scholarly journals Population Genetics of Echium plantagineum L.Target Weed for Biological Control

1986 ◽  
Vol 39 (4) ◽  
pp. 369 ◽  
Author(s):  
JJ Burdon ◽  
AHD Brown
Keyword(s):  
Genetic Diversity ◽  
Biological Control ◽  
Gene Diversity ◽  
Breeding Systems ◽  
Isozyme Loci ◽  
Source Populations ◽  
High Level ◽  
Similar Stage ◽  
Isozyme Diversity ◽  
European Populations

Eight Australian and two European populations of E. plantagineum were surveyed for their genetic structure at 16 variable isozyme loci. On average, the Australian and European populations possessed 2�7 and 2�6 alleles per locus, a gene diversity of 34 and 35% and heterozygosity of 32 and 29% respectively. Estimates of the outcrossing rate in one Australian population were 61 and 73% for mean single-locus and multi-locus methods respectively. The levels of genetic diversity detected in this species consistently exceed those detected in a range of other species that occupy a similar stage in succession or that have similar breeding systems. Moreover, contrary to expectation, genetic diversity was equally great in the colonial populations in Australia as in European-source populations. If this high level of isozyme diversity reflects the diversity likely to be found in other parts of the genome, attempts to achieve substantial biological control may require the use of many different control agents.

scholarly journals Molecular diversity and phylogeny of Triticum-Aegilops species possessing D genome revealed by SSR and ISSR markers

2015 ◽  
Vol 71 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Hoda Moradkhani ◽  
Ali Ashraf Mehrabi ◽  
Alireza Etminan ◽  
Alireza Pour-Aboughadareh
Keyword(s):  
Genetic Diversity ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
Issr Markers ◽  
Issr Marker ◽  
D Genome ◽  
Ploidy Levels ◽  
Marker Data ◽  
Geographical Regions ◽  
High Level

AbstractThe aim of this study is investigation the applicability of SSR and ISSR markers in evaluating the genetic relationships in twenty accessions ofAegilopsandTriticumspecies with D genome in different ploidy levels. Totally, 119 bands and 46 alleles were detected using ten primers for ISSR and SSR markers, respectively. Polymorphism Information Content values for all primers ranged from 0.345 to 0.375 with an average of 0.367 for SSR, and varied from 0.29 to 0.44 with the average 0.37 for ISSR marker. Analysis of molecular variance (AMOVA) revealed that 81% (ISSR) and 84% (SSR) of variability was partitioned among individuals within populations. Comparing the genetic diversity ofAegilopsandTriticumaccessions, based on genetic parameters, shows that genetic variation ofAe. crassaandAe. tauschiispecies are higher than other species, especially in terms of Nei’s gene diversity. Cluster analysis, based on both markers, separated total accessions in three groups. However, classification based on SSR marker data was not conformed to classification according to ISSR marker data. Principal co-ordinate analysis (PCoA) for SSR and ISSR data showed that, the first two components clarified 53.48% and 49.91% of the total variation, respectively. This analysis (PCoA), also, indicated consistent patterns of genetic relationships for ISSR data sets, however, the grouping of accessions was not completely accorded to their own geographical origins. Consequently, a high level of genetic diversity was revealed from the accessions sampled from different eco-geographical regions of Iran.

scholarly journals Genetic Diversity and Population Structure of Endangered Catfish Rita rita (Hamilton, 1822) Revealed by Heterologous DNA Microsatellite Markers

2021 ◽  
Vol 34 (2) ◽  
Author(s):  
MUHAMMAD FORHAD ALI ◽  
◽  
MD. RAFIQUL ISLAM SARDER ◽  
MOHAMMAD MATIUR RAHMAN ◽  
MD. FAZLUL AWAL MOLLAH ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Diversity ◽  
Polymorphic Information Content ◽  
Genetic Difference ◽  
Information Index ◽  
Hardy Weinberg Equilibrium ◽  
High Gene ◽  
High Level ◽  
Dna Microsatellite

Genetic information is essential for conservation and future aquaculture development of the endangered catfish Rita rita (Hamilton, 1822). Two hundred catfish, R. rita, 50 from four rivers, the Old Brahmaputra, Jamuna, Meghna and Kangsa were collected and analysed to evaluate the genetic diversity and population structure using five microsatellite primers (Cba06-KUL, Cba08-KUL, Cba09-KUL, Phy03-KUL and Phy07-KUL). Four of the five amplified loci were found polymorphic (P95) in all the populations and 46 alleles were recorded with 9 to 14 alleles per locus. Differences were observed in the total number of alleles ranging from 41 to 44, effective number of alleles from 29.96 to 37.46, observed heterozygosity from 0.57 to 0.76, Shannon’s information index from 2.09 to 2.30 and polymorphic information content from 0.84 to 0.88 among the four populations. Results exposed the highest levels of genetic diversity in the Meghna population while the lowest in the Kangsa population of R. rita. All the populations were significantly deviated (P < 0.001) from the Hardy-Weinberg equilibrium for all the loci. Nei’s genetic distance between populations ranged 0.007 to 0.017 with low overall genetic difference FST = 0.011 and high gene flow Nm = 24.333, indicating that R. rita populations were not subdivided. This study revealed a high level of gene diversity with deficiency in genetic heterogeneity in all the populations of R. rita, emphasising natural management, conservation and rehabilitation measures of this species.

scholarly journals Multilocus Diversity in an Outbreeding Weed, Echium piantagineum L.

1983 ◽  
Vol 36 (6) ◽  
pp. 503 ◽  
Author(s):  
AHD Brown ◽  
JJ Burdon
Keyword(s):  
Biological Control ◽  
Linkage Disequilibrium ◽  
Genetic Structure ◽  
Population Size ◽  
Gene Diversity ◽  
Genotypic Variation ◽  
Vast Array ◽  
Multilocus Genotypes ◽  
Isozyme Loci

A population of E. plantagineum was surveyed for its genetic structure at 23 isozyme loci. More than half (13) of these loci were polymorphic, with an average number of three alleles per locus, a gene diversity of 38% and heterozygosity of 35%. More importantly, the distribution of multilocus heterozygosity over individuals was found to approximate that assuming independence among loci or no linkage disequilibrium. The population consisted of a vast array of multilocus genotypes. This pattern indicates that the outbreeding system encourages recombination sufficient to outweigh the effects on multilocus structure of bottlenecks in population size. Genic and genotypic variation presumably allows high levels of biochemical flexibility in populations of E. plantagineum. Such flexibility could hamper attempts at biological control.

scholarly journals Evolution during seed production for ecological restoration? A molecular analysis of 19 species finds only minor genomic changes

2021 ◽  
Author(s):  
Malte Conrady ◽  
Christian Lampei ◽  
Oliver Bossdorf ◽  
Walter Durka ◽  
Anna Bucharova
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Ecological Restoration ◽  
Seed Production ◽  
Large Scale ◽  
Gene Diversity ◽  
Natural Populations ◽  
Genetic Change ◽  
Breeding Systems ◽  
Wild Plants

A growing number of restoration projects require large amounts of seeds. As harvesting natural populations cannot cover the demand, wild plants are often propagated in large-scale monocultures. There are concerns that this cultivation process may cause genetic drift and unintended selection, which would alter the genetic properties of the cultivated populations and reduce their genetic diversity. Such changes could reduce the pre-existing adaptation of restored populations, and limit their adaptability to environmental change. We used single nucleotide polymorphism (SNP) markers and a pool-sequencing approach to test for genetic differentiation and changes in gene diversity during cultivation in 19 wild grassland species, comparing the source populations and up to four consecutive cultivation generations grown from these sources. We then linked the magnitudes of genetic changes to the species breeding systems and seed dormancy, to understand the roles of these traits in genetic change. The propagation of native seeds for ecosystem restoration changed the genetic composition of the cultivated generations only moderately. The genetic differentiation we observed as a consequence of cultivation was much lower than the natural genetic differentiation between different source regions, and the propagated generations harbored even higher gene diversity than wild-collected seeds. Genetic change was stronger in self-compatible species, probably as a result of increased outcrossing in the monocultures. Synthesis and applications: Our study indicates that large-scale seed production maintains the genetic integrity of natural populations. Increased genetic diversity may even increase the adaptive potential of propagated seeds, which makes them especially suitable for ecological restoration. However, we have been working with seeds from Germany and Austria, where the seed production is regulated and certified. Whether other seed production systems perform equally well remains to be tested.

Genetic diversity in natural populations of Acacia mearnsii

2000 ◽  
Vol 48 (2) ◽  
pp. 279 ◽  
Author(s):  
S. D. Searle ◽  
J. C. Bell ◽  
G. F. Moran
Keyword(s):  
Genetic Diversity ◽  
Gene Diversity ◽  
New South ◽  
Natural Populations ◽  
South Australia ◽  
Population Diversity ◽  
Regional Level ◽  
Acacia Mearnsii ◽  
South Wales ◽  
Isozyme Loci

Twenty-three isozyme loci were used to examine genetic diversity within and between 19 natural populations of Acacia mearnsii De Wild. selected to represent its entire geographic range. Acacia mearnsii was found to have moderate genetic diversity (species level gene diversity HT = 0.201) with the majority (89.2%) of variation occurring within populations. All measures of population diversity were higher in the northern (New South Wales) than the southern (Victoria, South Australia, Tasmania) populations. There was some evidence of differentiation between populations but no strong clustering at a regional level.

scholarly journals Forest decline has not reduced genetic diversity of naturally regenerated Norway spruce from the Beskids, Poland

2015 ◽  
Vol 64 (1-6) ◽  
pp. 270-278 ◽  
Author(s):  
Elżbieta Chomicz-Zegar ◽  
J. A. Nowakowska ◽  
A. Tereba
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Norway Spruce ◽  
Forest Decline ◽  
Gene Diversity ◽  
Young Generation ◽  
Primeval Forest ◽  
Initial Stage ◽  
Spruce Stands ◽  
High Level

AbstractNorway spruce forests decline in the Beskids raises concerns about reduction of genetic variation in a next generation of forest. We aim to determine whether the genetic diversity in declining spruce stands was successfully transmitted to its self-seeded progeny. Using three nuclear microsatellite markers, we carried out the genetic assessment of naturally regenerated progeny and compered them with their maternal stands at an initial stage of decline. We investigated three spruce stands from the Śląski and Żywiecki Beskid and one primeval forest from the Tatras, as a reference. We noticed a high level of gene diversity, allelic richness and an effective number of alleles in progeny of all stands, without differences between declining stands from the Beskids and the primeval forest. The gene diversity was similar in maternal trees and their offspring. Higher gene diversity and generally higher number of alleles were noticed in young generation of stands. Genetic identity between generations was high in analyzed seed stands and the highest in the primeval forest. The results we presented indicate no significant effect of drastic reduction in the population size due to the forest decline on the level of genetic variation in self-seeded progeny of Norway spruce from the Beskids.

Genetic variation in lowland sorghum (Sorghum bicolor (L.) Moench) landraces assessed by simple sequence repeats

2014 ◽  
Vol 13 (2) ◽  
pp. 131-141 ◽  
Author(s):  
Beyene Amelework ◽  
Hussien Shimelis ◽  
Pangirayi Tongoona ◽  
Mark Laing ◽  
Fentahun Mengistu
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Gene Diversity ◽  
Polymorphic Information Content ◽  
Mean Value ◽  
Target Area ◽  
Eastern Ethiopia ◽  
Important Indicator ◽  
High Level ◽  
Analytical Approaches

The regions of north-eastern Ethiopia are known for their high levels of sorghum genetic diversity, and for being drought prone. For centuries, sorghum has been developed and maintained by farmers for its adaptation to the marginal and heterogeneous environment of these regions. The objective of this study was to examine the genetic diversity and population structure of 200 sorghum landraces collected from seven lowland districts, using 30 microsatellite markers sampled from all linkage groups of the sorghum genome. Both distance-based and model-based analytical approaches were used to analyse the data. The data analysis revealed that there was a large variation among all the markers under study. The values of polymorphic information content ranged from 0.26 to 0.88, with a mean value of 0.61, reflecting the high discriminating ability of the markers studied. The mean value of total gene diversity was 0.69, which partitioned 86% among the landraces and 14% within the landraces. Gene diversity among the landraces was largely due to the variation among the genotypes within the geographic origins. Landraces sampled from different collection sites appeared to cluster together, indicating the existence of a high level of gene flow among the sites of collection. This indicates that a relatively small, random collection of landraces would capture the bulk of genetic diversity in the target area. A moderately high level of genetic differentiation and a relatively low level of gene flow were observed between sorghum races and maturity groups. Given that the target area is marginal, drought prone and heterogeneous, the study of genetic diversity among sorghum landraces could serve as an important indicator of valuable alleles for drought tolerance in future sorghum improvement programmes.

Assessment of Genetic Diversity in Ethiopian Sesame (Sesamum indicum L.) Germplasm using Random Amplified Polymorphic DNA (RAPD) Markers

2015 ◽  
Vol 5 (2) ◽  
pp. 639-649
Author(s):  
Mohammed Abate Dawud ◽  
Firew Mekbib Alemu
Keyword(s):  
Genetic Diversity ◽  
Rapd Markers ◽  
Gene Diversity ◽  
Random Amplified Polymorphic Dna ◽  
Sesamum Indicum ◽  
Dissimilarity Matrix ◽  
Information Index ◽  
Sesame Genotypes ◽  
High Level ◽  
Maximum Similarity

Genetic diversity among 128 sesame (Sesamum indicum L.) genotypes representing 10 geographically distinct populations in Ethiopia was assessed at DNA level using RAPD analysis. Eleven RAPD primers used amplified a total of 149 bands, of which 142 (95. 45%) were polymorphic. Each primer generated 7 to 23 amplified fragments with an average of 13.5 bands per primer. Percent of polymorphic loci (P%), number of different (Na) and effective (Ne) alleles along with Shannon information index (I) and Nei’s gene diversity (He) values suggested that the population of Oromia was the most diverse of all populations, while populations from Afar (cultivars) and AM-NSh were found to be the least diverse. Based on average dissimilarity values obtained with RAPD primers, AM-NG-25, SNNP-7 and SNNP-8 were the most distinct of all genotypes, while genotypes ORO-20 and TIGR-5 showed maximum similarity with others. The UPGMA clustering based on the dissimilarity matrix clustered the genotypes into 3 major groups and 11 subgroups, while three genotypes viz., BENSH-6, ORO-14 and SNNP-5 were found out-grouped from the rest and did not join any of the cluster; they are then most divergent genotypes. Generally, both clustering and PCoA patterns revealed that most genotypes located geographically far apart were found to cluster in the same group, while those genotypes from the same origin dispersed. Overall results indicated that RAPD technique revealed a high level of genetic variation among sesame genotypes collected from diverse ecologies of Ethiopia. 

scholarly journals Eficiența unor marcheri moleculari în discriminarea populațiilor de lupoaie originare din China

2021 ◽  
Author(s):  
Maria Duca ◽  
◽  
Ana Mutu ◽  
Ina Bivol ◽  
Steliana Clapco ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Gene Diversity ◽  
Issr Markers ◽  
Resolving Power ◽  
Information Index ◽  
Combined Use ◽  
Different Types ◽  
High Level ◽  
Different Levels

In this study, the effectiveness of different types of molecular markers in assessing genetic diversity of populations of O. cumana from China was determined. ISSR and SSR markers detected different levels of genetic variability among and within broomrape populations. SSR markers analysis showed high level of genetic variation within the populations as revealed by high average values of Nei's gene diversity (H=0,75) and Shannon's information index (I=1,44), while genotyping with ISSR markers showed greater ability to discriminate genotypes according to Resolving power (Rp=7,24). Thus, the combined use of ISSR and SSR markers allowed the detection of higher polymorphism than either set of marker alone.

scholarly journals Research Genetic diversity of Ottelia acuminata (Hydrocharitaceae) from the Eastern Himalayas, revealed by ISSR markers

1970 ◽  
Vol 7 ◽  
pp. 56-63 ◽  
Author(s):  
Chunlin Long ◽  
Zhutan Jiang ◽  
Zhiling Dao
Keyword(s):  
Genetic Diversity ◽  
Gene Diversity ◽  
Natural Populations ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Ex Situ ◽  
Eastern Himalayas ◽  
Average Value ◽  
Geographical Distances ◽  
High Level

Ottelia acuminata (Gagnep.) Dandy (Hydrocharitaceae), an endangered aquatic species, was investigated in the Eastern Himalayas, especially in Yunnan Province of Southwest China. The genetic diversity among seven populations was examined using inter-simple sequence repeat (ISSR) amplification markers. The field survey showed that 43.5% natural populations of O. acuminata have become extinct during the last 30 years. Among 13 remaining wild populations, eight (61.5%) are on the edge of extinction and only five (38.5%) were unaffected. For the study on seven populations based on ten primers, 147 clear and reproducible DNA fragments were generated, of which 144 (97.96%) were polymorphic. Within populations, however, the polymorphic bands (PPB) generated by ISSRs was 53 and occupied 36.05% in population B, and similarly within population J (51 and 34.69%, respectively). The results showed that genetic variation is much higher among populations of O. acuminata than within populations. Analyses of Nei’s gene diversity, genetic distance and Shannon’s index also agreed with these results. The average value of Nei’s gene diversity (h) equaled 0.3710. The coefficient of genetic differentiation (Gst) equaled 0.5487, which means that 54.87% of the total molecular variance existed among populations. Such a high level of divergence present among populations may be caused by the complex topography and separated habitats which effectively restrict gene flow. Moreover, there is a lack of significant association between genetic and geographical distances (r = 0.28889, P > 0.05) in the populations of O. acuminata. Therefore, we proposed an appropriate strategy for conserving the genetic resources of O. acuminata in the Eastern Himalayas; namely, rescuing and conserving the core populations in situ, while selecting and preserving more populations with fewer individuals from each population ex situ. Key-words: Ottelia acuminata, genetic diversity, conservation, Eastern Himalayas, Yunnan Plateau, China DOI: 10.3126/botor.v7i0.4374Botanica Orientalis – Journal of Plant Science (2010) 7: 56-63

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