Genetic diversity in Mediterranean diploid and tetraploid Bromus L. (section Bromus Sm.) populations

Genome ◽  
1995 ◽  
Vol 38 (5) ◽  
pp. 879-888 ◽  
Author(s):  
Malika Ainouche ◽  
Marie-Thérèse Misset ◽  
André Huon
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
Genetic Variation ◽  
Genetic Similarity ◽  
Gene Diversity ◽  
Enzyme Electrophoresis ◽  
Allozyme Data ◽  
Fixed Heterozygosity ◽  
The Mean ◽  
Diploid Populations

The levels of genetic diversity assessed from allozyme data were investigated in 25 populations of Mediterranean Bromus intermedius, B. squarrosus, B. lanceolatus, and B. hordeaceus from Algeria. The geographically restricted diploids B. intermedius and B. squarrosus displayed less genetic diversity (the mean population gene diversity of Nei (Hu) ranged from 0.03 to 0.12) than the widespread tetraploid colonizers B. lanceolatus and B. hordeaceus (Hu = 0.07–0.27). Deviations from Hardy–Weinberg expectations in diploid populations of B. intermedius and B. squarrosus were observed owing to heterozygote excess at several loci and suggested that these self-fertilizing species may have substantial amounts of allogamy. Tetraploid populations of B. lanceolatus and B. hordeaceus were largely homozygous at homologous loci and frequently exhibited intergenomic fixed heterozygosity in accordance with their alloploid origin. Genetic variation at the infraspecific level was mostly distributed within populations in the four species, B. hordeaceus showing the lowest level of interpopulation differentiation (Gst = 0.06) and the highest level of gene flow (Nm = 3.75). Consistent gene flows are in agreement with the strongest intercontinental invasive behaviour of B. hordeaceus. Less differentiation was reported in the literature among later introduced B. hordeaceus populations from England and Australia, indicating reduced differentiation under the process of colonization. Moderate divergence occured among the four taxa, with interspecific genetic identities ranging from 0.87 to 0.93. In spite of substantial genetic similarity, species were clearly differentiated, with each tetraploid being more closely related to a diploid: B. hordeaceus to B. squarrosus and B. lanceolatus to B. intermedius.Key words: Bromus, enzyme electrophoresis, population genetics, colonizing abilities, allopolyploidy.

Conservation genetics and ecology of the endangered rainforest shrub, Triunia robusta, from the Sunshine Coast, Australia

2002 ◽  
Vol 50 (1) ◽  
pp. 93 ◽  
Author(s):  
Alison Shapcott
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Conservation Genetics ◽  
Population Size ◽  
Genetic Similarity ◽  
Small Region ◽  
Geographic Proximity ◽  
Close Proximity ◽  
The Mean

Triunia robusta, which until recently was thought to be extinct, is now classified nationally as endangered. It is an understorey species restricted to the subcoastal rainforests in a small region of the Sunshine Coast, Queensland. The project involved sampling the genetic variation and measuring the population size and size distribution of T. robusta and its geographically closest congener T. youngiana, which occurs further south and has a wider geographic distribution. A total of 877 T. robusta plants were recorded across the 11 populations, approximately half (56.8%) of these were juveniles less than 1 m tall, whereas in T. youngiana only about 36.4% of a population was composed of juveniles. Genetic diversity was similar but significantly higher for T. robusta than T. youngiana if the very small T. robusta populations (2 or 3 plants) were excluded from analysis (P < 0.05). The mean percentage of polymorphic loci among populations was high for both species. Triunia robusta is not, on average, more inbred than the more common T. youngiana. There was more differentiation between the T. robusta populations, which were in close proximity, than between the more geographically separated T. youngiana populations. Thus, there is evidence of more gene flow between populations of T. youngiana than between those of T. robusta. However, there was no geographic relationship between genetic similarity and geographic proximity in T. robusta

scholarly journals Genetic diversity and population structure of Eurycoma apiculata in Eastern Sumatra, Indonesia

2021 ◽  
Vol 22 (10) ◽  
Author(s):  
Zulfahmi Zulfahmi ◽  
Parjanto Parjanto ◽  
Edi Purwanto ◽  
Ahmad Yunus
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Differentiation ◽  
Gene Diversity ◽  
In Situ Conservation ◽  
Genetic Material ◽  
Ex Situ ◽  
Breeding Programs ◽  
The Mean

Abstract. Zulfahmi, Parjanto, Purwanto E, Yunus A. 2021. Genetic diversity and population structure of Eurycoma apiculata in Eastern Sumatra, Indonesia. Biodiversitas 22: 4431-4439. Information on genetic variation within and among populations of Eurycoma apiculata plants is important to develop strategies for their conservation, sustainable use, and genetic improvement. To date, no information on genetic variation within and among populations of the E. apiculata has been reported. This study aims to assess genetic diversity within and among populations of E. apiculata based on RAPD markers, and to determine populations to collect E. apiculata genetic material for conservation and breeding programs. Young leaves of E. apiculata were collected from six natural populations. Fifteen RAPD primers were used to assess the genetic diversity of each population. The data obtained were analyzed with POPGEN and Arlequin software. The amplification results of 15 selected primers produced 3-16 loci with all primers 100% polymorphic. At the species level, the mean allele per locus (Na), number of effective alleles (Ne), percentage of polymorphic loci (PPL), Nei’s gene diversity index (He) and Shannon information index (I) were 2.000, 1.244, 100%, 0.167, and 0.286, respectively. At the population level, the mean values for Na, Ne, PPL, He and I were 1.393, 1.312, 39.27%, 0.119, and 0.186, respectively. The highest value of gene diversity within population (He) was found in the Lingga-1 population and the lowest value was found in the Rumbio population. The value of genetic differentiation among populations (GST) of E. apiculata is 0.284, consistent with the results of the AMOVA analysis which found that genetic variation among populations was 23.14%, indicates that the genetic variation of E. apiculata was more stored within populations than among populations. The gene flow (Nm) value of E. apiculata was 1.259 migrants per generation among populations. The Nm value of this species was high category, and could inhibit genetic differentiation among populations. The clustering of E. apiculata population based on the UPGMA dendrogram and PCA was inconsistent with its geographic distribution, reflecting the possibility that genes migration occurred between islands in the past. The main finding of this study was the genetic variation of the E. apiculata mostly stored within the population. Therefore, the population with the highest genetic diversity is a priority for in-situ conservation, and collection of E. apiculata genetic material for ex-situ conservation and breeding programs should be carried out minimum from Lingga-1 and Pokomo populations.

scholarly journals Genetic Variation and Population Structure in Jamunapari Goats Using Microsatellites, Mitochondrial DNA, and Milk Protein Genes

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
P. K. Rout ◽  
K. Thangraj ◽  
A. Mandal ◽  
R. Roy
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
Genetic Variation ◽  
Population Size ◽  
Microsatellite Loci ◽  
Milk Protein ◽  
Gene Diversity ◽  
Population History ◽  
Dairy Goat ◽  
The Mean

Jamunapari, a dairy goat breed of India, has been gradually declining in numbers in its home tract over the years. We have analysed genetic variation and population history in Jamunapari goats based on 17 microsatellite loci, 2 milk protein loci, mitochondrial hypervariable region I (HVRI) sequencing, and three Y-chromosomal gene sequencing. We used the mitochondrial DNA (mtDNA) mismatch distribution, microsatellite data, and bottleneck tests to infer the population history and demography. The mean number of alleles per locus was 9.0 indicating that the allelic variation was high in all the loci and the mean heterozygosity was 0.769 at nuclear loci. Although the population size is smaller than 8,000 individuals, the amount of variability both in terms of allelic richness and gene diversity was high in all the microsatellite loci except ILST 005. The gene diversity and effective number of alleles at milk protein loci were higher than the 10 other Indian goat breeds that they were compared to. Mismatch analysis was carried out and the analysis revealed that the population curve was unimodal indicating the expansion of population. The genetic diversity of Y-chromosome genes was low in the present study. The observed mean M ratio in the population was above the critical significance value (Mc) and close to one indicating that it has maintained a slowly changing population size. The mode-shift test did not detect any distortion of allele frequency and the heterozygosity excess method showed that there was no significant departure from mutation-drift equilibrium detected in the population. However, the effects of genetic bottlenecks were observed in some loci due to decreased heterozygosity and lower level of M ratio. There were two observed genetic subdivisions in the population supporting the observations of farmers in different areas. This base line information on genetic diversity, bottleneck analysis, and mismatch analysis was obtained to assist the conservation decision and management of the breed.

scholarly journals Genetic diversity of Avena strigosa Schreb. ecotypes on the basis of isoenzyme markers

2009 ◽  
Vol 15 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Katarzyna Kubiak
Keyword(s):  
Genetic Diversity ◽  
Genetic Similarity ◽  
Avena Strigosa ◽  
Total Genetic Diversity ◽  
Geographical Regions ◽  
The World ◽  
Total Variability ◽  
The Mean ◽  
Intrapopulation Diversity ◽  
Very High

Genetic diversity ofAvena strigosaSchreb. ecotypes on the basis of isoenzyme markersGenetic diversity was analyzed in 19 ecotypes of the diploid oatA. strigosaoriginating from various geographical regions of the world. Six isoenzyme systems (AAT, ACP, EST, LAP, MDH, PX) were studied and 16 loci were identified. Only two loci (Est4andMdh2) were polymorphic. Ecotypes were characterized by the percentage of polymorphic loci (P=3.3%), the mean number of alleles per locus (A=1.04) and intrapopulation diversity (HS=0.013). Total genetic diversity (HT=0.07) and interpopulation diversity (DST=0.057) were examined as well. The value of the coefficient of gene differentiation (GST=0.821) indicated that diversity among populations was an important contributor to total variability. Genetic similarity betweenA. strigosapopulations was very high (IN=0.94). Cluster analysis did not demonstrate strongly differentiated groups among the ecotypes examined.

Genetic Diversity among Calamus brandisii Becc. (Arecaceae) Populations in Kerala Part of Western Ghats

2021 ◽  
Vol 43 (1) ◽  
pp. 38-42
Author(s):  
Kavungal Priya ◽  
◽  
Indira . ◽  
Vadakkethil Balakrishnan Sreekumar ◽  
Renuka . ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Western Ghats ◽  
Rapd Markers ◽  
Gene Diversity ◽  
Issr Markers ◽  
High Genetic Diversity ◽  
Western Ghats Of India ◽  
The Mean ◽  
Two Parameters ◽  
Two Populations

Calamus brandisii Becc. is one of the endemic slender rattans found in the Western Ghats of India. The genetic diversity of two main populations available in Kerala was investigated using 20 RAPD and 9 ISSR markers. Two parameters viz., gene diversity and genetic diversity within and among populations were analyzed. ISSR analysis showed quite high genetic diversity in Pandimotta compared to Bonacaud population whereas in RAPD markers both these populations were moderately diverse. The percentage of total genetic differentiation (Gst) among two populations is relatively higher than the mean Gst value indicating high genetic diversity within the populations. The genetic distance between these two populations was 0.1739 with ISSR markers and 0.1971 with RAPD markers. Because of its high genetic diversity, Pandimotta population can be treated as an important population of gene diversity with potentially useful genes. This may be included in the high priority reservoir for genetic conservation also.

scholarly journals Genetic studies revealed differences between European and North American populations of Calypogeia azurea

2016 ◽  
Vol 42 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Katarzyna Buczkowska ◽  
Alina Bączkiewicz ◽  
Patrycja Gonera
Keyword(s):  
Genetic Variation ◽  
North America ◽  
Genetic Distance ◽  
Gene Diversity ◽  
Oil Bodies ◽  
Genetic Studies ◽  
Isozyme Loci ◽  
The Mean ◽  
Different Parts ◽  
Nei's Genetic Distance

Abstract Calypogeia azurea, a widespread, subboreal-montane liverwort species, is one of a few representatives of the Calypogeia genus that are characterized by the occurrence of blue oil bodies. The aim of the study was to investigate the genetic variation and population structure of C. azurea originating from different parts of its distribution range (Europe and North America). Plants of C. azurea were compared with C. peruviana, another Calypogeia species with blue oil bodies. In general, 339 gametophytes from 15 populations of C. azurea were examined. Total gene diversity (HT) estimated on the basis of nine isozyme loci of C. azurea at the species level was 0.201. The mean Nei’s genetic distance between European populations was equal to 0.083, whereas the mean genetic distance between populations originating from Europe and North America was 0.413. The analysis of molecular variance (AMOVA) showed that 69% of C. azurea genetic variation was distributed among regions (Europe and North America), 15% - among populations within regions, and 16% - within populations. Our study revealed that C. azurea showed genetic diversity within its geographic distribution. All examined samples classified as C. azurea differed in respect of isozyme patterns from C. peruviana.

scholarly journals Genetic diversity in wild and hatchery populations of stinging catfish (Heteropneustes fossilis Bloch) revealed by RAPD analysis

2012 ◽  
Vol 19 ◽  
pp. 81-87
Author(s):  
Md Nazrul Islam ◽  
Abhishak Basak ◽  
Dr Ashrafullah ◽  
Md Samsul Alam
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Gene Diversity ◽  
Similarity Index ◽  
Heteropneustes Fossilis ◽  
Wild Populations ◽  
Polymorphic Loci

Context: DNA fingerprinting using genetic markers such as Random Amplification of Polymorphic DNA (RAPD), Restriction Fragment Length Polymorphism (RFLP), microsatellite (Simple sequence repeat), Amplified Fragment Length Polymorphism (AFLP) etc. can be successfully used to reveal genetic variation within and among different populations. Objective: The aim of the present study was to assess genetic diversity in two wild and one hatchery populations of stinging catfish Heteropneustes fossilis by RAPD fingerprinting. Materials and Methods: A total of 90 live fish (H. fossilis), 30 from each source, were collected from a beel in Patuakhali, a beel in Jessore and Rupali Hatchery, Mymensingh. Genomic DNA was extracted from fin tissues. The concentration of DNA was estimated using a spectrophotometer. Fifteen decamer primers of random sequence from three kits (six from kit A, seven from kit B and two from kit C) (Operon technologies, Inc., Alameda, CA, USA) were screened on sub-samples of one randomly chosen H. fossilis DNA sample from the each population to test their suitability for amplifying RAPDs. The amplified products from each sample were separated by electrophoresis on 1.4% agarose gel containing ethidium bromide. The sizes of the bands were calculated using the software DNAFRAG and the sizes in base pair (bp) were used for identification of the bands (RAPD markers). The similarity index values (SI) between the RAPD fingerprint of any two individuals on the same gel were calculated from RAPD band sharing. Results: A total of 28 RAPD bands were obtained using four decamer random primers, among which 21 bands were polymorphic. The percentage of polymorphic loci, intra-population similarity indices and Nei's gene diversity values were 85.71%, 78.75 and 0.304±0.183 for Jessore population, 83.71%, 82.62 and 0.280±0.159 for Patuakhali population, 82.14%, 85.25 and 0.271±0.165 for Rupali hatchery population, respectively. The overall gene flow (Nm) among the populations was 5.755. The highest inter-similarity (Sij) was found between Patuakhali - Rupali hatchery populations. Among the three populations, the highest genetic distance (0.069) was found between Jessore and Patuakhali population. Considering polymorphic loci, intrapopulation similarity index and gene diversity the genetic variation in the Jessore population was higher than the other two populations. The genetic variation of the hatchery population was found to be lower than the two wild populations. Conclusion: The result of the present study can be used as baseline information regarding the genetic variation and population structure before undertaking any breeding programme. Study indicated that the genetic variation in the hatchery populations were slightly lower than those of the wild populations. DOI: http://dx.doi.org/10.3329/jbs.v19i0.13005 J. bio-sci. 19 81-87, 2011

Genetic diversity of high-molecular-weight glutenin subunit compositions in bread wheat landraces originated from Turkey

2016 ◽  
Vol 16 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Ridvan Temizgul ◽  
Mikail Akbulut ◽  
Domenico Lafiandra
Keyword(s):  
Genetic Diversity ◽  
Molecular Weight ◽  
Genetic Variation ◽  
High Molecular Weight ◽  
Bread Wheat ◽  
Gene Diversity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Genetic Erosion ◽  
Allele Polymorphism ◽  
Wheat Landraces

AbstractFocusing on 116 bread wheat landraces, this study investigated high molecular weight glutenin allele polymorphism, gene diversity, genetic variation and linkage disequilibrium (LD) inGlu-1loci. To identify gluten alleles, sodium dodesyl sulphate-polyacrylamide, gel electrophoresis was used and for statistical analyses POPGENE software was employed. The results indicated that average genetic variation (h) was the highest inGlu-B1(0.6421) and the lowest inGlu-A1locus (0.4548); genetic similarity ratio (I) was the highest inGlu-B1(1.4170); the highest average genetic diversity (Ht) was observed inGlu-B1(0.6575) and the lowest diversity was observed inGlu-A1(0.4558). It was also observed that genetic diversity inGlu-1locus was largely due to intra-population variations. Inter-population gene flow was also calculated as 4.0051. Marmara and Southeastern Anatolia regions, the results further indicated, had the highest (2.8691) and lowest (0.1694) heterozygosity. Genetic erosion risk for Turkish bread wheat landraces was also seen to be high. Considering the mutual analyses of subunits of nationwide wheat landraces, it is possible to speculate about a limited migration between the landraces. LD of the landraces was largely because of this limited migration and/or epistatic natural selection. Since Turkey is known as the gene centre for major cereals including wheat, barley, rye and oat, where they diversified and spread throughout the world, studying the gluten allele diversity of Turkish bread wheat landraces is important. In addition, this study has revealed the applicability of LD, and neutrality tests to gluten protein diversity for the first time.

Genetic Variation in Invasive Populations of Yellow Toadflax (Linaria vulgaris) in the Western United States

Weed Science ◽  
2008 ◽  
Vol 56 (3) ◽  
pp. 394-399 ◽  
Author(s):  
Sarah M. Ward ◽  
Scott D. Reid ◽  
Judy Harrington ◽  
Jason Sutton ◽  
K George Beck
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Recombination ◽  
Diversity Index ◽  
Gene Diversity ◽  
Group Method ◽  
Restricted Gene Flow ◽  
Genetic Structuring ◽  
Invasive Weed ◽  
Yellow Toadflax

Intraspecific genetic variation may contribute significantly to invasiveness and control problems, but has been characterized to date in relatively few invasive weed species. We examined 56 intersimple sequence repeat (ISSR) loci in 220 individuals from 11 invading populations of yellow toadflax sampled across five western states. All populations showed high levels of genetic diversity. Estimated values for Shannon's diversity measure ranged from 0.217 to 0.388, and for expected heterozygosity from 0.178 to 0.260. Nei's total gene diversity index (HT), on the basis of all individuals across all populations, was 0.267. Partitioning of genetic variance using analysis of molecular variance revealed 1.7% of genetic variation among regional population groups, 29.1% among populations within groups, and 69.2% within populations, consistent with expectations for an outcrossing species but suggesting little geographic differentiation. Pairs of adjacent individuals identical at all ISSR loci that appeared to be ramets of a single clone were detected in only one population. This indicates that patch expansion in yellow toadflax is driven more by sexual reproduction via seed than by rhizomatous clonal spread, at least at the spatial scale of sampling for this study. Eight populations had significant values for Mantel's R at P = 0.05, suggesting some fine-scale positive genetic structuring, possibly from restricted gene flow. Population clustering on the basis of Nei's genetic distance between populations and unweighted pair group method with arithmetic mean did not reflect geographic location. It is likely that multiple introductions of this species have occurred across the Intermountain West, followed by extensive genetic recombination. High levels of genetic diversity within yellow toadflax populations pose management challenges, as already seen in reports of variable response to herbicide application and limited impacts of biocontrol agent releases.

Genetic variation in the greater bilby (Macrotis lagotis)

1994 ◽  
Vol 1 (1) ◽  
pp. 46 ◽  
Author(s):  
Richard Southgate ◽  
Mark Adams
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Variability ◽  
Population Genetic ◽  
Taxonomic Status ◽  
Biological Species ◽  
Significant Loss ◽  
Allozyme Electrophoresis ◽  
Allozyme Data ◽  
Data Support

The taxonomic status of and genetic diversity amongst extant populations of the greater bilby, Macrotis lagotis, were assessed using allozyme electrophoresis. A total of 47 bilbies sampled from three geographic areas and two captive colonies were screened for 42 loci, six of which were polymorphic. The results are consistent with the view that all extant populations represent a single biological species. All populations were genetically very similar (Nei D's 0.000 to 0.004) and overall levels of within-population genetic variability were low (Ho 0.004 � 0.004 to 0.0026 � 0.017). The allozyme data support the hypothesis that there has been no significant loss of variability in the captive colonies when compared to the species as a whole.

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