scholarly journals Cross-species transferability of Solanum spp. DNA markers and their application in assessing genetic variation in silverleaf nightshade (Solanum elaeagnifolium) populations from Texas, USA

Weed Science ◽  
2020 ◽  
Vol 68 (4) ◽  
pp. 396-404 ◽  
Author(s):  
Joshua James Singleton ◽  
Puneet Kaur Mangat ◽  
Junghyun Shim ◽  
Cody Vavra ◽  
Cade Coldren ◽  
...  
Keyword(s):  
Invasive Species ◽  
Genetic Variation ◽  
Phenotypic Plasticity ◽  
Dna Markers ◽  
The United States ◽  
Group Method ◽  
Genetic Adaptation ◽  
Selection Pressures ◽  
Silverleaf Nightshade ◽  
Solanum Elaeagnifolium

AbstractSilverleaf nightshade (Solanum elaeagnifolium Cav.) is an invasive species that has successfully spread outside its native range to become a noxious weed in 21 states in the United States and 42 countries worldwide. The successful establishment of S. elaeagnifolium outside its native habitat indicates its innate ability to adapt to a multitude of environments. Phenotypic plasticity and/or genetic adaptation have been identified as key mechanisms underlying the adaptive success of invasive species. Whereas phenotypic plasticity allows a species to buffer changes in the environment by altering its phenotypic attributes within the short term, genetic adaptation is responsible for the longer-term adaptability of plants to heterogeneous environments and is dependent on the amount of genetic variation present in the species. In this study, we screened DNA markers that are specific to tomato (Solanum lycopersicum L.) and Solanum lycopersicoides Dunal for their interspecific transferability to S. elaeagnifolium and determined the applicability of the transferable DNA markers in assessing the extent of genetic variation in populations from Lubbock, Littlefield, and Blackwell, TX. Of the 187 markers screened, 78 successfully amplified targets in S. elaeagnifolium, indicating the evolutionary conservation of marker loci across S. lycopersicum, S. lycopersicoides, and S. elaeagnifolium, despite their genetic divergence millions of years ago. Genotyping of S. elaeagnifolium populations using 50 DNA markers that consistently amplified clear bands in more than 60% of the plants identified nine polymorphic markers with 0.014 to 0.621 polymorphism information content. Genetic diversity analysis by DNA marker profiling established genetic variation among populations and within individuals of different populations. Unweighted paired group method with arithmetic mean analysis grouped the plants into six clusters that are generally defined by selection pressures unique to each collection site. Results of the study indicate the capacity of S. elaeagnifolium for genetic differentiation in response to variable selection pressures within the same geographic region.

Knotweed Management Strategies in North America with the Advent of Widespread Hybrid Bohemian Knotweed, Regional Differences, and the Potential for Biocontrol Via the Psyllid Aphalara itadori Shinji

2016 ◽  
Vol 9 (1) ◽  
pp. 60-70 ◽  
Author(s):  
David R. Clements ◽  
Todd Larsen ◽  
Jennifer Grenz
Keyword(s):  
Biological Control ◽  
Invasive Species ◽  
Genetic Variation ◽  
North America ◽  
North American ◽  
Regional Differences ◽  
The United States ◽  
The North ◽  
Variable Nature ◽  
Available Resources

AbstractInvasive species with distributions that encompass much of the North American environment often demand a range of management approaches, for several key reasons. Firstly, the North American environment includes a large number of highly variable habitats in terms of climatic, edaphic, and landscape features. Secondly, these regional habitat differences are accentuated by jurisdictions within Canada and the United States, whereby approaches and available resources differ at local, regional, and national scales. Another important consideration is whether an invasive species or complex also possesses genetic variation. All three of these factors render the knotweed complex in North America a highly variable target for management. In this paper we review existing knowledge of the variable nature of knotweed species (Fallopia japonica (Houtt.) Ronse Decr., Fallopia sachalinensis (F. Schmidt ex Maxim) Ronse Decr., and Fallopia × bohemica, (Chrtek and Chrtková) J. P. Bailey in North America, and evaluate how herbicidal, mechanical and biological control measures must account for this genetic variation, as well as accounting for regional differences and the potential northward expansion of knotweed under climate change. The imminent release of the psyllid, Aphalara itadori Shinji as a biological control agent in North America must also navigate regional and genetic differences. Prior European experience dealing with the three knotweed species should prove useful, but additional research is needed to meet the emerging challenge posed by F. × bohemica in North America, including the possibility of glyphosate resistance. Managers also face challenges associated with posttreatment restoration measures. Furthermore, disparities in resources available to address knotweed management across the continent need to be addressed to contain the rapid spread of this highly persistent and adaptable species. Linking practitioners dealing with knotweed “on the ground” with academic research is a crucial step in the process of marshalling all available resources to reduce the rapidly spreading populations of knotweed.

scholarly journals A Survey of Genetic Variation in Streptomyces Isolates Causing Potato Common Scab in the United States

2006 ◽  
Vol 96 (12) ◽  
pp. 1363-1371 ◽  
Author(s):  
Leslie A. Wanner
Keyword(s):  
United States ◽  
Genetic Variation ◽  
Common Scab ◽  
Disease Incidence ◽  
The United States ◽  
Rrna Gene ◽  
Population Genetic Study ◽  
Variable Regions ◽  
Genus Streptomyces ◽  
Characteristic Features

Common scab is a serious disease of potatoes and other root and tuber crops, affecting crop quality and market value. The disease is caused by gram positive soil bacteria in the genus Streptomyces. Disease incidence and severity vary in different locations and years; this is due in part to variation in the environment (weather) and genetic variation in potato cultivars. Little information is available on the contribution of genetic variation by the pathogen. To examine genetic diversity in different locations within the United States, streptomycetes were isolated from lesions on field-grown potatoes from six states. Isolates were classified into species based on sequence of variable regions in the 16s rRNA gene. The presence of genes associated with the recently described S. turgidiscabies pathogenicity island (PAI) was also determined. About half of the isolates belonged to S. scabies or S. europaeiscabiei based on 16s rDNA sequence, and had characteristic features of the PAI. They were found in all six states, and were pathogenic on potato and radish. The remaining isolates included pathogens and nonpathogens. They were varied in appearance, and represent several species, including one pathogenic species not previously reported. Some pathogenic isolates lacked one or more genes characteristic of the PAI, although all had genes for biosynthesis of the pathogenicity determinant thaxtomin. In this relatively small survey, regional differences in scab-causing streptomycetes were seen. This report furnishes tools and baseline data for population genetic study of scab-causing streptomycetes in the United States.

Genetic variation and evolutionary relationships amongst bluetongue viruses endemic in the United States

1991 ◽  
Vol 21 (2) ◽  
pp. 91-109 ◽  
Author(s):  
H.W. Heidner ◽  
L.G. Iezzi ◽  
B.I. Osburn ◽  
N.J. MacLachlan
Keyword(s):  
United States ◽  
Genetic Variation ◽  
The United States ◽  
Evolutionary Relationships

Revitalizing Difference in the HapMap: Race and Contemporary Human Genetic Variation Research

2008 ◽  
Vol 36 (3) ◽  
pp. 471-477 ◽  
Author(s):  
Jennifer A. Hamilton
Keyword(s):  
Genetic Variation ◽  
Human Genome ◽  
Genetic Research ◽  
The United States ◽  
Genome Project ◽  
Human Genetic Variation ◽  
Early 21St Century ◽  
The Social ◽  
English Speaking ◽  
The Human Genome Project

In 2000, researchers from the Human Genome Project (HGP) proclaimed that the initial sequencing of the human genome definitively proved, among other things, that there was no genetic basis for race. The genetic fact that most humans were 99.9% the same at the level of their DNA was widely heralded and circulated in the English-speaking press, especially in the United States. This pronouncement seemed proof that long-term antiracist efforts to de-biologize race were legitimized by scientific findings. Yet, despite the seemingly widespread acceptance of the social construction of race, post-HGP genetic science has seen a substantial shift toward the use of race variables in genetic research and, according to a number of prominent scholars, is re-invoking the specter of earlier forms of racial science in some rather discomfiting ways. During the past seven years, the main thrust of human genetic research, especially in the realm of biomedicine, has shifted from a concern with the 99.9% of the shared genome — what is thought to make humans alike — towards an explicit focus on the 0.1% that constitutes human genetic variation. Here I briefly explore some of the potential implications of the conceptualization and practice of early 21st century genetic variation research, especially as it relates to questions of race.

scholarly journals Detection of DNA and Ploidy Variation within Vegetatively Propagated Zoysiagrass Cultivars

2014 ◽  
Vol 139 (5) ◽  
pp. 547-552 ◽  
Author(s):  
Karen R. Harris-Shultz ◽  
Susana Milla-Lewis ◽  
Aaron J. Patton ◽  
Kevin Kenworthy ◽  
Ambika Chandra ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Reference Sample ◽  
Warm Season ◽  
The United States ◽  
Group Method ◽  
Group Iii ◽  
Climatic Regions ◽  
Pair Group ◽  
Group I ◽  
Two Samples

Zoysiagrass (Zoysia sp.) is used as a warm-season turfgrass for lawns, parks, and golf courses in the warm, humid and transitional climatic regions of the United States. Zoysiagrass is an allotetraploid species (2n = 4x = 40) and some cultivars are known to easily self- and cross-pollinate. Previous studies showed that genetic variability in the clonal cultivars Emerald and Diamond was likely the result of contamination (seed production or mechanical transfer) or mislabeling. To determine the extent of genetic variability of vegetatively propagated zoysiagrass cultivars, samples were collected from six commercially available zoysiagrass cultivars (Diamond, Emerald, Empire, JaMur, Meyer, Zeon) from five states (Arkansas, Florida, Georgia, North Carolina, Texas). Two of the newest cultivar releases (Geo and Atlantic) were to serve as outgroups. Where available, one sample from university research plots and two samples from sod farms were collected for each cultivar per state. Forty zoysiagrass simple sequence repeat (SSR) markers and flow cytometry were used to compare genetic and ploidy variation of each collected sample to a reference sample. Seventy-five samples were genotyped and an unweighted pair group method with arithmetic mean clustering revealed four groups. Group I (Z. japonica) included samples of ‘Meyer’ and Empire11 (‘Empire’ sample at location #11), Group II (Z. japonica × Z. pacifica) included samples of ‘Emerald’ and ‘Geo’, Group III (Z. matrella) included samples of ‘Diamond’ and ‘Zeon’, and Group IV (Z. japonica) consisted of samples from ‘Empire’, ‘JaMur’, ‘Atlantic’, and Meyer3 (‘Meyer’ at sample location #3). Samples of ‘Empire’, ‘Atlantic’, and ‘JaMur’ were indistinguishable with the markers used. Four samples were found to have alleles different from the respective reference cultivar, including two samples of ‘Meyer’, one sample of ‘Empire’, and one sample of ‘Emerald’. Three of these samples were from Texas and one of these samples was from Florida. Three of the four samples that were different from the reference cultivar were university samples. In addition, one sample, Empire11, was found to be an octoploid (2n = 8x = 80). For those samples that had a fingerprint different from the reference cultivar, contamination, selfing, and/or hybridization with other zoysiagrasses may have occurred.

scholarly journals Potential for rapid genetic adaptation to warming in a Great Barrier Reef coral

2017 ◽  
Author(s):  
Mikhail V. Matz ◽  
Eric A. Treml ◽  
Galina V. Aglyamova ◽  
Madeleine J. H. van Oppen ◽  
Line K. Bay
Keyword(s):  
Genetic Variation ◽  
Great Barrier Reef ◽  
Coral Cover ◽  
Reef Coral ◽  
Biophysical Model ◽  
Detectable Effect ◽  
Genetic Adaptation ◽  
Barrier Reef ◽  
Biophysical Modeling ◽  
Adaptive Genetic Variation

AbstractCan genetic adaptation in reef-building corals keep pace with the current rate of sea surface warming? Here we combine population genomic, biophysical modeling, and evolutionary simulations to predict future adaptation of the common coralAcropora milleporaon the Great Barrier Reef. Loss of coral cover in recent decades did not yet have detectable effect on genetic diversity in our species. Genomic analysis of migration patterns closely matched the biophysical model of larval dispersal in favoring the spread of existing heat-tolerant alleles from lower to higher latitudes. Given these conditions we find that standing genetic variation could be sufficient to fuel rapid adaptation ofA. milleporato warming for the next 100-200 years, although random thermal anomalies would drive increasingly severe mortality episodes. However, this adaptation will inevitably cease unless the warming is slowed down, since no realistic mutation rate could replenish adaptive genetic variation fast enough.

scholarly journals Genetic Variation among and within United States Collard Cultivars and Landraces as Determined by Randomly Amplified Polymorphic DNA Markers

1996 ◽  
Vol 121 (3) ◽  
pp. 374-379 ◽  
Author(s):  
Mark W. Farnham
Keyword(s):  
Genetic Variation ◽  
Dna Markers ◽  
Crop Improvement ◽  
Similarity Index ◽  
Randomly Amplified Polymorphic Dna ◽  
Brussels Sprouts ◽  
Breeding Lines ◽  
Intrapopulation Variation ◽  
Similarity Indices ◽  
Systematic Collection

A collection of collard (Brassica oleracea L., Acephala group) germplasm, including 13 cultivars or breeding lines and 5 landraces, was evaluated using randomly amplified polymorphic DNA (RAPD) markers and compared to representatives of kale (Acephala group), cabbage (Capitata group), broccoli (Italica group), Brussels sprouts (Gemmifera group), and cauliflower (Botrytis group). Objectives were to assess genetic variation and relationships among collard and other crop entries, evaluate intrapopulation variation of open-pollinated (OP) collard lines, and determine the potential of collard landraces to provide new B. oleracea genes. Two hundred nine RAPD bands were scored from 18 oligonucleotide decamer primers when collard and other B. oleracea entries were compared. Of these, 147 (70%) were polymorphic and 29 were specific to collard. Similarity indices between collard entries were computed from RAPD data and these ranged from 0.75 to 0.99 with an average of 0.83. Collard entries were most closely related to cabbage (similarity index = 0.83) and Brussels sprouts entries (index = 0.80). Analysis of individuals of an OP cultivar and landrace indicated that intrapopulation genetic variance accounts for as much variation as that observed between populations. RAPD analysis identified collard landraces as unique genotypes and showed them to be sources of unique DNA markers. The systematic collection of collard landraces should enhance diversity of the B. oleracea germplasm pool and provide genes for future crop improvement.

Sign in / Sign up

Export Citation Format

Share Document