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1.
Aim To examine the phylogeographic pattern of a volant mammal at the continental scale. The pallid bat (Antrozous pallidus) was chosen because it ranges across a zone of well‐studied biotic assemblages, namely the warm deserts of North America. Location The western half of North America, with sites in Mexico, the United States, and Canada. Methods PCR amplification and sequencing of the mitochondrial control region was performed on 194 pallid bats from 36 localities. Additional sequences at the cytochrome‐b locus were generated for representatives of each control‐region haplotype. modeltest was used to determine the best set of parameters to describe each data set, which were incorporated into analyses using paup *. Statistical parsimony and measurements of population differentiation (amova , FST) were also used to examine patterns of genetic diversity in pallid bats. Results We detected three major lineages in the mitochondrial DNA of pallid bats collected across the species range. These three major clades have completely non‐overlapping geographic ranges. Only 6 of 80 control‐region haplotypes were found at more than a single locality, and sequences at the more conserved cytochrome‐b locus revealed 37 haplotypes. Statistical parsimony generated three unlinked networks that correspond exactly to clades defined by the distance‐based analysis. On average there was c. 2% divergence for the combined mitochondrial sequences within each of the three major clades and c. 7% divergence between each pair of clades. Molecular clocks date divergence between the major clades at more than one million years, on average, using the faster rates, and at more than three million years using more conservative rates of evolution. Main conclusions Divergent haplotypic lineages with allopatric distributions suggest that the pallid bat has responded to evolutionary pressures in a manner consistent with other taxa of the American southwest. These results extend the conclusions of earlier studies that found the genetic structuring of populations of some bat species to show that a widespread volant species may comprise a set of geographically replacing monophyletic lineages. Haplotypes were usually restricted to single localities, and the clade showing geographic affinities to the Sonoran Desert contained greater diversity than did clades to the east and west. While faster molecular clocks would allow for glacial cycles of the Pleistocene as plausible agents of diversification of pallid bats, evidence from co‐distributed taxa suggests support for older events being responsible for the initial divergence among clades. 相似文献
2.
Climatic oscillations during the Quaternary strongly affected the distribution of warm-temperate tree species, which experienced
local restrictions into ice-free areas and posterior expansions. To evaluate the impact of these range movements on the genetic
structure of populations, we performed a phylogeographical analysis of the species Nothofagus obliqua with chloroplast DNA markers. A total of 27 populations covering the whole natural distribution range were analyzed using
polymerase chain reaction-restriction fragment length polymorphism. Diversity (h
T, h
S), allelic richness (r
g), and differentiation among populations for unordered (G
ST) and ordered alleles (N
ST) were calculated. The relationships among haplotypes were evaluated by the construction of a minimum spanning network. The
spatial distribution of the genetic variation was analyzed through a Mantel test and with a nested analysis of molecular variance
to differentiate between geographic regions. The screening of 11 non-coding regions allowed the identification of 14 haplotypes.
A high genetic differentiation was detected (N
ST = 0.875 and G
ST = 0.824) with the existence of phylogeographic structure (p < 0.05). The distribution of the genetic variation was partially explained by the topography of the region when the populations
were divided longitudinally into Coastal Mountains, Central Valley, and Andes Mountains (ϕ
RT = 0.093, p = 0.001). In agreement with pollen records, our results support the hypothesis of Coastal refuges since the region harbors
high diversity together with older and private haplotypes. Long-lasting persistence of some Coastal populations without contribution
to re-colonization is proposed. Additional refuges are also postulated along the Andes and Longitudinal Valley. Survival in
multiple glacial refuges is discussed together with the possible migratory routes. 相似文献
3.
We assessed genetic variation in a total of 22 populations of the tree species Cordia africana Lam. in Ethiopia and analyzed the country-wide impact of population history, forest disturbance and alteration of land use
on extant intraspecific diversity. Amplified Fragment Length Polymorphisms (AFLPs) and chloroplast microsatellite markers
were investigated. The analyses of the AFLP data revealed high diversity in all investigated populations: the percentage of
polymorphic loci (PPL) ranged from 62.2% to 92.2% and Nei's gene diversity from 0.220 to 0.320 within the populations. The
mean PPL and the mean diversity within populations were 85.7% and 0.287, respectively. The analysis of molecular variance
revealed a moderate level of differentiation (ΦST = 0.07, p < 0.001) among the populations. The Mantel test proved a significant but low correlation (r = 0.31, p < 0.001) between the geographic distance and the genetic differentiation matrices. Only three different cpDNA haplotypes
were observed; no more than two haplotypes were found in any population. The dominant haplotype with an overall frequency
of 81% was observed in all populations. The level of differentiation among the populations was comparatively low at chloroplast
DNA (G
ST = 0.18, R
ST, N
ST = 0.22). The observed patterns and levels of genetic variation within and among the populations indicate that efficient gene
flow via pollen and seed is likely to be the main factor contributing to the maintenance of genetic diversity in natural and
disturbed conditions. 相似文献
4.
Yongshuang Xiao Yan Zhang Tianxiang Gao Takashi Yanagimoto Mamoru Yabe Yasunori Sakurai 《Environmental Biology of Fishes》2009,85(4):303-314
The genetic diversity and population genetic structure of the small yellow croaker (Larimichthys polyactis) were investigated. One hundred and fourteen individuals were sampled from 8 localities of the Yellow Sea and the northern
East China Sea. Genetic variation in DNA sequences were examined from the first hypervariable region (HVR-1) of the mitochondrial
DNA control region. High levels of haplotype diversity (h = 0.98 ± 0.87%) in the HVR-1 region were detected, indicating a high level of genetic diverstiy. A total of 84 polymorphic
sites were found, and 87 haplotypes were defined. The pairwise nucleotide differences between samples ranged from 3.83 ± 2.19
to 6.56 ± 3.25. The demographic history of L. polyactis was examined by using neutrality tests and mismatch distribution analysis, which indicated a Pleistocene population expansion
at about 49,300–197,000 years. The star burst structure of the minimum spanning tree also suggestted a very recent origin
for most haplotypes. Hierarchical molecular variance analysis (AMOVA) and conventional population Fst comparisons revealed no significant genetic structure throughout the examined range, which is inconsistent with previous findings based on the morphological and ecological studies. Long-term dispersal and high
gene flow likely have contributed to the genetically homogeneous population structure of the species. The knowledge on genetic
diversity and genetic structure will be crucial to establish appropriate fishery management stocks for the species. 相似文献
5.
Jinliang Zhao Yang Cao Sifa Li Jiale Li Yanfei Deng Guoqing Lu 《Environmental Biology of Fishes》2011,90(1):85-93
Ample studies have been conducted to investigate the population genetic structure of grass carp Ctenopharyngodon idella in the Yangtze River, China. However, samples from the upper reaches were not included. In this study, we collected samples
from the entire river, including three locations in the upper reaches: Yibin, Banan and Yunyang, two locations in the middle
reaches: Shishou and Ruichang and one location in the lower reaches: Hanjiang, and sequenced three mitochondrial coding genes
(ND5, ND6 and Cytb) and one control region (i.e., the D-loop). Nineteen haplotypes were observed in grass carp of the Yangtze River through
the analysis of combined sequence data sets (around 4428 bp). Haplotype diversity indices (0.6000 ∼ 0.9333) and nucleotide
diversity indices (0.0002 ∼ 0.0020) demonstrated low genetic diversity in the Yangtze grass carp. The analysis of molecular
variance and the fixation index (F
ST = 0.0202) revealed insignificant genetic difference between samples from different reaches. Two monophyletic lineages of
haplotypes were identified, with the lineage A experiencing potential expansion events. Along with previous findings, this
study provides a better understanding of genetic diversity and variation of grass carp in the Yangtze River and will be served
as an important baseline to evaluate the long-term impact of the Three Gorges Dam and other hydroelectric facilities on fish
biodiversity. 相似文献
6.
Katsutoshi Watanabe Nian-Hong Jang-Liaw Chun-Guang Zhang Sang-Rin Jeon Mutsumi Nishida 《Ichthyological Research》2007,54(3):253-261
A phylogeographic analysis of two bagrid catfishes in Taiwan was conducted using sequence data from a portion of the mitochondrial
DNA (mtDNA) control region. For Pseudobagrus brevianalis, which is most probably endemic to Taiwan, a total of eight haplotypes were detected in 189 specimens from nine river systems
covering its entire distribution range, from northern to central western areas of the island. Obvious genetic differentiation
was observed among its populations (average F
ST = 0.753); in particular, the northernmost Tamsui River population was fixed for a single endemic haplotype. Nested clade
phylogeographic analysis (NCPA) indicated that the dispersal center of mtDNA was the area around the Touchien River and Holong
River, north to the Miaoli Plateau, in northwestern Taiwan, suggesting both northward and southward dispersal in this species.
There was no evidence for the validity of P. taiwanensis, the nominal species described from Taiwan, morphologically similar to P. brevianalis. We confirmed that P. adiposalis was distributed discontinuously in three river systems; analysis of 42 specimens from the rivers indicated a total of four
haplotypes and population differentiation (average F
ST = 0.876). Fixation into a largely differentiated haplotype in the northernmost Tamsui River population was also found in
this species, but different processes for this phylogeographic pattern were implied for the two species. Comparison with P. ussuriensis, a widespread continental species morphologically similar to P. adiposalis, suggested the possibility that P. adiposalis is a group of local populations of P. ussuriensis in Taiwan. Two migration routes vs. random fixation scenarios for the population structure of P. adiposalis are discussed with information on other fishes and the geological history of the island. 相似文献
7.
Daniela G. Félix-López Nataly Bolaño-Martinez Pindaro Díaz-Jaimes Erick C. Oñate-González Jorge S. Ramírez-Pérez Emiliano García-Rodríguez David Corro-Espinosa Jesus E. Osuna-Soto Nancy C. Saavedra-Sotelo 《Journal of fish biology》2019,94(4):671-679
We assessed the spatial pattern of genetic structure of smooth hammerhead shark Sphyrna zygaena in 10 localities from the Northern Mexican Pacific. A total of 35 haplotypes were identified in 129 sequences of the mtDNA control region. The results showed slight but significant genetic structure among localities (ΦST = 0.044, P < 0.001). In addition, the localities with highest number of juveniles were genetically different (ΦST = 0.058, P < 0.024), which may be representative of nursery areas. The genetic differentiation pattern can be associated to female philopatry and preference for particular birthing sites. Finally, historical demography shows that S. zygaena populations present a recent demographic expansion that occurred during glacial events in the late Pleistocene to early Holocene. 相似文献
8.
Elongate loach (Leptobotia elongata (Bleeker)), an endemic fish species to China, is a famous ornamental freshwater fish. Here, a comparative study of mtDNA
control region (D-loop) (835 bp) sequences was performed to analyze its wild population structure and evaluate the genetic
diversity for 110 individuals from five locations in the upper reaches of the Yangtze River, China. A total of 49 polymorphic
sites and 45 haplotypes yielded high haplotype diversity (h = 0.952), but low nucleotide diversity (π = 0.00454) as that of many fish species. Sequence divergences between haplotypes ranged from 0.0033 ± 0.0011 to 0.0050 ± 0.0012
in intra-groups, and from 0.0037 ± 0.0.0011 to 0.0050 ± 0.0012 between groups. Significant values of Tajima’s D (−1.86383, P < 0.01) and Fu’s F
S (−25.93, P < 0.01), together with uni-modal mismatch distribution, indicated a recent genetic bottleneck or population expansion of
the species. Analysis of molecular variance (AMOVA) indicated a small amount of differentiation among groups (1.7%); most
of the total variation occurred within groups (98.3%). Also, there was no significant population structure (F
ST = 0.017, P > 0.05), and estimates of gene flows among groups were extremely high (Nm = 28.88), suggesting low genetic divergence between populations in the species. The lack of genetic differentiation among
groups is most likely due to the combined gene flow from the downstream movement of eggs and larvae with currents and the
upstream or downstream migration of adults throughout the distribution. These groups of L. elongata distributed in upper reaches of the Yangtze River should be considered as a single management unit. 相似文献
9.
The Streaked Horned Lark (STHL; Eremophila alpestris strigata) is a federal candidate for listing under the Endangered Species Act. We evaluated the conservation status and level of genetic
diversity of the STHL using the complete mitochondrial ND2 gene. We sampled 32 STHLs from the southern Puget Sound region,
the Pacific coast, and Whites Island in the Columbia River of Washington, and additional 68 horned larks from Alaska, alpine
and eastern Washington, Oregon, California, and Asia (outgroups). Our Maximum Likelihood analysis of 32 haplotypes identified
three geographically concordant clades in Pacific coast states: Pacific Northwest (alpine and eastern Washington, Alaska),
Pacific Coast (western Washington, California), and Great Basin (eastern Oregon). Each of the three clades was supported by
bootstrap values ≥86%. The distance among them varied from 0.72 to 0.79% nucleotide divergence excluding intraclade variation.
The relationship among the clades was not resolved. AMOVA also showed significant structuring of haplotypes among the three
clades. Differences among clades accounted for 75.7% of sequence variation, differences among localities within clades accounted
for 12.1%, and differences among individuals within localities accounted for the remaining 12.2%. Although STHL populations
were closely related to the Californian sample, they appeared unique and isolated. All pairwise F
st values involving the STHL samples were significant (except between themselves). STHLs appear to have remarkably low genetic
diversity; all 32 STHLs shared the same haplotype. Even with small sample sizes, all other localities had multiple haplotypes.
Because the STHL appears to be unique and isolated, and to have little genetic diversity our data suggest it should be a conservation
priority. 相似文献
10.
Fengjuan Zhao Fuli Liu Jidong Liu Put O. AngJr. Delin Duan 《Journal of applied phycology》2008,20(2):191-198
Sargassum muticum is important in maintaining the structure and function of littoral ecosystems, and is used in aquaculture and alginate production,
however, little is known about its population genetic attributes. In this study, random amplified polymorphic DNA (RAPD) and
inter-simple sequence repeat (ISSR) markers were used to investigate the genetic structure of four populations of S. muticum and one outgroup of S. fusiforme (Harv.) Setchell from Shandong peninsula of China. The selected 24 RAPD primers and 19 ISSR primers amplified 164 loci and
122 loci, respectively. Estimates of genetic diversity with different indicators (P%, percentage of polymorphic loci; H, the expected heterozygosity; I, Shannon’s information index) revealed low or moderate level of genetic variations within each S. muticum population, and a high level of genetic differentiations were determined with pairwise unbiased genetic distance (D) and fixation index (F
ST
) among the populations. The Mantel test showed that two types of matrices of D and F
ST
were highly correlated whether from RAPD (r = 0.9706, P = 0.009) or ISSR data (r = 0.9161, P = 0.009). Analysis of molecular
variance (AMOVA) was conducted to apportion the variations among and within the S. muticum populations. It indicated that variations among populations were higher than those within populations, being 55.82% verse
44.18% by RAPD and 55.21% verse 44.79% by ISSR, respectively. Furthermore, the Mantel test suggested that genetic differentiations
among populations were related to the geographical distances (r > 0.6), namely, conformed to the IBD (isolation by distance)
model, as expected from UPGMA (unweighted pair group method with arithmetic averages) cluster analysis. On the whole, the
high genetic structuring among the four S. muticum populations along the distant locations was clearly indicated in RAPD and ISSR analyses (r > 0.9, P < 0.05) in our study. 相似文献
11.
Mitochondrial DNA (mtDNA) control region sequences and microsatellite loci length polymorphisms were used to investigate genetic
differentiation in spotted dolphins (Stenella attenuata) in the Eastern Tropical Pacific and to examine the intraspecific structure of the coastal subspecies (Stenella attenuata graffmani). One-hundred and thirty-five animals from several coastal areas and 90 offshore animals were sequenced for 455 bp of the
mitochondrial control region, resulting in 112 mtDNA haplotypes. Phylogenetic analyses and the existence of shared haplotypes
between the two subspecies suggest recent and/or current gene flow. Analyses using χ2, F
ST (based on haplotype frequencies) and ΦST values (based on frequencies and genetic distances between haplotypes) yielded statistically significant separation (randomized
permutation values P<0.05) among four different coastal populations and between all but one of these and the offshore subspecies (overall F
ST=0.0691). Ninety-one coastal animals from these four geographic populations and 50 offshore animals were genotyped for seven
nuclear microsatellite loci. Analysis using F
ST values (based on allelic frequencies) yielded statistically significant separation between most coastal populations and offshore
animals, although no coastal populations were distinguished. These results argue for the existence of some genetic isolation
between offshore and inshore populations and among some inshore populations, suggesting that these should be treated as separate
units for management purposes. 相似文献
12.
In this study, thirty-six individuals of Acheilognathus macropterus were collected from the Heilongjiang River, the Yangtze River, and the Nandujiang River. Partial mitochondrial cytochrome
b gene region (636 base pair) was sequenced to these samples and 22 haplotypes were found. With A. chankaensis and A. tokinensis as outgroups, their relationships were analyzed. The p-distances were calculated with Mega software and a molecular phylogenetic tree was constructed using the neighbor-joining
(NJ) method. The proportions of main morphological characters were compared as well. P-distances showed that the genetic differences in A. macropterus samples were far smaller than those between these samples and the outgroups. The molecular phylogenetic tree shows that samples
with barbels and those without barbels were intermingled. There was no distinctive difference in proportions of morphological
characteristics among them. These results suggested that samples with barbels and those without barbels (formally identified
as A. taenianalis) are the same species; A. taenianalis is synonymous with A. macropterus. The thirtysix individuals were grouped into five clades and the positions of the samples in the clades were correspondingly
grouped within their geographical distributions. Among the five clades, clades 1 and 5 included samples from the Heilongjiang
River and Nandujiang River respectively. The samples from the Yangtze River scattered into clades 2, 3, and 4. There were
distinctive genetic differences (>5%) among them. Interestingly, the distributions of the 21 samples in these three clades
were not correlated to their geographical distributions. It is postulated that these genetic differences were due to the bitterlings’
mating choice mechanism, the prozygotic isolation. The genetic differences between the fish from Nandujiang River and those
from the mainland indicated that they were separated early. However, the small genetic differences among the samples and the
positions of the fish from the Heilonjiang River in the molecular phylogenetic tree indicate that fish in Heilongjiang River
might have dispersed from the Yangtze River to that area much later.
__________
Translated from Acta Hydrobiologica Sinica, 2006, 39(2): 134–140 [译自: 水生生物学报] 相似文献
13.
《African Journal of Aquatic Science》2013,38(2):143-153
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. 相似文献
14.
Genetic variation of four populations of Sargassum thunbergii (Mert.) O. Kuntze and one outgroup of S. fusiforme (Harv.) Setchell from Shandong peninsula of China was studied with random amplified polymorphic DNA (RAPD) and inter-simple
sequence repeat (ISSR) markers. A total of 28 RAPD primers and 19 ISSR primers were amplified, showing 174 loci and 125 loci,
respectively. Calculation of genetic diversity with different indicators (P%, percentage of polymorphic loci; H, the expected heterozygosity; I, Shannon’s information index) revealed low or moderate levels of genetic variations within each S. thunbergii population. High genetic differentiations were determined with pairwise Nei’s unbiased genetic distance (D) and fixation index (F
ST
) between the populations. The Mantel test showed that two types of matrices of D and F
ST
were highly correlated, whether from RAPD or ISSR data, r = 0.9310 (P = 0.008) and 0.9313 (P = 0.009) respectively. Analysis of molecular variance (AMOVA) was used to apportion the variations between and within the
S. thunbergii populations. It indicated that the variations among populations were higher than those within populations, being 57.57% versus
42.43% by RAPD and 59.52% versus 40.08% by ISSR, respectively. Furthermore, the Mantel test suggested that the genetic differentiations
between the four populations were related to the geographical distances (r > 0.5), i.e., they conformed to the IBD (isolation by distance) model, as expected from UPGMA (unweighted pair group method
with arithmetic averages) cluster analysis. As a whole, the high genetic structuring between the four S. thunbergii populations along distant locations was clearly indicated in the RAPD and ISSR analyses (r > 0.8) in our study. 相似文献
15.
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
16.
Lan Q Shen M Garcia-Rossi D Chanock S Zheng T Berndt SI Puri V Li G He X Welch R Zahm SH Zhang L Zhang Y Smith M Wang SS Chiu BC Linet M Hayes R Rothman N Yeager M 《Immunogenetics》2007,59(11):839-852
Selection and genetic drift can create genetic differences between populations. Cytokines and chemokines play an important
role in both hematopoietic development and the inflammatory response. We compared the genotype frequencies of 45 SNPs in 30
cytokine and chemokine genes in two healthy Chinese populations and one Caucasian population. Several SNPs in IL4 had substantial genetic differentiation between the Chinese and Caucasian populations (F
ST ~0.40), and displayed a strikingly different haplotype distribution. To further characterize common genetic variation in
worldwide populations at the IL4 locus, we genotyped 9 SNPs at the IL4 gene in the Human Diversity Panel’s (N = 1056) individuals from 52 world geographic regions. We observed low haplotype diversity, yet strikingly different haplotype
frequencies between non-African populations, which may indicate different selective pressures on the IL4 gene in different parts of the world. SNPs in CSF2, IL6, IL10, CTLA4, and CX3CR1 showed moderate genetic differentiation between the Chinese and Caucasian populations (0.15 < F
ST < 0.25). These results suggest that there is substantial genetic diversity in immune genes and exploration of SNP associations
with immune-related diseases that vary in incidence across these two populations may be warranted. 相似文献
17.
Mao-feng Yue Ren-chao Zhou Ye-lin Huang Guo-rong Xin Su-hua Shi Li Feng 《Journal of Plant Biology》2010,53(2):165-171
High levels of genetic variation enable species to adapt to changing environments and provide plant breeders with the raw
materials necessary for artificial selection. In the present study, six AFLP primer pairs were used to assess the genetic
diversity of Desmodium triflorum (L.) DC. from 12 populations in South China. A high percentage of polymorphic loci (P = 76.16%) and high total gene diversity (H
T = 0.310) were found, indicating that the genetic diversity of D. triflorum is high at the species level. Genetic diversity was also relatively high at the population level (P = 55.85%, H
e = 0.230). The coefficient of gene differentiation among populations (G
ST) was 0.255, indicating that while most genetic diversity resided within populations, there was also considerable differentiation
among populations. AMOVA also indicated 24.29% of the total variation to be partitioned among populations (ΦST = 0.243). UPGMA clustering analysis based on genetic distances showed that the 12 populations could be separated into three
subgroups: an eastern, a western, and a central-southern subgroup. However, a Mantel test revealed no significant correlation
(r = 0.286, p = 0.983) between the geographical distances and genetic distances separating these populations; mountain barriers to gene
flow and human disturbance may have confounded these correlations. The present study has provided some fundamental genetic
data that will be of use in the exploitation of D. triflorum. 相似文献
18.
Xi-Ping Yuan Yuan-An Wu Bo Hong Deng-Qiang Wang Shao-Ping Liu Da-Qing Chen 《Environmental Biology of Fishes》2012,93(1):137-142
The hillstream fish, Glyptothorax zanaensis (Wu et al., Oceanol Limnol Sin 12:74–79, 1981) is a freshwater teleost species belonging to the order Siluriformes, endemic to Nu River and Lancang River basin. Because wild stocks of G. zanaensis have declined substantially in recent years, owing to overexploitation, pollution, illegal fishing practices and the development
of hydroelectricity in the Nu River, the populations of G. zanaensis have markedly declined in recent years. We studied the mitochondrial DNA cyt b gene to assess the genetic diversity of G. zanaensis in seven tributaries of the Nu River. Seventy variable sites defined 15 haplotypes in 153 individuals. Haplotype diversity
and nucleotide diversity were 0.542 ± 0.014 and 0.011 ± 0.007, respectively. The Sunzu River site had the highest haplotype
diversity (Hd, 0.893 ± 0.014) and nucleotide diversity ( Pi, 0.010 ± 0.012). Genetic diversity was low in the Dong River,
Fengwei River and Mengtong River. Pairwise F
ST
values ranged from 0.00 to 1.00. Significant F
ST
values were found for Sunzu River sampled sites paired with all other populations and Mengtong river sampled site paired
with the others. Furthermore, the Nanpeng River sampled site was significantly differentiated from the Luoming River, Dong
River and Fengwei River sampled sites. Such knowledge is essential for developing appropriate policies for the rational management
of G. zanaensis. 相似文献
19.
Understanding the population structure and evolutionary history of the eastern Pacific seahorse Hippocampus ingens is critical for the effective management of this threatened species. Life history characteristics of H. ingens (site fidelity and brooding of young) may limit gene flow and lead to population differentiation. A recent study analyzing
conserved fragments of the mitochondrial cyt b and control region found no population structure. We re-assess this conclusion with a phylogeographic analysis of relationships
among 115 individuals of H. ingens over a broader geographic range (San Diego Bay in California, Gulf of California, Central America, Ecuador, and Peru) based
on a more variable 428 base pair fragment of the control region. This expanded analysis affirms low overall nucleotide diversity
relative to other seahorses (θπ = 0.004), and shows evidence of a recent bottleneck and population expansion since the middle Pleistocene. AMOVA analysis
shows moderate overall population structure (ΦST = 0.10, P val = 0.00), and pairwise ΦST estimates indicate structure between the Gulf of California and all Pacific coast localities. Knowledge of population structure
in H. ingens may improve conservation efforts by identifying evolutionarily important management units, and could determine source regions
in the continuing trade of seahorses for traditional Chinese medicine. The level of genetic divergence observed between the
Gulf of California and all other localities sampled may distinguish the Gulf as a separate management unit. Additional phylogeographic
research with more quickly evolving genetic markers and targeted sampling at the mouth of the Gulf of California is warranted
to inform strategies for conservation of this threatened seahorse. 相似文献
20.
Daniela Guicking Brigitte Fiala Frank R. Blattner Ferry Slik Maryati Mohamed Kurt Weising 《Tree Genetics & Genomes》2011,7(3):573-585
Macaranga (Euphorbiaceae) has received much ecological and evolutionary research attention as a genus that includes some of the most
conspicuous pioneer trees of Southeast Asian tropical rainforests and because of its manifold associations with ants, including
about 30 species that are obligate ant-plants (myrmecophytes). We used sequence data from three chloroplast DNA loci (ccmp5,
ccmp6, atpB-rbcL) to assess phylogeographical patterns in species of Macaranga, section Pruinosae, sampled from various regions of Borneo and the Malay Peninsula. Forty-nine chloroplast DNA haplotypes (HT) were identified
among 768 specimens from five species, Macaranga gigantea (N = 329; 23 HT), Macaranga pearsonii (N = 347; 21 HT), Macaranga puberula (N = 24; 4 HT), Macaranga hosei (N = 48; 6 HT), and Macaranga pruinosa (N = 20; 5 HT). Forty-one haplotypes were species-specific, whereas eight haplotypes were shared by two, three, or four species
and occupied internal positions in a parsimony network. Population genetic parameters based on haplotype frequencies proved
to be in a similar range in the non-myrmecophytic M. gigantea and in the ant-associated M. pearsonii, which have overlapping distributions in northern and eastern Borneo. A comparison of G
ST and N
ST values revealed a strong phylogeographic structure in both species, whereas colonization pathways suggested by the network
topology were different. Both species exhibited similar levels of haplotypic diversity and moderate to high levels of population
differentiation. There were no obvious indications for an influence of the symbiotic ant partners on the population structure
of their host plants. 相似文献