Comparison of the allozyme diversity in several populations of Chamaecyparisformosensis and Chamaecyparistaiwanensis

1994 ◽  
Vol 24 (10) ◽  
pp. 2128-2134 ◽  
Author(s):  
Tsan-Piao Lin ◽  
Tzen-Yu Lee ◽  
Li-Feng Yang ◽  
Yong-Ly Chung ◽  
Jenq-Chuan Yang
Keyword(s):  
Population Variation ◽  
Fixation Index ◽  
Effective Number ◽  
Allozyme Diversity ◽  
Polymorphic Loci ◽  
Average Percentage ◽  
Expected Heterozygosity ◽  
Hardy Weinberg Equilibrium ◽  
Different Populations ◽  
One Year

Genetic diversity within and genetic differentiation among three populations of Chamaecyparisformosensis Matsum. and two populations of Chamaecyparistaiwanensis Masam. & Suzuki were investigated using one-year-old seedlings collected from central and northern Taiwan. For C. formosensis 330 seedlings from 33 seed trees were used, while for C. taiwanensis 260 seedlings from 26 seed trees were used. Eleven enzyme systems were investigated. In C. formosensis, 5 of the 21 loci examined were polymorphic. The average percentage of polymorphic loci per population was 20.6% at the 99% criterion for polymorphism. Mean expected heterozygosity ranged from 0.079 to 0.100 in the different populations. On average, there were 6.6 to 9.2% heterozygous loci per individual and 1.24 to 1.29 alleles per locus; the effective number of alleles per locus ranged from 1.09 to 1.11. In C. taiwanensis, 7 of the 20 loci examined were polymorphic and the average percentage of polymorphic loci per population was 22.5%. Mean expected heterozygosity ranged from 0.044 to 0.060. On average there were 4.5 to 5.6% heterozygous loci per individual and 1.45 alleles per locus; the effective number of alleles per locus ranged from 1.05 to 1.08. The surprisingly low expected heterozygosity and percentage of polymorphic loci compared with other conifer probably reflects the insular nature of these species. Partitioning the genetic variability into within- and among-population components with F-statistics led to an estimate of within-population variation of 95% of the total variation in both C. formosensis and C. taiwanensis. Chamaecyparisformosensis had a positive fixation index (0.109) that was significantly different from zero at the 5% level, indicating that most loci have slightly higher frequencies of homozygotes. Chamaecyparistaiwanensis, however, had a fixation index close to zero (0.036), which suggests that most loci are in Hardy–Weinberg equilibrium. The genetic distance between C. formosensis and C. taiwanensis was 0.70, which clearly separates these two species.

scholarly journals Inter- and intra-population variation of local maize (Zea mays L.) populations from Slovakia and Czech Republic

2008 ◽  
Vol 43 (No. 1) ◽  
pp. 7-15 ◽  
Author(s):  
P. Múdry ◽  
J. Kraic
Keyword(s):  
Zea Mays ◽  
Genetic Variation ◽  
Czech Republic ◽  
Population Variation ◽  
Polymorphic Loci ◽  
Maize Populations ◽  
Expected Heterozygosity ◽  
Isoenzyme Polymorphism ◽  
New Alleles

Evaluation of genetic variation was performed within 62 local maize populations originating from Slovakia and Czech Republic. In total 48 alleles at 22 analyzed isoenzyme loci with an average of 2.2 alleles per locus were revealed. The percentage of polymorphic loci ranged from 14% to 59% and the frequencies of detected alleles varied from null to four per locus. No polymorphism was detected at the loci <i>Dia2</i>, <i>Got3</i>, <i>Mdh4</i>, <i>Mmm</i>, and <i>Pgm1</i>. The highest number of alleles (four) was detected at loci <i>Acp1</i>, <i>Cat3</i>, <i>Pgm2</i>. No new alleles were identified, nevertheless the frequency of seven alleles was only about 1%. The expected heterozygosity ranged from null to 0.492 with an average of 0.197. The revealed isoenzyme polymorphism confirmed that all analyzed populations were heterogeneous and as many as 17 of them were completely heterogeneous. None of the analyzed populations was identical in the frequency of alleles at all 22 analyzed loci.

Genetic analysis of Cheirostylis species based on microsatellite markers

2014 ◽  
Vol 13 (3) ◽  
pp. 286-289 ◽  
Author(s):  
Supajit Sraphet ◽  
Anuwat Saengsri ◽  
Duncan R. Smith ◽  
Kanokporn Triwitayakorn
Keyword(s):  
Genetic Analysis ◽  
Microsatellite Markers ◽  
Genomic Dna ◽  
Polymorphic Loci ◽  
Dna Library ◽  
Expected Heterozygosity ◽  
Unknown Species ◽  
Genomic Dna Library ◽  
Hardy Weinberg Equilibrium ◽  
Conservation Plan

Microsatellite markers specific to Cheirostylis yunnanensis Rolfe were developed using an enriched genomic DNA library technique. The library was constructed using (AG)20 and (CAG)20 oligonucleotide repeats. A total of 48 primer pairs were designed and tested with 48 C. yunnanensis Rolfe samples, resulting in 11 polymorphic loci. The number of alleles per locus ranged from 2 to 12, with an average of six alleles. The observed and expected heterozygosity ranged from 0.0426 to 0.8085 and 0.0421 to 0.9078, respectively. Of the 11 polymorphic loci, three showed a significant deviation from Hardy–Weinberg equilibrium and one exhibited linkage disequilibrium. Cross-species amplification was tested with five samples of Cheirostylis of unknown species resulting in eight loci that could be amplified, with the number of alleles ranging from one to two. The microsatellite markers developed in this study will be useful for the genetic analysis of C. yunnanensis in order to differentiate species as well as to establish a conservation plan for this species.

Genetic structure and variability in jack pine populations: effects of insularity

1992 ◽  
Vol 22 (12) ◽  
pp. 1958-1965 ◽  
Author(s):  
Sylvie Gauthier ◽  
Jean-Pierre Simon ◽  
Yves Bergeron
Keyword(s):  
Genetic Structure ◽  
Regional Scale ◽  
Fire Regimes ◽  
Jack Pine ◽  
Fixation Index ◽  
Significant Heterogeneity ◽  
Island Populations ◽  
Selective Pressures ◽  
Expected Heterozygosity ◽  
Hardy Weinberg Equilibrium

To determine the effects of insularity on the genetic structure and variability of jack pine (Pinusbanksiana Lamb.) populations at a regional scale, stands from two different landscapes were studied: two islands in a lake and two mainland areas. The two landscapes have been affected by different fire regimes. The genetic structure and variability of the four populations were analyzed using cellulose acetate gel electrophoresis of 11 enzyme systems. The analysis of 22 loci showed an average polymorphism of 60.0%, a mean of 2.3 alleles per locus, a mean of 1.185 effective alleles per locus, and an observed level of heterozygosity of 0.171. The Fis values (i.e., fixation index of individuals relative to their population) for all but two loci indicated an excess of heterozygotes compared with the expected numbers under Hardy–Weinberg equilibrium. The genetic differentiation among populations was weak (Fst = 0.018). There were no significant differences among the four populations for five genetic parameters (mean number of alleles per locus, mean number of effective alleles per locus, percentage of polymorphic loci, and observed or expected heterozygosity). Although the allelic frequencies were homogeneous between island populations, a significant heterogeneity in allele frequencies was observed between mainland populations. The results suggest that gene flow in island populations is sufficiently high to maintain a level of genetic variability similar to that found in mainland populations and to counteract the effect of isolation and differential selective pressures resulting from different disturbance regimes.

scholarly journals Exploration of the Exogenous Male Yak Introduction Breeding Model and its Effects on Tibetan Small-Sized Family Farms

2021 ◽  
Vol 41 (01) ◽  
pp. 137-141
Author(s):  
Basang Wang-Dui
Keyword(s):  
Adult Male ◽  
Management Model ◽  
Fixation Index ◽  
Small Scale ◽  
Family Farms ◽  
Male Adult ◽  
Expected Heterozygosity ◽  
Hardy Weinberg Equilibrium ◽  
Husbandry System ◽  
Inbreeding Level

A total of three family farms including Village No. 9 in Nima township, Nerong Naqu County (NQA); Village No. 11 in Nima township, Nerong Naqu County (NQB); and Yare township, Gegi County, Ali District (GJ) from three ecology yak populations (EYP) were selected for this study to identify the most optimized mode of exogenous male adult yak introduction (EMI) within EYP for solving the inbreeding problem caused by the small-scale yak husbandry system. Exogenous adult male yaks from the same EYP with different proportions (100% to NQA, 50% to NQB, and 0% to GJ) were introduced, and 10 microsatellites were used to detect the genetic diversity of these populations before (in 2017) and after (in 2019) the introduction of exogenous adult male yaks (EMI). Results showed that the divergence between the observed and the expected heterozygosity of the NQA and NQB populations was reduced in 2019, while the number of markers significantly deviating from Hardy–Weinberg equilibrium (P<0.05) and FIS (inbreeding coefficient) within populations decreased compared with that in 2017. In contrast, the FIS of GJ population without EMI continued to increase (from 0.011 to 0.033) over the years 2017 to 2019. Moreover, genetic differences between the populations (Pairwise Fixation index, FST) showed that EMI increased the genetic divergence between populations. Overall, this study shows that the introduction of exogenous male adult yaks not only effectively reduces the degree of population deviation from equilibrium but also decreases the inbreeding level within the population within a few generations. This study also provides a valuable management model for stable yak production on small sized family farms

scholarly journals GENETIC POLYMORPHISM AND SEED DIFFERENTIATION SCOTS PINE SEEDS OF DIFFERENT SELECTION CATEGORIES USING ISSR-MARKERS

2020 ◽  
Vol 9 (4) ◽  
pp. 15-24
Author(s):  
Olga Sheikina ◽  
Tat'yana Krivorotova ◽  
Yuriy Gladkov
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Polymerase Chain Reaction Method ◽  
Issr Markers ◽  
Effective Number ◽  
Polymorphic Loci ◽  
Expected Heterozygosity ◽  
Polymerase Chain ◽  
The Republic ◽  
Issr Primers

The purpose of the study is a comparative assessment of the genetic diversity and differentiation of common pine seeds of different breeding categories. The object of the study was seeds harvested on permanent forest seed plots and clone forest seed plantations in the Penza region, the Chuvash Republic and the Republic of Mari El. A polymerase chain reaction method with ISSR primers has been used to assess the level of genetic diversity and differentiation. A total of 250 loci have been amplified using 6 ISSR primers, 210 of which were polymorphic ones. The studied seed batches were characterized by different levels of genetic variation. Indicators of genetic diversity of seeds (improved breeding category) have varied within the following limits: the percentage of polymorphic loci from 56.3 to 72.6; the number of alleles per locus from 1.56 to 1.73; effective number of alleles from 1.26 to 1.38; expected heterozygosity from 0.17 to 0.23. Seeds of the normal selection category are characterized by the following indicators of genetic diversity: the percentage of polymorphic loci is 57.2–72.6; the number of alleles per locus 1.57–1.68; the effective number of alleles is 1.25–1.33; expected heterozygosity - 0.16–0.19. Dependence of the level of genetic diversity on the selection category of seeds has not been identified. Generalized indicators of the genetic diversity of improved seeds have been close or higher in comparison with normal seeds. Ney's genetic distance between 8 batches of seeds has ranged from 0.027 to 0.113. The genetic subdivision index (GSI) was 0.25. Therefore, a large proportion of the genetic variation is located inside seed batches (75%).

scholarly journals Genetic variability of Scots pine (Pinus sylvestris L.) in maternal regions of provenance

2015 ◽  
Vol 57 (2) ◽  
pp. 112-119 ◽  
Author(s):  
Paweł Przybylski ◽  
Jan Matras ◽  
Małgorzata Sułkowska
Keyword(s):  
Genetic Variability ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Genetic Parameters ◽  
Fixation Index ◽  
Effective Number ◽  
Expected Number ◽  
Expected Heterozygosity ◽  
Rare Alleles ◽  
Fixation Indices

Abstract The analysis of chosen selected Scots Pine (Pinus sylvestris L.), populations representing different seed regions: 107 (Międzyzdroje), 305 (Woziwoda), 206 (Strzałowo), 208 (Białowieża), 504 (Bolesławiec), 606 (Józefów) were performed using 10 isoensyme markers: Gdh (E.C.1.4.1.2), Sdh-A, Sdh-B (E.C.1.1.1.25), Pgd-B (E.C.1.1.1.44), Mdh-A, Mdh-C (E.C.1.1.1.37), Got-A, Got-B, Got-C (E.C.2.6.1.1), Dia-C (E.C.1.8.1.4). There were calculated following genetic parameters: allelic frequencies, observed and expected heterozygosities, and Wright’s fixation indexes. In populations, the results of analysis indicated presence of rare alleles. In all study populations, the average effective number of alleles per locus was 1.46 and was lower than expected number of alleles per locus of 1.93. The results for the effective number of alleles of the population per locus were as follows: Strzałowo and Białowieża 1.54, Bolesławiec 1.48, Jozefów 1.44, Świnoujście 1.42, Woziwoda 1.35. Average observed heterozygosity in the studied populations was calculated at the level of 0.26 and it was lower than the expected heterozygosity at 0.28. For populations, the level of heterozygosities were as follow: Strzałowo 0.35, Bolesławiec and Białowieża 0.25, Józefów 0.27, Świnoujście 0.23, Woziwoda 0.26. In particular loci level of heterozygosity was different, as the most heterozygous Mdh-C locus was estimated, while minimum Got-C. Significant differences in allele frequency of Hardy-Weinberg deviation equilibrium were found in 10 cases: Strzałowo (Got-C), Bolesławiec (Got-B), Białowieża (Got-B, Gdh), Józefów (Mdh-C), Międzyzdroje (Got-B, Got-C, Mdh-C), Woziwoda (Got-C, Gdh). All studied populations had a lower effective number of alleles per locus (Ne) comparing to the observed number of alleles (Na). Wright’s fixation indices were negative for populations: Strzałowo (-0.09), Józefów (-0.03), Międzyzdroje (-0.01) and positive for: Białowieża (0.12), Woziwoda and Bolesławiec (0.07). The extremely high Wright’s fixation index (0.12) was observed for Białowieża population.

Sex-biased dispersal of greater long-tailed hamster (Tscherskia triton) revealed by microsatellites

2005 ◽  
Vol 83 (6) ◽  
pp. 773-779 ◽  
Author(s):  
Mingjing Song ◽  
Zhibin Zhang ◽  
Karsten Neumann ◽  
Rolf Gattermann
Keyword(s):  
Genetic Diversity ◽  
Allelic Richness ◽  
Allelic Diversity ◽  
Hebei Province ◽  
Effective Number ◽  
Republic Of China ◽  
Allele Number ◽  
Expected Heterozygosity ◽  
Hardy Weinberg Equilibrium ◽  
Polymorphic Microsatellite

For 2 consecutive years we studied the effect of dispersal on the genetic diversity of greater long-tailed hamsters (Tscherskia triton (de Winton, 1899)) in farmland habitat, Hebei Province, People's Republic of China. Level of genetic diversity was estimated by analyzing six highly polymorphic microsatellite loci in terms of mean d2, allele number, allelic diversity, effective number of alleles, allelic richness, average observed heterozygosity, and expected heterozygosity. The genetic diversity in populations from both two sites and 2 years indicated that the males contained higher levels of genetic diversity than the females, which supported our prediction that male-biased dispersal increased population genetic diversity. We also found significant departures from Hardy–Weinberg equilibrium and a reduction in genetic diversity in samples from a partially isolated site, which was probably due to genetic drift, inbreeding, or a combination of these factors.

Allozyme variability in natural populations of green alder (Alnus crispa) in Quebec

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 345-352 ◽  
Author(s):  
J. Bousquet ◽  
W. M. Cheliak ◽  
M. Lalonde
Keyword(s):  
Natural Populations ◽  
Outcrossing Rate ◽  
Polymorphic Loci ◽  
Alnus Crispa ◽  
Model Average ◽  
Expected Heterozygosity ◽  
Green Alder ◽  
Hardy Weinberg Equilibrium ◽  
Fixation Indices ◽  
Sexually Mature

Vegetative and sexual tissues from 22 populations of Alnus crispa (Ait.) Pursh (green alder, Betulaceae) in Quebec were analyzed for electrophoretically demonstrable diversity of 11 enzymes encoded by 16 structural loci in sexually mature populations. Of these 16 loci, 9 were found polymorphic. A total of 28 different alleles were detected with no more than three alleles per locus. No two-locus linkage disequilibrium was observed between eight polymorphic loci analyzed. Assuming a diploid model, average level of expected heterozygosity was 0.14 in the mature generation, with nearly all populations in Hardy–Weinberg equilibrium for the set of polymorphic loci investigated. Mean outcrossing rate was 0.95. Fixation indices revealed low inbreeding with no specific subpopulation structure. Hence, an important level of gene flow would exist within the populations. Without any strong evidence for polyploidy, and in the light of results obtained, the species could be classified equally well as a diploid or a diploidized allotetraploid. Key words: actinorhizal plant, alder, allozymes, Alnus, fixation indices, heterozygosity, outcrossing rate, polyploidy.

Genetic diversity of the extremely rare Habenaria dentata and the rare Habenaria linearifolia (Orchidaceae) in South Korea: implications for population history and conservation

2018 ◽  
Vol 151 (1) ◽  
pp. 48-60
Author(s):  
Mi Yoon Chung ◽  
Hoa Thi Quynh Le ◽  
Sungwon Son ◽  
Huai Zhen Tian ◽  
Myong Gi Chung
Keyword(s):  
Genetic Diversity ◽  
Southern China ◽  
Geographic Location ◽  
Population History ◽  
Population Variation ◽  
Conservation Strategies ◽  
Ancestral Population ◽  
Allozyme Diversity ◽  
Glacial Origin

Background and aims – Since historical events often leave an indelible mark on levels of genetic diversity of plant populations, one may indirectly infer their evolutionary history with the help of current patterns of genetic diversity. The terrestrial orchid Habenaria dentata, an element of warm-temperate/subtropical vegetation, reaches its northernmost limits in the Korean Peninsula, and thus it is extremely rare there. As H. dentata was absent from the Peninsula during the Last Glacial Maximum (LGM), it is likely to be of post-glacial origin having arrived from either a single refugium or multiple refugia. However, its rare, temperate/boreal congener H. linearifolia might have persisted in situ in either macrorefugia or microrefugia on the Peninsula during the LGM.Methods – To test which hypothesis is most appropriate for each species, we investigated levels of allozyme-based (17 loci) genetic diversity and population genetic structure in the two only known populations of H. dentata and in 12 populations of H. linearifolia.Key results – No allozyme diversity was found in H. dentata (He = 0.000), whereas H. linearifolia exhibited low within-population variation (He = 0.060) and high among-population differentiation (FST = 0.237). We found little association between populations in relation to their geographic location; several populations presented individuals belonging to different clusters.Conclusions – Our results suggest that H. dentata likely originated from a single ancestral population (perhaps from southern Japan or southern China) through post-glacial dispersal, whereas H. linearifolia probably survived the LGM in situ in microrefugia situated at low to mid-elevated regions. We further suggest that separate conservation strategies for each species should be employed, given that the two taxa have different ecological and demographic traits and harbour different levels of genetic diversity.

Dinucleotide microsatellites from Eucalyptus sieberi: inheritance, diversity, and improved scoring of single-base differences

Genome ◽  
2001 ◽  
Vol 44 (6) ◽  
pp. 1041-1045 ◽  
Author(s):  
J C Glaubitz ◽  
L C Emebiri ◽  
G F Moran
Keyword(s):  
Base Pair ◽  
Mendelian Inheritance ◽  
Null Alleles ◽  
Fixation Index ◽  
Eucalyptus Nitens ◽  
Internal Reference ◽  
Single Base ◽  
Hardy Weinberg Equilibrium ◽  
Single Base Pair ◽  
Flanking Regions

Eight dinucleotide microsatellites were developed in Eucalyptus sieberi L. Johnson (silvertop ash), a member of the subgenus Eucalyptus. Transfer of six of these to the subgenus Symphyomyrtus and their Mendelian inheritance are demonstrated using a full-sib cross in Eucalyptus nitens. Genetic diversity parameters are presented for the eight loci based on a sample of 100 old-growth E. sieberi trees from a single natural stand. One locus, Es266, had an atypically high fixation index, and significantly deviated from Hardy-Weinberg equilibrium genotypic proportions, indicating the likely presence of null alleles. Two of the loci, Es076 and Es140, had many alleles that differed in size by only a single base pair, possibly because of short poly(A) or poly(T) stretches in their flanking regions. These two loci were by far the most polymorphic, but were difficult to score reliably on a capillary DNA sequencer. Reliability of scoring of these two one-base microsatellite loci was markedly improved by the incorporation of internal reference alleles into each sample analysed.Key words: SSRs, single base pair alleles, null alleles, internal reference alleles.

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