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1.
L. W. Mengistu G. W. Mueller-Warrant R. E. Barker 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(1-2):70-79
The genetic diversity of Poa annua L.populations collected from western Oregon grass-seed fields was surveyed using 18 randomly amplified polymorphic DNA (RAPD) markers. Markers from 1357 individual plants from 47 populations collected at three sampling dates (fall, winter, and
spring) for 16 sites were used to measure genetic diversity within and among populations. Site histories varied from low to
high herbicide selection pressure, and some sites were subdivided by 3 years of differing post-harvest residue management.
Gene diversity statistics, simple frequency of haplotype occurrence, and analysis of molecular variance (AMOVA) revealed the
presence of significant variability in P. annua among sites, among collection dates within sites, and within collection dates. Nei gene-diversity statistics and population-differentiation
parameters indicated that P. annua populations were highly diverse. Mean Nei gene diversity (h) for all 47 populations was 0.241 and total diversity (HT) was 0.245. A greater proportion of this diversity, however, was within (HS=0.209) rather than among (GST=0.146) populations. When populations were grouped by season of collection, within-group diversity was HS=0.241, while among-group diversity was GST=0.017. When populations were grouped by site, within-group diversity was HS=0.224, while among-group diversity was GST=0.087. The diversity among populations within season for fall, winter, and spring collections was GST=0.121, 0.142, and 0.133, respectively. Populations collected from fields with histories of high herbicide selection pressure
showed low differentiation among collection dates, with GST as low as 0.016, whereas those collected from fields with low herbicide selection pressure showed greater differentiation
among collection dates, with GST as high as 0.125. At high selection-pressure sites, populations were also lower in gene diversity (as low as h=0.155), while
at low selection-pressure sites there was higher gene diversity (as high as h=0.286). The site to site variability was greater
for the high selection-pressure sites (GST=0.107 or 69% of the total among-population variance), while the season of germination variability was greater at sites of
low herbicide-selection pressure (GST=0.067, or 70% of the total among-population variance). High initial diversity coupled with a long-term re-supply of genotypes
from the seed bank must have been factors in maintaining the genetic diversity of this weed despite the intensive use of herbicides.
Knowledge of the genetic diversity of Willamette Valley P. annua should help in formulating more effective strategies for managing this weed.
Received: 24 July 1999 / 11 November 1999 相似文献
2.
MYONG GI CHUNG 《Plant Species Biology》1994,9(3):177-182
Abstract Genetic diversity of Korean populations in Hosta clausa was investigated using starch gel electrophoresis. Hosta clausa is widespread, grows only along streamsides, and has both sexual and asexual reproduction. Populations of the species are small and isolated. Thirty-two percent of the loci examined were polymorphic, and mean genetic diversity within populations (Hep=0.082) was lower than mean estimates for species with very similar life history characteristics (0.131), particularly for its congener H. yingeri (0.250). The mean number of multilocus genotypes per population was 8.7, and genotypic diversity index (DG) was 0.84. Significant differences in allele frequencies among populations were found in all seven polymorphic loci (P < 0.001). About one-fifth of the total allozyme variation was among populations (GST=0.192). Indirect estimate of the number of migrants per generation (Nm=0.48, calculated from mean GST) and nine private alleles found indicate that gene movement among populations was low. The low levels of genetic diversity within populations and the relatively high levels of genetic diversity among populations suggest that strong moist habitat preferences, clonal reproduction, low level of gene flow among populations, genetic drift, and historical events may have played roles in the genetic structuring of the species. 相似文献
3.
Genetic diversity of the Chestnut blight fungus Cryphonectria parasitica in four French populations assessed by microsatellite markers 总被引:2,自引:0,他引:2
Microsatellites are powerful markers to infer population genetic parameters. Here, 13 microsatellite loci isolated from a genomic and a cDNA library of Cryphonectria parasitica were used to characterize the genetic diversity and structure of four French populations. Twelve of these loci were polymorphic within populations, and average gene diversity (He) was estimated to be 0.35. There was a lower genetic diversity in a south-eastern population relative to three south-western populations. In these three populations, microsatellite genotypic diversity was higher than vegetative compatibility type diversity. A high genetic differentiation (GST = 0.27) suggested a low gene flow and/or founder effects of French populations which are in agreement with low dispersal of spores and different introductions of this species in southern France. This study demonstrates the significance of these microsatellite loci to assess gene flow and reproductive system in this important pathogen. 相似文献
4.
Bryophytes seem particularly suitable to investigate genetic diversity in relation to habitat disturbance due to their large
employment as bioindicators and to the recent application of molecular markers to moss population studies. Genetic variation
and structure were analysed in seven urban, extraurban and remote populations of Leptodon smithii, an epiphytic moss of Quercus ilex, a phanerogamic species of Mediterranean climax vegetation. A total of 210 individual shoots were DNA extracted and amplified
with internal simple sequence repeat (ISSR) primers, and 54 haplotypes were identified. An uneven distribution of haplotype
number and frequencies was observed among sites, with a higher number of haplotypes and more homogeneous haplotype frequencies
in the extraurban/remote populations. Molecular diversity indices were overall higher in the extraurban sites than in the
urban ones. Multilocus linkage disequilibrium values were in line with the occurrence of sexual/asexual reproduction in the
seven populations. The isolation-by-distance model was not supported by Mantel test among sites; however, within-population
fixation index (FST) highlighted a clear relation between genetic and physic distances among trees, suggesting a limited dispersal range for
L. smithii’s spores. The genetic structure was mainly affected by population size, wood structure and extent, and genetic drift consequent
to habitat fragmentation and human-induced disturbance. 相似文献
5.
Liang HH Cheng Z Yang XL Li S Ding ZQ Zhou TS Zhang WJ Chen JK 《Journal of microbiology (Seoul, Korea)》2008,46(5):549-556
Cordyceps sinensis is one of the most valuable medicinal caterpillar fungi native to China. However, its productivity is extremely limited and
the species is becoming endangered. The genetic diversity of eighteen C. sinensis populations across its major distributing regions in China was evaluated by inter-simple sequence repeat (ISSR) markers.
A total of 141 markers were produced in 180 individuals from the 18 populations, of which 99.3% were polymorphic. The low
average of Shannon (0.104) and Nei index (0.07) of the 18 populations indicates that there are little genetic variations within
populations. For all 18 populations, estimates of total gene diversity (HT), gene diversity within populations (HS), coefficient of genetic differentiation (GST), and gene flow (Nm) were 0.170, 0.071, 0.583, and 0.357, respectively. This pattern suggests that the genetic diversity
of C. sinensis is low and most of the ISSR variations are found among populations with little gene exchange. The 18 populations are divided
into five groups based on the genetic distance and the grouping pattern matches with the geographic distribution along the
latitudinal gradient. The five groups show obvious difference in the GST and Nm values. Therefore, the genetic diversification of C. sinensis populations may be determined by geographic isolation and the combined effects of life history characters and the interaction
with host insect species. The information illustrated by this study is useful for selecting in situ conservation sites of C. sinensis. 相似文献
6.
The genetic structure of ten natural populations of Arabidopsis thaliana (L.) Heynh. at eight isozyme loci was studied. The populations were located in the northern part of the species range, 200 km from the north to the south along the Onega Lake coast in Karelia. Considerable genetic diversity (P
99% = 43.7, H
obs = 0.003) was revealed that is not typical of populations of self-pollinating plant species. A direct correlation between the proportion of polymorphic loci and geographical latitude was shown (r = 0.68; P < 0.05). It is suggested that a high polymorphism level in Karelian Arabidopsis thaliana (L.) populations increasing from the south to the north is due to extreme environmental conditions in the northern part of the species range. The distribution of genetic diversity within and between populations is typical of self-pollinating species: the larger part of the total diversity resides among populations (G
ST = 0.583). 相似文献
7.
Alnus hirsuta in Korea was measured to estimate the amount and pattern of genetic diversity and population structure. The mean genetic
diversity within populations was 0.166. Korean alder populations have slightly high levels of genetic diversity compared to
those of two Canadian alder species. The genetic differentiation among populations accounted for 9% of the total variation.
The rate of gene flow was estimated high (Nm=2.63). Analysis of inbreeding coefficient, calculated for all polymorphic loci in each population, showed a substantial heterozygote
deficiency relative to Hardy-Weinberg expectations. The mean G
ST
value of A. hirsuta in Korea was 0.087. The low value of G
ST
in this species, reflecting little spatial genetic differentiation, may indicate extensive gene flow. A relationship between
the mean heterozygosity and annual rainfall showed a positive relationship (r
2=0.54, F=4.67).
Received 8 August 1998/ Accepted in revised form 7 July 1999 相似文献
8.
Abdennacer Boulila Afef Béjaoui Chokri Messaoud Mohamed Boussaid 《Biochemical genetics》2010,48(1-2):57-70
Random amplified polymorphic DNA markers were used to assess the genetic diversity within and among seven Tunisian diploid and polyploid populations of Teucrium polium L. from five bioclimatic areas. Out of the 141 bands generated from eight selected primers, 124 were polymorphic. The genetic diversity within a population (Shannon’s index) was high and varied according both the ploidal levels and bioclimatic zones. The genetic differentiation among populations assessed by G ST and ΦST statistics was high, suggesting a low level of gene flow among them. The major proportion of the variation was attributable to individual differences within populations. The UPGMA analysis based on Nei and Li’s coefficient showed that individuals from each population clustered together. In a dendrogram using the ΦST distance matrix, population grouping is concordant with bioclimates and cytotypes. Conservation strategies should take into account the level of the genetic diversity of the populations according to their bioclimate and ploidal levels. 相似文献
9.
Sonneratia paracaseolaris, is a critically endangered mangrove species in China. Using inter-simple sequence repeats (ISSR) markers, we compared the genetic variation of introduced populations with that of natural populations to check whether the genetic diversity has been conserved. At the species level, genetic diversity was relatively high (P = 81.37%, He = 0.2241, and SI = 0.3501). Genetic variation in introduced populations (P = 75.78%, He = 0.2291, and SI = 0.3500) was more than that in natural populations (P = 70.81%, He = 0.1903, and SI = 0.2980). Based on Nei's GST value, more genetic differentiation among natural populations was detected (GST = 0.3591). Our data show that the genetic diversity of S. paracaseolaris was conserved in introduced populations to some extent, however, owing to the small natural populations and the threats they encountered, more plants should be planted to enlarge and restore the populations. 相似文献
10.
Yan-Fei Liu Ming Xing Wei Zhao Rong-Jun Fan Su Luo Xia Chen 《Plant Systematics and Evolution》2012,298(5):921-930
Rhododendron aureum Georgi (Ericaceae) is a perennial alpine shrub endemic to Changbai Mountain in China. We used ISSR and RAPD markers to describe
the diversity and genetic structure within and among four natural populations located at different altitudes. DNA from 66
individuals was amplified with ten ISSR markers and seven RAPD markers. High genetic diversity was observed by these two techniques
at the species level. The genetic diversity of populations increased with altitudinal gradients from low to high. The coefficient
of gene differentiation (GST 0.3652 in ISSR and 0.2511 in RAPD) and AMOVA analysis revealed that most genetic diversity was distributed within populations
(61.96% in ISSR and 70.23% in RAPD). The estimate of gene flow based on GST was 0.8690 in ISSR and 1.4910 in RAPD. The UPGMA clustering results using ISSR and RAPD showed that all individuals from
the same altitude were gathered together, and the two populations (TYD2a and YHLa) from middle altitudes always clustered
together. Compared with populations from different altitudes, similar genetic diversity and low genetic differentiation were
obtained from populations at the same altitudes, as revealed by ISSR markers. In addition to the reproductive strategy of
R. aureum, these data highlight that local environmental conditions may play an important role in shaping the diversity and genetic
structure of this species. 相似文献
11.
The genetic variation within and among eight Tunisian natural populations of Lavandula multifida L., from different bioclimatic zones was assessed using random amplified polymorphic DNA (RAPDs). Of a total of 97 generated bands from seven selected primers, 84 bands were polymorphic. The genetic diversity within a population was high and varied according to the populations (0.308 < H’ < 0.459) without relationships to altitudes or pluviothermic indices of sites. The genetic differentiation among populations was high (GST = 0.395 and ΦST = 0.318). All population pairs were significantly differentiated. Among populations, within ecological groups genetic structure was high (0.219); whilst among them it was low (ΦCT = 0.049; P < 0.05). The correlation between ΦST and geographic distance matrices among pairs of populations was not significant, suggesting that genetic connectivity between populations has a stochastic component at all spatial scales. The neighbour‐joining cluster analysis showed that individuals from each population clustered together. UPGMA cluster analysis showed that population groupings are not strictly in accordance with bioclimates or geographic location. The genetic differentiation in L. multifida could have occurred at local scales because of genetic drift. Efforts should be made to protect all populations. The maintenance of substantial population size should be initiated via fencing and controlling collection to restore the regeneration of populations. 相似文献
12.
Xiao-Li Peng Chang-Ming Zhao Gui-Li Wu Jian-Quan Liu 《Trees - Structure and Function》2007,21(4):457-464
Repeated cycles of retreat and recolonization during the Quaternary ice ages are thought to have greatly influenced current
species distributions and their genetic diversity. It remains unclear how this climatic oscillation has affected the distribution
of genetic diversity between populations of wind-pollinated conifers in the Qinghai-Tibetan region. In this study, we investigated
the within-species genetic diversity and phylogenetic relationships of Picea likiangensis, a dominant forest species in this region using polymorphic DNA (RAPD) markers. Our results suggest that this species has
high overall genetic diversity, with 85.42% of loci being polymorphic and an average expected heterozygosity (H
E) of 0.239. However, there were relatively low levels of polymorphism at population levels and the differences between populations
were not significant, with percentages of polymorphic bands (PPB) ranging from 46.88 to 69.76%, Nei’s gene diversity (H
E) from 0.179 to 0.289 and Shannon’s indices (Hpop) from 0.267 to 0.421. In accordance with our proposed hypothesis, a high level of genetic differentiation among populations
was detected based on Nei’s genetic diversity (G
ST = 0.256) and AMOVA analysis (Phi
st = 0.236). Gene flow between populations was found to be limited (Nm = 1.4532) and far lower than reported for other conifer species with wide distribution ranges from other regions. No clusters
corresponding to three morphological varieties found in the south, north and west, respectively, were detected in either UPGMA
or PCO analyses. Our results suggest that this species may have had different refugia during the glacial stages in the southern
region and that the northern variety may have multiple origins from these different refugia. 相似文献
13.
Genetic diversity and population differentiation of chestnut blight fungus, Cryphonectria parasitica, in China as revealed by RAPD 总被引:1,自引:0,他引:1
Seventeen Cryphonectria parasitica populations sampled from six regions in China were investigated using RAPD. Across all 169 isolates from the 17 populations
evaluated, 52 of the 71 markers (73%) were polymorphic, total genetic diversity (h) was 0.1463, and Shannon’s index was 0.2312. Diversity within populations accounted for 74% of total genetic diversity, and
genetic differentiation among populations was 0.26 (G
ST = 0.26). Gene flow was 1.4 among the populations; higher gene flow was found among populations within regions and among regions
[N
m (G
SR) = 2.8 and N
m (G
RT) = 3.5]. The unweighted pair group mean analysis (UPGMA) dendrogram revealed two distinct clusters: the northern China group
and the southern China group. The spatial autocorrelation analysis revealed that the variation at most loci was randomly distributed
and lacked spatial structure, but several loci and closer distances were spatially structured. Human activity and habitat
could also be important factors affecting genetic structure among C. parasitica populations in China. Genetic diversity was highest in Southwest China, descending in an orderly fashion to Northeast China.
This pattern indicated that Southwest China might be the center of origin of C. parasitica in China. The present study provides useful information for understanding the origin and spread of chestnut blight fungus
in China and valuable data for formulating relevant strategies for controlling the disease in China. 相似文献
14.
Abstract Junipers are main components of semiarid forests in Central Asia. Conservation of these plant genetic resources should be based on an understanding of factors that have shaped species‐level genetic variation. We used Juniperus seravschanica Kom. as a model species to investigate patterns and processes that may be associated with these factors. Novel plastid DNA markers (two minisatellites, one transversion, one indel) were identified and applied to investigate haplotype diversity and population structure in Kyrgyzstan. In total, 540 individuals from 15 populations were analyzed and 11 haplotypes detected. Strong divergence between populations from northern and southern Kyrgyzstan was evident from the haplotype distribution. Gene diversity within populations ranged from 0.083 to 0.765, and was on average higher in southern (0.687) than in northern populations (0.540). A similar pattern was detected in allelic richness. Analysis of molecular variance (AMOVA) revealed that 11.9% of the total genetic variation was due to differences among regions, 1.5% among populations, and 86.6% within populations. NST was not significantly different from GST (0.125), suggesting no evidence of a phylogeographic pattern. A Mantel test detected a weak but significant isolation‐by‐distance pattern for the whole dataset and southern populations separately. These results suggest that the north of Kyrgyzstan was relatively recently colonized by migrants from southern populations, probably associated with favorable conditions during the early Holocene. The humid Fergana Valley and Fergana Range are probable ecological barriers to gene flow between northern and southern populations. 相似文献
15.
Dysosma pleiantha, an important threatened medicinal plant species, is restricted in distribution to southeastern China. The species is capable
of reproducing both sexually and asexually. In this study, inter-simple sequence repeat marker data were obtained and analyzed
with respect to genetic variation and genetic structure. The extent of clonality, together with the clonal and sexual reproductive
strategies, varied among sites, and the populations under harsh ecological conditions tended to have large clones with relatively
low clonal diversity caused by vegetative reproduction. The ramets sharing the same genotype show a clumped distribution.
Across all populations surveyed, average within-population diversity was remarkably low (e.g., 0.111 for Nei’s gene diversity),
with populations from the nature reserves maintaining relatively high amounts of genetic diversity. Among all populations,
high genetic differentiation (AMOVA: ΦST = 0.500; Nei’s genetic diversity: G
ST = 0.465, Bayesian analysis: ΦB = 0.436) was detected, together with an isolation-by-distance pattern. Low seedling recruitment due to inbreeding, restricted
gene flow, and genetic drift are proposed as determinant factors responsible for the low genetic diversity and high genetic
differentiation observed. 相似文献
16.
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
17.
We investigated the extent of genetic differentiation among populations of fujihatazao,Arabis serrata along an altitudinal gradient at Mt. Fuji in Shizuoka Prefecture. This species is a perennial plant, widely distributed in
Japan forming small isolated populations. However, at Mt. Fuji, this species constitutes a large population distributed from
1440 to 2400 m altitude. A total of 411 individuals were sampled from ten subpopulations. Eighteen loci were detected on eleven
enzyme systems. Eleven loci were monomorphic and seven loci were polymorphic with a mean of 2.11 alleles per loci. Nei's genetic
distance (mean 0.01) and genetic identity (mean 0.968) were very similar among populations indicating a low genetic differentiation.
The total genetic diversity (H
T
) estimated for the polymorphic loci was, in average, 0.396. The mean gene differentiation (GST=0.091) was very low. Gene frequency of seven polymorphic loci was analyzed by spatial autocorrelation methods based on Moran's
indexes. Only Pgi-3 exhibited a significant negative autocorrelation (−0.160;P<0.05); other loci values ranged from −0.134 to 0.027. Gene flow estimated by indirect methods varied between genes but most
of the values were high (meanNm=20.8) suggesting that subpopulations at different altitudes are probably connected. Despite plants at different altitudes
present different ecological traits (e.g., differences in phenology, growth and reproductive traits), subpopulations ofA. serrata are still low differentiated, at least for the loci studied. This may be explained by the recent origin of some habitats
(e.g., second crater and surrounded areas) in this locality. 相似文献
18.
Jia‐Jia Fan Xiao‐Ping Zhang Kang Liu Hui‐Jun Liu Li Zhang Xiao‐Ping Wang Xiao‐Hong Li 《Nordic Journal of Botany》2019,37(2)
Pteroceltis tatarinowii (Cannabaceae), a relic tree endemic to China, is mainly distributed in limestone mountains and has a wide geographical range. In this study, 12 microsatellite primer pairs were assayed to analyse the genetic pattern and gene flow among 461 individuals sampled from 23 wild populations of P. tatarinowii. A high level of genetic diversity was detected based on high values of total alleles (159), the number of alleles (NA = 6.373), expected heterozygosity (HE = 0.696) and observed heterozygosity (HO = 0.679). The high genetic diversity in this species may be attributed to its long‐life history, wide geographical distribution and wind dispersal. Only low genetic differentiation (GST = 0.137, FST = 0.138) was found among populations. Gene flow (migrants per generation, Nm) was estimated to be 1.56. This moderate level of gene flow possibly decrease interpopulation differentiation by buffering against genetic drift and improving gene exchange. However, spatial genetic structure was detected throughou the sampled range of the species (r = 0.311, p < 0.05) as well as in southern China (r = 0.453, p < 0.05), and may be related to terrain heterogeneity and the demographic history of P. tatarinowii. The east‐west high mountains of southern China might serve as physical barriers to seed and pollen flow. The isolation and local adaptation of different refugia may further limit gene flow. In addition, geographically remote populations might fail to effectively disperse pollen and seeds. Based on the above‐mentioned results, some suggestions for the conservation of the species are presented. 相似文献
19.
Toadflaxes (Linaria Miller) represent the largest genus of the tribe Antirrhineae (formerly included in the Scrophulariaceae) of the Plantaginaceae
family. These taxa vary according to their ranges (narrow-regional–widespread), biological traits (duration, flower morphology,
breeding system) and ecological preferences. No comparative genetic studies have been performed up to the moment and the levels
and distribution of genetic diversity within this genus remain undocumented. We have conducted an allozyme study in 8 taxa
of Section Supinae. Five of them are narrow endemic, self-incompatible, insect-pollinated outcrossers that inhabit relatively unaltered habitats.
The other three taxa are widespread, small-flowered selfers that inhabit crops subjected to high levels of recurrent disturbance.
Linaria taxa showed moderate to high levels of genetic diversity. Parameters of genetic diversity were directly addressed to differences
in breeding systems. Mean number of alleles per locus, total genetic diversity and genetic diversity within populations were
higher among the outcrossers than among the selfers, (A
e = 2.28 vs. 1.23; H
T = 0.24 vs. 0.13; H
S = 93.99% vs. 54.2%) while genetic diversity among populations and population differentiation were lower for the outcrossers
than for the selfers (D
ST = 0.02% vs. 45.98%; G
ST = 0.03 vs. 0.52). Gene flow within and among populations produced a higher number of different genotypes (mean N
G = 16 for outcrossers vs. 5.4 for selfers) and migrants (mean N
m = 4.58 for outcrossers vs. 0.84 for selfers) that were attributed to an effective pollinator service in outcrossing populations.
Differences in the levels and distribution of the genetic diversity are discussed in relation to biological and autoecological
constraints of each group of taxa. 相似文献
20.
Genetic variation and structure of six natural populations of Lepidium draba L. from Eastern Anatolia were assessed using random amplified polymorphic DNA (RAPD) markers. For RAPD analysis, 12 primers generated 218 reproducible bands across the six populations analyzed, of which 73 bands (33.3%) were polymorphic. The mean Nei’s gene diversity value for all six populations was 0.1771. Shannon’s information index varied with population (0.2278–0.3082), averaging 0.2608. Analysis of molecular variance (AMOVA) showed that genetic diversity was greater within populations (58.66%) than among populations (30.68%). In addition, the variation between groups was 10.33%. The genetic differentiation among populations (G ST) was 0.3210, indicating that most genetic diversity occurs within populations. Gene flow (Nm) was low, at only 0.5288. 相似文献