Populations of sugarcane aphid and corn leaf aphid infestingSorghum bicolorandS. halepensein Kansas show low levels of genetic diversity

2016 ◽  
Author(s):  
Alicia E Timm
Keyword(s):  
Genetic Diversity ◽  
Sugarcane Aphid ◽  
Corn Leaf Aphid ◽  
Low Levels

scholarly journals Genetic diversity of rice stem borer (Chilo suppressalis Walker) from Northern Iran and comparison with other countries

2016 ◽  
Vol 48 (3) ◽  
pp. 360 ◽  
Author(s):  
M. Shayanmehr ◽  
E. Yoosefi-Lafooraki
Keyword(s):  
Genetic Diversity ◽  
Stem Borer ◽  
Chilo Suppressalis ◽  
Mazandaran Province ◽  
Northern Iran ◽  
Low Genetic Diversity ◽  
High Gene ◽  
Major Pest ◽  
Different Populations ◽  
Low Levels

Rice striped stem borer, <em>Chilo suppressalis</em> Walker (Lepidoptera: Crambidae) is considered the major pest of rice in Iran. Because of the serious damage on rice in Northern Iran, the present study was conducted to investigate genetic diversity within populations of <em>C. suppressalis</em>, from Mazandaran using a template of cytochrome oxidase I gene, 750 bps, (<em>COI</em>). Later the haplotypes from Iran were compared with those found in other countries. According to the results of this study, there is very low genetic diversity (two haplotypes) among different populations of this pest in populations of Northern Iran. The genetic similarity and low levels of genetic diversity of these populations suggest that the pest colonization occurred relatively recently and there is high gene flow between these populations of the province. In addition, haplotypes of Mazandaran province are different with those found in other countries. The similarity of Iranian population (Simorgh) with one population from China indicated that China might be the origin of <em>C. suppresalis</em>.

scholarly journals Population genetic structure and variability in Lindera glauca (Lauraceae) indicates low levels of genetic diversity and skewed sex ratios in natural populations in mainland China

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8304 ◽  
Author(s):  
Biao Xiong ◽  
Limei Zhang ◽  
Shubin Dong ◽  
Zhixiang Zhang
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Isolation By Distance ◽  
Sex Ratios ◽  
Mainland China ◽  
Small Sample ◽  
Chloroplast Microsatellites ◽  
Wild Populations ◽  
Haplotype Networks ◽  
Low Levels

Lindera glauca (Lauraceae) is a tree of economic and ecological significance that reproduces sexually and asexually via apomictic seeds. It is widely distributed in the low-altitude montane forests of East Asia. Despite the potential implications of a mixed reproductive system in terms of genetic diversity, few studies have focused on this aspect. In this study, the genetic structure of wild populations of L. glauca was investigated via genetic analyses. Overall, 13 nuclear microsatellites (nSSRs) and five chloroplast microsatellites (cpSSRs) were used to genotype 300 individual plants, taken from 20 wild populations (a small sample size in some wild populations is due to the limitation of its specific reproduction, leading to certain limitations in the results of this study) and two cultivated populations ranging across nearly the entire natural distribution of mainland China. The populations exhibited low levels of genetic diversity (nSSR: AR = 1.75, Ho = 0.32, He = 0.36; cpSSR: Nb = 2.01, Hrs = 0.40), and no significant effect of isolation by distance between populations existed, regardless of marker type (nSSR: R2 = 0.0401, P = 0.068; cpSSR: R2 = 0.033, P = 0.091). Haplotype networks showed complex relationships among populations, and the H12 haplotype was predominant in most populations. Analyses of molecular variance obtained with nuclear markers (Fsc = 0.293, FST = 0.362) and chloroplast markers (Fsc = 0.299, FST = 0.312) were similar. The migration ratio of pollen flow versus seed flow in this study was negative (r = −1.149). Results suggest that weak barriers of dispersal between populations and/or the similarity of founders shared between neighbors and distant populations are indicative of the gene flow between populations more likely involving seeds. Wild L. glauca in mainland China was inferred to have highly skewed sex ratios with predominant females. In addition, some populations experienced a recent bottleneck effect, especially in Gujianshan, Chongqing, and southwest China (population GJS). It is suggested that few wild male individuals should be conserved in order to maintain overall genetic diversity in the wild populations of this species. These findings provide important information for the sustainable utilization and preservation of the overall genetic diversity of L. glauca.

scholarly journals Evolution of recombination in eutherian mammals: insights into mechanisms that affect recombination rates and crossover interference

2013 ◽  
Vol 280 (1771) ◽  
pp. 20131945 ◽  
Author(s):  
Joana Segura ◽  
Luca Ferretti ◽  
Sebastián Ramos-Onsins ◽  
Laia Capilla ◽  
Marta Farré ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mammalian Species ◽  
Evolutionary Change ◽  
Critical Importance ◽  
Recombination Rates ◽  
Allelic Variants ◽  
Crossover Interference ◽  
Chromosomal Segregation ◽  
Low Levels ◽  
Taxonomic Groups

Recombination allows faithful chromosomal segregation during meiosis and contributes to the production of new heritable allelic variants that are essential for the maintenance of genetic diversity. Therefore, an appreciation of how this variation is created and maintained is of critical importance to our understanding of biodiversity and evolutionary change. Here, we analysed the recombination features from species representing the major eutherian taxonomic groups Afrotheria, Rodentia, Primates and Carnivora to better understand the dynamics of mammalian recombination. Our results suggest a phylogenetic component in recombination rates (RRs), which appears to be directional, strongly punctuated and subject to selection. Species that diversified earlier in the evolutionary tree have lower RRs than those from more derived phylogenetic branches. Furthermore, chromosome-specific recombination maps in distantly related taxa show that crossover interference is especially weak in the species with highest RRs detected thus far, the tiger. This is the first example of a mammalian species exhibiting such low levels of crossover interference, highlighting the uniqueness of this species and its relevance for the study of the mechanisms controlling crossover formation, distribution and resolution.

scholarly journals Genetic diversity in different populations of sloths assessed by DNA fingerprinting

2002 ◽  
Vol 62 (3) ◽  
pp. 503-508 ◽  
Author(s):  
N. MORAES ◽  
J. S. MORGANTE ◽  
C. Y. MIYAKI
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Dna Fingerprinting ◽  
Genetic Similarity ◽  
Similarity Indices ◽  
Different Populations ◽  
Related Individuals ◽  
Low Levels ◽  
Dna Profiles ◽  
Two Populations

In this study we analyzed a population of Bradypus torquatus with individuals originally distributed in different localities of Bahia, and two populations of B. variegatus with individuals from Bahia and São Paulo States. Using the DNA fingerprinting method, we assessed the genetic variability within and between populations. Analysis of the DNA profiles revealed genetic similarity indices ranging from 0.34 ± 0.07 to 0.87 ± 0.04. Similar low levels of genetic variability were found only in isolated mammalian populations or among related individuals. This study presents the first analyses of genetic diversity in sloth populations.

Genetic diversity of three Aegla species (Decapoda, Anomura) revealed by AFLP and mtDNA markers

Crustaceana ◽  
2019 ◽  
Vol 92 (4) ◽  
pp. 445-462
Author(s):  
Bianca L. Zimmermann ◽  
Jober V. De Vargas Machado ◽  
Sandro Santos ◽  
Marlise L. Bartholomei-Santos
Keyword(s):  
Genetic Diversity ◽  
Distinct Species ◽  
Genetic Distances ◽  
Species Level ◽  
Taxonomic Resolution ◽  
Similar Species ◽  
Southern Brazil ◽  
Low Levels ◽  
Management And Conservation ◽  
Mtdna Markers

Abstract Representatives of the genus Aegla present a conserved morphology; thus, the increased use of molecular markers has raised many taxonomic issues. We used AFLP and mtDNA to investigate the genetic differentiation and phylogenetic relationships of morphologically similar species with overlapping distribution areas in southern Brazil: A. georginae, A. ludwigi, and A. platensis. While A. platensis is widely distributed, the critically endangered A. georginae and A. ludwigi have limited distributions. Although both markers showed populations with low levels of genetic variability, they differed markedly in revealing relationships between populations; according to AFLP, the genetic distances between A. platensis populations were as high as those between distinct species, a result not observed when considering mtDNA data. We emphasize that the use of multiple lines of evidence is necessary for defining correct levels of genetic diversity and a good species-level taxonomic resolution. Such features are essential for the management and conservation of Aegla species.

Conservation genetics of Pitcher’s thistle (Cirsium pitcheri), an endangered Great Lakes endemic

Botany ◽  
2010 ◽  
Vol 88 (3) ◽  
pp. 250-257 ◽  
Author(s):  
Martha Gauthier ◽  
Emily Crowe ◽  
Lindsey Hawke ◽  
Neil Emery ◽  
Paul Wilson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Great Lakes ◽  
Genetic Data ◽  
Nuclear Data ◽  
Population Connectivity ◽  
Chloroplast Microsatellite ◽  
Management Plans ◽  
Low Levels ◽  
Cirsium Pitcheri ◽  
Pitcher's Thistle

Pitcher's thistle ( Cirsium pitcheri Torr. ex Eaton (Torr. & Gray)) is a Great Lakes endemic that in Canada is designated as threatened at both the provincial (Ontario) and national levels. Management plans will benefit from conservation genetic data, which can provide insight into population genetic diversity and differentiation. We obtained genetic data from nuclear and chloroplast microsatellite markers from 17 populations of C. pitcheri around the Great Lakes. The nuclear data revealed overall low levels of diversity, high levels of inbreeding, and low levels of population connectivity. The chloroplast data identified a single haplotype, which is consistent with reduced genetic diversity following postglacial colonization. The high levels of inbreeding within populations will likely pose a serious threat to populations in the short term; these have resulted from a combination of low connectivity between populations, and small and fluctuating population sizes. Future management of C. pitcheri populations should consider human-mediated dispersal of plants or seeds among sites.

Regional divergence and inbreeding in Eucalyptus cladocalyx (Myrtaceae)

2003 ◽  
Vol 51 (4) ◽  
pp. 393 ◽  
Author(s):  
M. W. McDonald ◽  
M. Rawlings ◽  
P. A. Butcher ◽  
J. C. Bell
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
South Australia ◽  
Natural Distribution ◽  
Flinders Ranges ◽  
Outcrossing Rates ◽  
Low Levels ◽  
Western Victoria ◽  
Ornamental Species ◽  
Regional Divergence

Eucalyptus cladocalyx F.Muell. is a widely cultivated tree in dryland southern Australia. It is grown for firewood, timber production and as a windbreak and ornamental species. Natural populations of E. cladocalyx are endemic to South Australia where they occur in three disjunct regions. This study assessed the mating system and patterns of genetic diversity in natural populations of E. cladocalyx by using allozymes. Populations had relatively low levels of genetic diversity (HE = 0.148) and high levels of genetic divergence (θ = 0.26) among populations, similar to other regionally distributed eucalypts. Populations clustered into three distinct groups, which corresponded to its disjunct natural distribution. Genetic differentiation among populations and between regions was highly significant. Relatively high levels of inbreeding (tm = 0.57) were detected in natural populations of E.�cladocalyx. Outcrossing rates were highly variable among families, ranging from 0 to 100%. One-third of families from four populations had outcrossing rates that were not significantly different from zero. The origins of three commercially significant, cultivated stands of E. cladocalyx were also assessed. Allozyme profiles of cultivated stands from Wail and Lismore in western Victoria suggested origins in the Wirrabara region of the southern Flinders Ranges, while a cultivated stand of E. cladocalyx var. nana Hort. ex Yates had an allozyme profile consistent with origins in the Eyre Peninsula region. The results are discussed in relation to the species' morphological variation, biogeography and the implications for its domestication and conservation.

Taxonomic identity of the patagonian frog Atelognathus jeinimenensis (Anura: Neobatrachia) as revealed by molecular and morphometric evidence

Zootaxa ◽  
2011 ◽  
Vol 2880 (1) ◽  
pp. 20 ◽  
Author(s):  
HELEN DÍAZ-PÁEZ ◽  
MARCELA A. VIDAL ◽  
JUAN C. ORTIZ ◽  
CARMEN A. ÚBEDA ◽  
NÉSTOR G. BASSO
Keyword(s):  
Genetic Diversity ◽  
Morphological Analysis ◽  
Single Species ◽  
Geographic Pattern ◽  
Chilean Patagonia ◽  
Nucleotide Data ◽  
D Loop ◽  
Low Levels ◽  
Morphological Differences ◽  
Chilean Populations

The frog genus Atelognathus is currently represented by nine species distributed in Argentinean and Chilean Patagonia. It is mainly distributed in Argentina, and there are only three species in Chile (A. ceii, A. grandisonae and A. jeinimenensis). Regarding the morphological relationships among Atelognathus species, Meriggio et al. (2004) suggest that A. jeinimenensis is more related to A. salai than other species. A. salai was described from Laguna Los Gendarmes (Argentina), 90 km air line from the type locality of A. jeinimenensis. This paper presents a morphological analysis and a study of population genetics using mtDNA nucleotide data from Argentinean and Chilean localities to assess the genetic distance between A. salai and A. jenimenensis. We obtained 477 bp-long d-loop sequences from 51 Atelognathus specimens collected in four localities. According to our results, the morphological differences between A. salai and A. jeinimenensis populations are limited to size, and there are no distinctive characteristics that would separate two species, in addition to which a simple geographic pattern of genetic diversity suggests a single species of Atelognathus. Also, the populations from Chile (Cerro Castillo, RN Lago Jeinimeni and Chile Chico) and Argentina (Laguna de Los Gendarmes) have low levels of genetic divergence that may be consistent with glaciations during the Late Pleistocene. We propose Atelognathus jeinimenensis as a junior synonym of A. salai and that the Chilean populations should be assigned to A. salai.

scholarly journals The paternal and maternal genetic history of Vietnamese populations

2019 ◽  
Vol 28 (5) ◽  
pp. 636-645 ◽  
Author(s):  
Enrico Macholdt ◽  
Leonardo Arias ◽  
Nguyen Thuy Duong ◽  
Nguyen Dang Ton ◽  
Nguyen Van Phong ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Linguistic Diversity ◽  
Genetic History ◽  
Majority Group ◽  
History Of ◽  
Low Levels ◽  
Potential Impact ◽  
The Many ◽  
Male Specific ◽  
Complete Mtdna

AbstractVietnam exhibits great cultural and linguistic diversity, yet the genetic history of Vietnamese populations remains poorly understood. Previous studies focused mostly on the majority Kinh group, and thus the genetic diversity of the many other groups has not yet been investigated. Here we analyze complete mtDNA genome sequences and ~2.3 Mb sequences of the male-specific portion of the Y chromosome from the Kinh and 16 minority populations, encompassing all five language families present in Vietnam. We find highly variable levels of diversity within and between groups that do not correlate with either geography or language family. In particular, the Mang and Sila have undergone recent, independent bottlenecks, while the majority group, Kinh, exhibits low levels of differentiation with other groups. The two Austronesian-speaking groups, Giarai and Ede, show a potential impact of matrilocality on their patterns of variation. Overall, we find that isolation, coupled with limited contact involving some groups, has been the major factor influencing the genetic structure of Vietnamese populations, and that there is substantial genetic diversity that is not represented by the Kinh.

Genetic diversity of the lichen-forming alga, Diplosphaera chodatii, in North America and Europe

2013 ◽  
Vol 45 (6) ◽  
pp. 799-813 ◽  
Author(s):  
Kyle M. FONTAINE ◽  
Elfie STOCKER-WÖRGÖTTER ◽  
Tom BOOTH ◽  
Michele D. PIERCEY-NORMORE
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
North America ◽  
Isolation By Distance ◽  
Water Level Fluctuations ◽  
Free Living ◽  
Climatic Zones ◽  
Algal Symbiont ◽  
Low Levels

AbstractDermatocarpon luridum is a subaquatic lichen which is distributed within temperate climatic zones around the world. It colonizes rock substrata along the shoreline of lakes and rivers of watersheds that regularly experience water level fluctuations. The mycobiont produces perithecia with small, simple spores that are thought to be wind dispersed. The photobiont, Diplosphaera chodatii, occurs both free-living and lichenized but little is known about its distribution and dispersal. The goal of this study was to compare the population structure of the photobiont from lakes and rivers in central North America with those of Europe. Specimens were collected in Manitoba, Canada and Austria. Population structure of the algal symbiont was assessed using the internal transcribed spacer (ITS) of ribosomal DNA (rDNA) and actin gene sequences. Results showed that genetic diversity and gene flow was high within local populations, but gene flow was low between continental populations. Low levels of gene flow between the most distant populations support the isolation-by-distance theory. The photobiont on both continents is also reported to be the photobiont for other lichen species contributing to photobiont availability for D. luridum.

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