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1.
Shao-Qing Tang Xiao-Yun Bin Yun-Tao Peng Jun-Ya Zhou Li Wang Yang Zhong 《Genetic Resources and Crop Evolution》2007,54(5):1053-1061
Genetic variation of wild populations and cultivars of Luohanguo (Siraitia grosvenorii), a plant species endemic to southern China, was assessed using random amplified polymorphic DNA (RAPD) and amplified fragment
length polymorphism (AFLP) markers. Based on the results for 130 individuals from seven populations, a high level of genetic
diversity of Luohanguo was observed at the species level. The percentage of polymorphic loci (P) was 89.4%, Nei’s gene diversity (H
e) was 0.239, and Shannon’s information index (H
o) was 0.373 based on the combined AFLP and RAPD data. There was a high degree of genetic differentiation, with 45.1% of the
genetic variation attributed to differences between the populations. The genetic diversity of the Luohanguo cultivars is much
lower than that of wild populations (P = 41.8%, H
e = 0.141, H
o = 0.211), and a distinct genetic differentiation is observed between the cultivars and wild accessions. The pool of genetic
variation in the wild populations provides an excellent gene resource for Luohanguo breeding. 相似文献
2.
Tina Wöhrmann Daniela Guicking Korous Khoshbakht Kurt Weising 《Genetic Resources and Crop Evolution》2011,58(8):1157-1167
A population genetic analysis based on eight genomic SSR markers and three EST-SSR (expressed sequence tags) markers developed
in peach (Prunus persica (L.) Batsch) and Japanese plum (Prunus salicina Lindl.) was carried out in 12 wild populations of cherry plum (Prunus divaricata Ledeb.) sampled along the Iranian coast of the Caspian Sea. A total of 184 alleles (3–31 per locus) were detected with a
mean value of 16.7 alleles per locus. None of the loci or populations showed deviation from Hardy–Weinberg equilibrium, and
all markers proved to be unlinked. The mean values for the observed and the expected heterozygosity were 0.66 and 0.73, respectively.
There was very little genetic differentiation among populations, as was indicated by low overall values of Wright’s FST (0.03) and Nei’s GST (0.08). An analysis of molecular variance (AMOVA) showed that 96.8% of the total variance was attributable to differences
between individuals within populations. Genetic and geographic distances were nevertheless positively correlated, as evidenced
by a Mantel test. The high level of genetic diversity and the apparent lack of genetic structure in wild P. divaricata may be attributed to frequent long distance gene flow through frugivorous birds and possibly humans, as has been documented
for other Prunus species. 相似文献
3.
Emeterio Payró de la Cruz Paul Gepts Patricia Colunga GarciaMarín Daniel Zizumbo Villareal 《Genetic Resources and Crop Evolution》2005,52(5):589-599
The diversity, genetic structure, and genetic flow of wild populations of Phaseolus vulgaris L. within its Mesoamerican area
of domestication, were analyzed by means of morphological and inter-simple sequence repeat molecular markers. Overall, 89%
of the loci studied were polymorphic, 35% in the least diverse population and 65% in the most diverse. Genetic diversity in
the populations was high, between h = 0.14 and 0.29, as was the maximum distance between populations (D = 0.3). Between 40%
and 45% of the diversity was explained by the differences among populations, indicating that a large number of populations
is necessary to represent the wild gene pool in the germplasm collections. We found uniformity in allele frequencies among
the populations, suggesting presence of outcrossing. We did not find correlation between genetic and geographic distances,
but the dendrogram topology suggests geographical isolation due to the mountainous topography. Negative correlations were
observed between the coefficient of variation of seed size and the distance between wild populations and fields . We obtained
a highly negative correlation between percentage of polymorphic loci and distance to the nearest crop field, which also suggests
gene flow from the domesticated populations. These observations suggest that genetic flow is taking place from domesticated
toward wild populations and that the farmer, through his agricultural activities, could be influencing the magnitude and the
characteristics of the gene flow, and along with this, the differentiation of wild populations. New approaches should be established
for conservation in situ and maintaining bio-safety, given the risk of introducing genotypes from the Andes and transgenic
varieties and causing genetic assimilation. 相似文献
4.
Xiao-Qin Sun Yan-Qiu Qu Mi-Mi Li Xiao-Ling Song Yue-Yu Hang 《Genetic Resources and Crop Evolution》2018,65(6):1581-1590
The wild Brassica juncea (L.) Czern. et Coss., systematically belonging to the genus Brassica L. in the Cruciferae family, has become a noxious weed for cropping systems nowadays. Here, simple sequence repeat (SSR) markers were applied to investigate the genetic diversity, genetic structure and migration routes of the wild B. juncea populations in China. The results showed that a total of 90 alleles, with extensive allelic diversity, were observed at the 11 SSR loci of the wild B. juncea. The STRUCTURE analysis indicated that all the 25 wild populations were best described as belonging to two lineages. High Fst value (0.568), together with the partitioning, provided significant evidence for lineage differentiation in wild B. juncea. The high differentiation between the two lineages was, perhaps, due to limited gene flow (Nm?=?0.301) of this species. The analysis of molecular variance with distances among individuals corrected for the dominant nature of SSRs showed that most of the variation (59%) occurred within populations, and the remaining 41% variance was attributed to differences among populations. The distribution of diversity across China was significantly geographically dependent. NJ cluster analysis, based on genetic distance, grouped populations geographically, which further corroborated spatial pattern of two lineages. Based on these results, two routes were proposed for the migration of wild B. juncea in China after its origin from northwest China, heading east along the Yellow River or Yangtze River, respectively. We concluded that China, especially the northwest, is one of the primary origins of B. juncea. 相似文献
5.
Ali Gharghani Zabihollah Zamani Alireza Talaie Nnadozie C. Oraguzie Reza Fatahi Hassan Hajnajari Claudia Wiedow Susan E. Gardiner 《Genetic Resources and Crop Evolution》2009,56(6):829-842
In order to shed light on the role of Iran in apple evolution and domestication, we chose to investigate the relationships
of a collection of 159 accessions of wild and domesticated apples including Iranian indigenous apple cultivars and landraces,
selected wild species, and old apple scion and rootstock cultivars from different parts of the world. The majority of the
wild species belonged to M. sieversii, which is widely believed to be the main maternal wild ancestor of domestic apples, from Kazakhstan and M. orientalis, which is one of the probable minor ancestors of domestic apples, from Turkey and Russia located on the east and west of
Iran, respectively. The accessions were assigned into six arbitrary populations for the purpose of generating information
on genetic parameters. Nine simple sequence repeat (SSR) loci selected from previous studies in apple were screened over DNA
extracted from all the accessions. Results showed that all SSR loci displayed a very high degree of polymorphism with 11–25
alleles per locus. In total, there were 153 alleles across all loci with an average of 17 alleles per locus. The SSR allelic
data were then used for estimation of population genetic parameters, including genetic variation statistics, F-statistics,
gene flow, genetic identity, genetic distance and then cluster analysis using POPGENE 1.32 software. The F-statistics and
gene flow in particular, showed that there was more intra-population than between population variation. The genetic identity
and genetic distance estimates, and the dendrogram generated from the un-weighted pair group arithmetic average (UPGMA) method
of cluster analysis showed that the Iranian cultivars and landraces were more closely related to M. sieversii from Central Asia (east of Iran) and M. orientalis native to Turkey and Russia than to other accessions of Malus species. Also, the old apple cultivars from different parts of the world have a closer genetic relationship to M. sieversii, M. orientalis and the Iranian apples, than to other wild species. Based on these results, we suggest that the Iranian apples may occupy
an intermediate position between the domesticated varieties and wild species. We propose that Iran could be one of the major
players in apples’ domestication and transfer from Central Asia to the western countries. 相似文献
6.
Stina Christensen Roland von Bothmer Gert Poulsen Lorenzo Maggioni Marianne Phillip Bente Anni Andersen Rikke Bagger Jørgensen 《Genetic Resources and Crop Evolution》2011,58(5):657-666
AFLP markers were used to characterize diversity and asses the genetic structure among 17 accessions of kale landraces, cultivars
and wild populations from Europe. The range of average gene diversity in accessions was 0.11–0.27. Several landraces showed
higher levels of diversity than the wild populations and one cultivar had the lowest diversity measures. The landraces that
were most genetically diverse were from areas where kales are known to be extensively grown, suggesting in situ conservation in these areas as a supplement to storage of seeds in gene banks. An analysis of molecular variance (AMOVA)
showed that 62% of the total variation was found within accessions. For most accessions, genetic distance was not related
to geographic distance. Similarities among accessions were probably not caused by recent gene flow since they were widely
separated geographically; more likely the relationship among them is due to seed dispersal through human interactions. Our
results indicate that a kale population found in a natural habitat in Denmark was probably not truly wild but most likely
an escape from a cultivated Danish kale that had subsequently become naturalized. 相似文献
7.
Interspecific gene flow from crop species into wild relatives may compromise the genetic integrity of native species and in
the case of transgenic crops lead to the escape of transgenes into natural populations. Approximately 72% of the upland cotton
(Gossypium hirsutum L.) acreage grown in the United States in 2000 utilized transgenic cultivars. The closest relative of G. hirsutum is G. tomentosum Nuttall ex Seeman, endemic to the Hawaiian archipelago. Because these two species are fully interfertile, cultivation of
transgenic G. hirsutum in the Hawaiian Islands is restricted. We investigated the possibility of identifying AFLP genetic markers that are diagnostic
for each species and thus could be used in future studies to detect introgression between them. In addition, we were interested
in comparing levels and geographic patterns of AFLP diversity in G. tomentosum to previous estimates using allozyme data. AFLP analysis led to the detection of 11 and 16 species-specific markers for G. tomentosum and G. hirsutum, respectively. These species-specific AFLP markers will be useful for detecting gene flow between G. hirsutum and G. tomentosum that has occurred in the past and thus might occur in the future if the restrictions on cultivation of transgenic G. hirsutum are relaxed in the Hawaiian Islands. Little genetic diversity and limited geographic patterning were discovered using AFLP
markers, consistent with data from previous allozyme studies. 相似文献
8.
The wild soybean, an annual self-pollinating plant, is the progenitor of soybeans and is extensively distributed in the Far
East of Russia, the Korea peninsula, China and Japan. Geographically, Japan is surrounded by sea and insulated from China.
We preliminarily evaluate whether the Japanese and Chinese wild soybean germplasm pools are genetically differentiated from
each other using SSR markers. The results showed that the two pools have great genetic differentiation. Some loci presented
obvious differences in mean genetic divergence (GST) value between the two pools. The GST among the geographic regions in China was higher than that in Japan. The average within-geographic region gene diversity
values (HS) in the two pools were completely identical and thus the genetic difference between the two pools was mostly attributed to
the relatively high level of between-geographic region gene diversity (DST) in China. We suggest that Japanese and Chinese wild soybeans should be comparatively independently evolving in phylogeny. 相似文献
9.
Jaime Prohens Gregory J. Anderson F. Javier Herraiz Gabriel Bernardello Arnoldo Santos-Guerra Daniel Crawford Fernando Nuez 《Genetic Resources and Crop Evolution》2007,54(3):451-464
Solanum vespertilio Aiton and Solanum lidii Sunding are endemic, endangered wild species from the Canary Islands. These species are of potential value for eggplant (S. melongena) breeding, given that they are part of the secondary genepool of this crop. We study genetic diversity with amplified fragment
length polymorphisms (AFLPs) markers from 5 populations of S. vespertilio (47 samples) and 3 of S. lidii (26 samples). Five related African species (S. dasyphyllum Schumach. et Thonn., S. delagoense Dunal, S. campylacanthum Hochst., S. panduriforme E. Mey, S. aff. violaceum Ortega) were also included in the analysis. A total of 235 AFLP markers included 178 and 156 that were polymorphic in S. vespertilio and S. lidii, respectively. Analysis of genetic distance, phenograms, and principal component plots showed that these rare Canarian species
are differentiated (G
ST = 0.412) from the continental materials and that Solanum vespertilio is more distinct to its African congeners than is S. lidii. There is a relatively high level of differentiation between the two species (G
ST = 0.373), that presumably reflects geographic restrictions (S. lidii to Gran Canaria; S. vespertilio essentially to Tenerife). However, both species have similar levels of total diversity. We speculate that the combination
of the many unusual reproductive features (andromonoecy, zygomorphy, heteranthery and weak enantiostyly in S. vespertilio) help explain genetic diversity that is high for self compatible species. The high genetic diversity may also indicate populations
were larger in the past. A decrease in population size could contribute to the relatively low genetic differentiation among
the populations. The data presented herein provide the foundation for initiation of ex situ and in situ conservation programs
for these wild relatives of eggplant.
This paper is dedicated to the memory of Dr. Richard N. Lester, who made significant contributions to the taxonomy, biosystematics
and conservation of genetic resources of African species of Solanum. 相似文献
10.
There is a need to understand whether weed genetic diversity is the same among different populations, especially between those
exposed to herbicide selection and other without exposure history. Inter-simple sequence repeat (ISSR) were used to assess
level and patterns of genetic diversity in wild Brassica juncea (L.) Czern. et Coss. populations. A total of 93 plants from 24 wild populations in China were analysed by eight primers resulting
in 86 highly reproducible ISSR bands. The analysis of molecular variance (AMOVA) with distances among individuals corrected
for the dominant nature of ISSRs showed that most of the variation (54.09%) occurred among populations, and the remaining
45.91% variance was attributed to differences among individuals within populations. The high differentiation was, perhaps,
due to limited gene flow (Nm < 1.0) of this species. Though highest gene diversity was observed in resistant B. juncea population, the overall distribution of diversity across China was not geographic dependent. High F
ST value (0.541) corroborated AMOVA partitioning and provided significant evidence for population differentiation in wild B. juncea. UPGMA cluster analyses, based on Nei’s genetic distance, revealed grouping pattern geographically. Based on these results,
the factors affect weed population genetic diversity and implication for herbicide resistance evolution were discussed in
the context of transgenic crops advent and increasing herbicide usage in China. 相似文献
11.
Genetic diversity was investigated in 73 accessions of emmer wheat (Triticum dicoccon Schrank) from 11 geographical regions using a set of 29 simple-sequence repeat (SSR or microsatellite) markers, representing
at least two markers for each chromosome. The SSR primers amplified a total of 357 different alleles with an average of 12.31
alleles per locus. The number of fragments detected by each primer ranged between 6 (Xgwm1066) and 21 (Xgwm268). Null alleles were detected in nine of the 29 primers used. A high level of gene diversity index was observed. Across the
29 primers, gene diversity ranged from 0.60 (Xgwm46) to 0.94 (Xgwm655), with a mean of 0.82. There was a highly significant correlation (r=0.882; p<0.01) between gene diversity index and the number of loci, showing the number of loci per se is a strong indicator of diversity. Analysis of genetic diversity within and among eleven geographical regions revealed most
of the genetic diversity of the total sample resided within regions. The coefficient of gene differentiation (Gst = 0.27)
showed that the genetic variation within and among the 11 geographical regions was 73 and 27%, respectively. High value of
mean number of alleles per locus was found in Iran (4.86) followed by Morocco (4.10) and Armenia (4.03). On the contrary,
lower mean number of alleles per locus was detected in Yemen (2.83). The average gene diversity index across regions ranged
from 0.52 (Slovakia) to 0.67 (Morocco) with an average of 0.60. Multivariate techniques of principal component analysis and
clustering were employed to examine genetic relationship among the 73 emmer wheat accessions vis-à-vis geographical regions
of collections. The genetic distance coefficients for all possible 55 pairs of regional comparisons ranged from 0.63 (between
Iran and Armenia, Georgia and Azerbaijan, Georgia and Slovakia) to 0.97 (between Morocco and Yemen, Spain and Georgia, and
Turkey and Iran) with a mean of 0.82. From the PCA results, a two dimensional plot of PC1 versus PC2 was constructed. The
scatter plot of the first two principal components which explained altogether 27% of the total variation depicted the presence
of a clear pattern of geographical differentiation except in few cases like accessions from Caucasian region. Similar pattern
of genetic relationships among accessions was observed in cluster analysis. The study provided genetic information of emmer
wheat in relation to geographical regions of origin. The information could be utilized in crop improvement, germplasm conservation
programs, and in further investigation. 相似文献
12.
O. Ozbek E. Millet Y. Anikster O. Arslan M. Feldman 《Genetic Resources and Crop Evolution》2007,54(7):1587-1598
The aim of the present study was to assess the genetic variation in several Israeli and Turkish populations of wild emmer
wheat, Triticum turgidum ssp. dicoccoides, the progenitor of most domesticated wheat. Single spikes were collected in 2002 from 60 plants that grew in six different
habitats in Ammiad, northeastern Israel (8–12 plants from each habitat), and in 1998 from 56 plants that grew in seven different
habitats in Diyarbakir, southeastern Turkey (8 plants from each habitat). Seeds were planted in a nursery and DNA was extracted
from every plant and analyzed by the fluorescent-based amplified fragment length polymorphism (AFLP) method. Seven primer
combinations produced 788 discernible loci of which 48.6% were polymorphic in Israel and 40.5% in Turkey. The genetic diversity
estimates P (frequency of polymorphic loci) and He (gene diversity) were higher in Ammiad than in Diyarbakir (means of P = 0.34 and He = 0.13 in Ammiad vs. P = 0.20 and He = 0.08 in Diyarbakir). Ammiad populations contained more unique alleles than Diyarbakir populations. The relative genetic
diversity estimates (θ) values were 0.188 in Ammiad and 0.407 in Diyarbakir, suggesting better differentiation of the populations in Turkey. Genetic
distance was larger between Israeli and Turkish populations than between populations of each country. The data indicate that
the Israeli and Turkish populations are considerably diverged and that the Israeli populations are more polymorphic than the
Turkish ones, having a larger within-populations genetic variation than among-populations one. The significance of the results
in relation to the differentiation pattern of wild emmer in the Near East is discussed. 相似文献
13.
Gabriella Sonnante Anna Vittoria Carluccio Angelo De Paolis Domenico Pignone 《Genetic Resources and Crop Evolution》2008,55(7):1029-1046
A set of 24 microsatellite markers was identified in the artichoke genome, using various approaches. A genomic library allowed
the development of 14 SSR markers, whereas the other 10 were obtained from gene intron/UTR regions or from other species.
Allelic variation was scored in C. cardunculus (artichoke, cultivated cardoon, and wild cardoon) samples, and in other wild Cynara allies. For the 23 polymorphic loci, a total of 165 alleles were scored, 135 of which in the artichoke primary genepool,
and the remaining ones in the other Cynara species. Some allele combinations were able to identify artichoke varietal types, and some alleles were unique to specific
groups. This makes these markers potentially useful in product traceability and in contributing to the saturation of genetic
maps. The percentage of shared alleles between C. cardunculus taxonomic groups, and Nei’s genetic distances indicated that wild cardoons from the Eastern Mediterranean were more closely
related to artichoke and less to cultivated cardoon in comparison to wild cardoons from the Western Mediterranean, and the
genetic distance between the two wild cardoon genepools was rather high. The UPGMA dendrogram based on Nei’s genetic distances
revealed that artichokes formed a fairly defined cluster, whereas Eastern wild cardoons occupied another branch, and Western
wild cardoons were clustered together with cultivated cardoons. The transferability of microsatellite markers to other Cynara wild species was quite good. Sequencing alleles at three loci showed that, apart from microsatellite length variation, point
mutations and insertion/deletions were quite abundant especially when comparing C. cardunculus to the other Cynara species. In the sequenced regions, some SNPs were identified which distinguished artichoke on one side, and cultivated and
wild cardoon on the other, while other SNPs were apportioned according to the geographic distribution of Cynara wild species. 相似文献
14.
Azadeh Akhavan Hojjatollah Saeidi Mohammad Reza Rahiminejad 《Genetic Resources and Crop Evolution》2010,57(3):415-422
Microsatellite markers were used to analyse the genetic diversity of 120 individuals of 20 weedy/wild populations of Secale cereale collected all around Iran. High levels of diversity, with an average number of seven alleles per locus (ranging up to 11)
and high level polymorphism with polymorphism rate averaging 0.645 (between populations) and 0.364 (within populations) were
observed. The Northwestern populations showed the highest and the Northern populations showed the lowest polymorphism and
diversity. One population was notably more similar to five of the S.
strictum used as outgroups. No taxon or geographic specific marker was detected, suggesting high gene flow between the populations,
however some groupings which can be related to the subspecies, were evident. This survey showed the high genetic diversity
within the Iranian rye genepool as an important source for crop breeders, and indicated that there is value in sampling for
useful genes for crops improvement. 相似文献
15.
AFLP (Amplified Fragment Length Polymorphisms) and SSR (Simple Sequence Repeat) markers were utilized to assess genetic diversity and relatedness between Vigna unguiculata subspecies. Three AFLP primer combinations and 10 SSR primer sets successfully identified closely related accessions, and the presence of heterogeneity in some accessions. AFLP methodology was successful in separating different species of Vigna. However, the level of intra-subspecies variation was as great as was the interspecies variation with both marker methods. The number of markers employed was insufficient to successfully group the subspecies into distinct clades. 相似文献
16.
Hironori Katayama Shiho Adachi Toshiya Yamamoto Chiyomi Uematsu 《Genetic Resources and Crop Evolution》2007,54(7):1573-1585
Iwateyamanashi (Pyrus ussuriensis var. aromatica) is one of the Pyrus species which grows wild in Japan. The number of Iwateyamanashi trees has been decreasing, so conservation and evaluation
is urgently needed. Over 500 accessions of Pyrus species collected from Iwate in northern Tohoku region are maintained at Kobe University as an Iwateyamanashi germplasm collection.
In order to investigate the genetic diversity, five SSR (simple sequence repeat) markers, developed from Japanese and European
pear were examined for 86 Pyrus individuals including 58 accessions from Iwate. These SSR loci could discriminate between all the Iwate accessions except
for 10 that bear seedless fruit, as well as determine the genetic diversity in Iwateyamanashi germplasms. High levels of variation
were detected in 41 alleles and the mean observed heterozygosity across 5 loci was 0.50 for the Iwate accessions. Seedless
accessions sharing identical SSR genotype with the local pear variety “Iwatetanenashi” were supposed to have been propagated
vegetatively via grafting. In an UPGMA phenogram, Japanese pear varieties (P. pyrifolia) were clustered into two groups with some Iwate accessions including seedless ones. Another 38 Iwate accessions were not
clustered clearly, and there was no clear relationship between these accessions and geographical distribution or morphological
characters. Allele frequency revealed that the Iwate accessions were genetically more divergent than the Japanese pear varieties.
Most Japanese pears possessed a 219 bp deletion at a spacer region between the accD and psaI genes in the chloroplast DNA (cpDNA), but other Pyrus species and two Iwateyamanashi trees did not. In the Iwate accessions, 79.3% had a deletion type cpDNA and others had a standard
type cpDNA without deletion. These results are indicative of the wide range of genetic diversity in the Iwate accessions which
include Japanese pear varieties. A combination of SSR and cpDNA analyses revealed high heterogeneity in Iwateyamanashi and
coexistence of Iwateyamanashi and hybrid progeny with P. pyrifolia. These could be reasons for the wide range of continuous morphological variation described previously. 相似文献
17.
Yvonne Lokko Alfred Dixon Sam Offei Eric Danquah Martin Fregene 《Genetic Resources and Crop Evolution》2006,53(7):1441-1453
A study was conducted to determine the extent of genetic diversity among African cassava (Manihot esculenta Crantz) accessions resistant to the cassava mosaic virus disease (CMD), using simple sequence repeat (SSR) markers. The accessions
included a breeding stock (clone 58308), five improved lines, 62 CMD resistant and 10 CMD susceptible landraces. Genetic diversity
was assessed among accessions in five cluster groups derived from UPGMA analysis on data from 18 SSR primer pairs. Average
gene diversity, He, was high in all cluster groups, with an average heterozygosity of 0.591 ± 0.061. The estimator of inbreeding
Fis revealed a low level of inbreeding within groups and averaged −0.262 ± 0.142. Gene diversity among all accessions was
51.4% and gene diversity within cluster groups was 46.6%, while 4.8% was due to diversity between the different cluster groups.
The amount of genetic differentiation measured by Gst and Fst were 9.6% and 12.1% respectively, indicating a weak genetic
structure. 相似文献
18.
Tibet is the highest Plateau in China and the world, however wild soybean has been found in its southeastern fringe region
adjacent to the northwest of Yunnan Province. Tibetan wild soybean was distributed only in the Gongrigabuqu-River Gorge in
southeast Tibet. This regional plant species belong to the flora of Himalayan-Hengduan Mountains, which comprises composite
elements of ancient arcto-tertiary flora, tropical and semitropical flora. To date, few studies have been carried out on Tibetan
wild soybean. Studying Tibetan wild soybean together with other regional ones helps to understand the history of the origin
and dissemination of wild soybean species in China. Here we reported the status of genetic diversity in Tibetan wild soybean
and the genetic relationship between Tibetan and other regional wild soybeans revealed by nuclear SSR markers. The results
showed that the Tibetan wild soybean sample was significantly differentiated from other regional ones, as characterized by
the lowest mean allelic richness (
[^(\textr)] {\hat{\text{r}}} = 1.40) and gene diversity (H
e = 0.130) and the highest ratios of regionally unique alleles (63.26%) and fixed alleles (46.94%). These genetic attributes
suggested that Tibetan wild soybean may have undergone severe adaptation selection for the plateau climate and ecogeographical
conditions, and had less genetic exchange with inland populations. The regional population south of the Changjiang River (Central
and South China) showed higher genetic richness. UPGMA cluster analysis revealed two large geographical groups, Tibetan and
inland, and revealed closer relationship among the eastern populations, which suggested that the dissemination of this species
in the eastern part of China might be rapider. 相似文献
19.
20.
Tileye Feyissa Hilde Nybom Igor V. Bartish Margareta Welander 《Genetic Resources and Crop Evolution》2007,54(5):947-958
Genetic diversity within and among 12 populations of the dioecious tropical tree species Hagenia abyssinica (Bruce) J.F. Gmel. in Ethiopia was examined with eight inter simple sequence repeat (ISSR) primers. A total of 104 clearly
scorable bands were generated, among which 84 (81%) were polymorphic. Jaccard similarity coefficient was calculated for pairwise
comparisons among all 120 individuals and ranged from 0.30 to 0.88 while average within-population similarity ranged from
0.53 to 0.66. Within-population variability was estimated as percentage polymorphic loci (ranging from 52% to 87%), Shannon’s
information index (0.30–0.50) and Nei’s genetic diversity (0.21–0.35). The highest variability values were obtained for one
recently planted population and for one wild population growing in an undisturbed primary forest area. Significant overall
differentiation among populations was detected by both Shannon’s information index (0.26) and G
ST (0.25). Relatedness among samples was estimated with a principal coordinate analysis, and relatedness among populations was
estimated with a cluster analysis (UPGMA). A Mantel test indicated a significant association between genetic and geographic
distances, and an autocorrelation analysis showed significant evidence of gene flow over distances up to 30 km. This study
is the first of its kind for H. abyssinica, which has decreased recently in Ethiopia and now must be regarded as an endangered species. Both within-population and between-population
diversity estimates are typical of outcrossing, longlived and late successional species, suggesting that recent anthropogenic
disturbances have not yet had much impact on population genetic parameters. DNA marker data can, however, be used to identify
the most suitable sites for in situ conservation and for collection of material for establishment of genebanks and plant improvement programs. 相似文献