. nov. (type strain LN15T = BCC 42667T = NBRC 107781T = CBS 12096T). Strain LN17T represented another novel species of Candida that was named Candida mattranensis sp. nov. (type strain LN17T = BCC 42668T = NBRC 107782T = CBS 12097T). 相似文献
18.
Previous studies have reached different discussions about the genetic variation and genetic structure of Quercus crispula populations in northeastern Japan. This is a common oak species in Eastern Asia. Some studies have suggested that the populations
in northeastern Japan were derived from those remaining in the southwest after the last glacial maximum (LGM), whilst other
studies have found evidence that populations persisted in northeastern Japan during the LGM. Using seven highly polymorphic
nuclear simple sequence repeat loci, we investigated the genetic structure of 16 Q. crispula populations along a latitudinal gradient in northeastern Japan (northern Honshu and Hokkaido), spanning about half of the
species’ biogeographic range in the country. Although the level of population differentiation was low (F
ST = 0.021;
G¢\textST G^{\prime}_{\text{ST}} = 0.090), two geographically differentiated clusters were detected by STRUCTURE analysis. The first cluster included most
of the populations in Hokkaido, and may indicate continued survival throughout past glacial periods. We found a significant
decrease in allelic richness with latitude, so the second cluster may represent an expansion of the lineage from Honshu during
the post-glacial period. These results should enhance our understanding of historical north–south migrations of this species
in northeastern Japan. 相似文献
19.
Sal (Shorea robusta Gaertn., Dipterocarpaceae) is a wind-pollinated tropical tree species found in southern Asia. We investigated the genetic
diversity and structure at four microsatellites of 15 populations comprising continuous-peripheral and disjunct-peripheral
populations in Nepal. Estimates of genetic diversity (N
A = 8.98, H
O = 0.62, H
E = 0.69) were similar when compared with those of other tropical tree species. A higher level of genetic diversity was observed
in continuous-peripheral populations (N
A = 9.61, H
O = 0.67, H
E = 0.72) as compared to disjunct-peripheral (N
A = 8.04, H
O = 0.55, H
E = 0.64). Population differentiation was higher among disjunct-peripheral populations (F
ST = 0.043) than among continuous peripherals (F
ST = 0.012). There was a significant association between gene flow distances and genetic differentiation (r
2 = 0.128, P ≤ 0.007). No spatial arrangement of populations according to their geographical locations was found. Based on observed genetic
diversity protection of some populations in continuous-peripheral range are suggested for the sustainable conservation of
genetic resources of the species while protection of some disjunct-peripheral populations are also recommended for conserving
rare alleles. 相似文献
20.
The Puerto Rican crested toad (Peltophryne lemur) is currently composed of a single wild population on the south coast of Puerto Rico and two captive populations founded
by animals from the northern and southern coasts. The main factors contributing to its decline are habitat loss, inundation
of breeding ponds during storms, and impacts of invasive species. Recovery efforts have been extensive, involving captive
breeding and reintroductions, habitat restoration, construction of breeding ponds, and public education. To guide future conservation
efforts, genetic variation and differentiation were assessed for the two captive colonies and the remaining wild population
using the mitochondrial control region and six novel microsatellite loci. Only two moderately divergent mitochondrial haplotypes
were found, with one fixed in each of the southern and northern lineages. Moderate genetic variation exists for microsatellite
loci in all three groups. The captive southern population has not diverged substantially from the wild population at microsatellite
loci (F
ST = 0.03), whereas there is little allelic overlap between the northern and southern lineages at five of six loci (F
ST > 0.3). Despite this differentiation, they are no more divergent than many populations of other amphibian species. As the
northern breeding colony may not remain viable due to its small size and inbred nature, it is recommended that a third breeding
colony be established in which northern and southern individuals are combined. This will preserve any northern adaptive traits
that may exist, and provide animals for release in the event that the pure northern lineage becomes extirpated. 相似文献