scholarly journals Genetic Diversity of Seven Deciduous Azalea Species (Rhododendron spp. section Pentanthera) Native to the Eastern United States

2008 ◽  
Vol 133 (3) ◽  
pp. 374-382 ◽  
Author(s):  
Matthew Chappell ◽  
Carol Robacker ◽  
Tracie M. Jenkins
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Diversity ◽  
Interspecific Variation ◽  
Genetic Distances ◽  
Anthropogenic Activity ◽  
Group Method ◽  
Aflp Analysis ◽  
Eastern United States

Despite the ecologic and economic importance of native deciduous azaleas (Rhododendron L. section Pentanthera G. Don), our understanding of interspecific variation of North American deciduous azalea species comes principally from morphologic studies. Furthermore, little is known concerning intraspecific or interpopulation genetic variation. With ever-increasing loss and fragmentation of native azalea habitat in the eastern United States due to anthropogenic activity, it is imperative that an understanding of natural genetic variation among and within species and populations is acquired. The present study addresses questions of genetic diversity through the use of amplified fragment length polymorphism (AFLP) analysis. Twenty-five populations of seven species of native azalea were analyzed using three primer pairs that amplified a total of 417 bands. Based on analysis of molecular variance (AMOVA) and estimates of Nei's coefficients of gene diversity (H S, H T, and G ST), the majority of variation found in deciduous azalea occurs within populations. Variation both among species and among population was low, likely the effect of common ancestry as well as frequent introgression among members (and populations) of section Pentanthera. The latter was evident in four populations of R. prunifolium (Small) Millais and R. canescens (Michaux) Sweet that were highly related to R. austrinum (Small) Rehder and R. viscosum (L.) Torrey, respectively. Despite these outliers, most populations were grouped into species based on Nei's unbiased genetic distances viewed as an unweighted pair group method with arithmetic mean (UPGMA) phenogram. The significance of these results is discussed in relation to breeding in section Pentanthera.

scholarly journals Molecular Genetic Variability of Spigelia marilandica and S. gentianoides

2015 ◽  
Vol 140 (2) ◽  
pp. 120-128
Author(s):  
Amanda J. Hershberger ◽  
Tracie M. Jenkins ◽  
Carol Robacker
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Variability ◽  
Gene Diversity ◽  
Molecular Genetic ◽  
Genetic Distances ◽  
Population Variation ◽  
Group Method ◽  
Polymorphism Analysis ◽  
Two Samples

Despite the ecologic and ornamental potential of southeastern U.S. native Spigelia, little is known about the intraspecific or the interpopulation genetic variation. The southeastern U.S. native Spigelia habitat is becoming more and more fragmented as a result of human activity, making it imperative to gain an understanding of natural genetic variation among and within species and populations for the purpose of obtaining variability for plant breeding and preserve the genetic variability in Spigelia. Therefore, the objective of this study was to use amplified fragment length polymorphism analysis to determine interspecific and intraspecific genetic variation and to evaluate gene flow. Thirteen populations of two species of native Spigelia, S. marilandica (SM), S. gentianoides var. gentianoides (SGG), and S. gentianoides var. alabamensis (SGA), were analyzed using four primer pairs that amplified a total of 269 bands. Based on analysis of molecular variance and estimates of Nei’s coefficients of gene diversity (percentage of polymorphic loci, average genetic diversity within populations, average genetic diversity within species, and proportion of species genetic diversity attributed to among population variation), the majority of variation found in Spigelia occurs within populations. Both among-species and among-population variation was low, likely the effect of common ancestry as well as relatively frequent introgression among individuals (and populations) of Spigelia. When all individuals were evaluated using Nei’s unbiased genetic distances and viewed as a unweighted pair group method with arithmetic mean phenogram, three main groups were shown, one with two samples of SGG from one population, one with 13 individuals from both SGG populations used in this study, and one with all of the SM, SGA, and remaining SGG individuals. Further evaluation using STRUCTURE software showed introgression between populations and species, although all allele clusters have not entirely introgressed into all populations. The significance of these results is discussed in relation to breeding in Spigelia.

AFLP-based assessment of genetic diversity among nine alfalfa germplasms using bulk DNA templates

Genome ◽  
2003 ◽  
Vol 46 (1) ◽  
pp. 51-58 ◽  
Author(s):  
A Segovia-Lerma ◽  
R G Cantrell ◽  
J M Conway ◽  
I M Ray
Keyword(s):  
Genetic Diversity ◽  
Medicago Sativa ◽  
High Throughput ◽  
Genetic Distances ◽  
Group Method ◽  
Aflp Analysis ◽  
Dna Templates ◽  
Arithmetic Average ◽  
Pair Group ◽  
Large Numbers

Improving commercial utilization of perennial Medicago collections requires developing approaches that can rapidly and accurately characterize genetic diversity among large numbers of populations. This study evaluated the potential of using amplified fragment length polymorphism (AFLP) DNA markers, in combination with DNA bulking over multiple genotypes, as a strategy for high-throughput characterization of genetic distances (D) among alfalfa (Medicago sativa L.) accessions. Bulked DNA templates from 30 genotypes within each of nine well-recognized germplasms (African, Chilean, Flemish, Indian, Ladak, Medicago sativa subsp. falcata, Medicago sativa subsp. varia, Peruvian, and Turkistan) were evaluated using 34 primer combinations. A total of 3754 fragments were identified, of which 1541 were polymorphic. The number of polymorphic fragments detected per primer combination ranged from 20 to 85. Pairwise D estimates among the nine germplasms ranged from 0.52 to 1.46 with M. sativa subsp. falcata being the most genetically dissimilar. Unweighted pair-group method arithmetic average (UPGMA) analysis of the marker data produced two main clusters, (i) M. sativa subsp. sativa and M. sativa subsp. varia, and (ii) M. sativa subsp. falcata. Cluster-analysis results and D estimates among the Chilean, Peruvian, Flemish, and M. sativa subsp. varia germplasms supported the hypothesis that Peruvian was more similar to original Spanish introductions into Central and South America than Chilean. Hierarchical arrangement of the nine germplasms was supported by their respective geographic, subspecific, and intersubspecific hybrid origins. Subsets of as few as seven highly informative primer pairs were identified that produced comparable D estimates and similar heirarchical arrangements compared with the complete dataset. The results indicate that use of primer-pair subsets for AFLP analysis of bulk DNA templates could serve as a high-throughput system for accurately characterizing genetic diversity among large numbers of alfalfa populations.Key words: Medicago sativa, DNA bulking, genetic distance.

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.

scholarly journals Genetic Diversity of Lowbush Blueberry throughout its U.S. Native Range in Managed and Non-managed Populations

2019 ◽  
Author(s):  
Lee Beers ◽  
Jeannie Rowland ◽  
Francis Drummond
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Polymerase Chain Reaction ◽  
Genetic Variation ◽  
Geographic Range ◽  
Eastern United States ◽  
Native Range ◽  
Chain Reaction ◽  
Lowbush Blueberry ◽  
Polymerase Chain

Expressed sequenced tagged-polymerase chain reaction (EST-PCR) molecular markers were used to evaluate the genetic diversity of lowbush blueberry across its geographic range and to compare genetic diversity among four paired managed/non-managed populations. Seventeen lowbush blueberry populations were sampled in a general north south transect throughout eastern United States with distances between 27 km to 1600 km separating populations. Results show that the majority of genetic variation is found within populations (75%) versus among populations (25%), and that each population was genetically unique (P ≤ 0.0001) with the exception of the Jonesboro, ME and Lubec, ME populations that were found not to be significantly different (P = 0.228). The effects of management for commercial fruit harvesting on genetic diversity were investigated in four locations in Maine with paired managed and non-managed populations. Significant differences were found between the populations indicating that commercial management influences the genetic diversity of lowbush blueberries in the landscape, despite the fact that planting does not occur; forests are harvested and the existing understory blueberry plants are what become established.

scholarly journals Genetic diversity analysis of tropical sugar beet (Beta vulgaris L.) varieties in Bangladesh using RAPD markers

Genetika ◽  
2016 ◽  
Vol 48 (1) ◽  
pp. 151-164
Author(s):  
Saidin Saclain ◽  
Abdul Latif ◽  
Babul Bala ◽  
Mithun Mallik ◽  
Shahidul Islam
Keyword(s):  
Genetic Variation ◽  
Sugar Beet ◽  
Genetic Distance ◽  
Rapd Markers ◽  
Gene Diversity ◽  
Similarity Index ◽  
Genetic Distances ◽  
Group Method ◽  
Pair Group ◽  
Major Cluster

Knowledge on intra-specific genetic variation of an organism is important for its genetic improvement and conservation. In order to estimate genetic variation and relatedness in eleven tropical Sugar beet varieties we used randomly amplified polymorphic DNA (RAPD) markers. The RAPD analysis was performed using six decamer random primers, which amplified a total of 63 DNA fragments of which 43 (68.25%) were found polymorphic. The average polymorphic bands per primer was 7.17 and the overall gene diversity was 0.24. Among the 43 polymorphic loci studied, 2 were specific for 2K 310, 1 for Shubraha, 1 for Natura and 1 for HI-0473 varieties. Pair wise genetic distance and similarity indices were ranged from 0.12-0.51 and 66.73-92.91, respectively. Cauvery and 2K 310 were found to be the most distantly related with a higher genetic distance value (GD = 0.51) and lower similarity index (SI = 66.73), while Aranka and Serenada were the most closely related with their lower GD (0.12) and higher SI(92.91) values. In an unweighted pair group method of arithmetic mean dendrogram constructed on the basis of genetic distances, the eleven varieties grouped into two main clusters: 2K 310 alone was in one cluster whereas 10 other varieties grouped into a major cluster. This indicates that 2K 310 was distantly related with each of the other varieties. Distantly related varieties based on estimated genetic variation could be selected for future breeding program that could result in improvement of this crop.

scholarly journals Genetic Diversity and the Presence of Two Distinct Groups in Ophiostoma clavigerum Associated with Dendroctonus ponderosae in British Columbia and the Northern Rocky Mountains

2007 ◽  
Vol 97 (9) ◽  
pp. 1177-1185 ◽  
Author(s):  
S. Lee ◽  
R. C. Hamelin ◽  
D. L. Six ◽  
C. Breuil
Keyword(s):  
Genetic Diversity ◽  
Mountain Pine Beetle ◽  
Dendroctonus Ponderosae ◽  
Geographic Distance ◽  
The United States ◽  
Genetic Distances ◽  
Group Method ◽  
Aflp Analysis ◽  
Northern Rocky Mountains ◽  
Pair Group

The sapstaining fungal pathogen Ophiostoma clavigerum is associated with the mountain pine beetle (Dendroctonus ponderosae), which is currently the most destructive forest pest in North America. The genetic diversity of O. clavigerum populations collected from five sites in Canada and two sites in the United States was estimated with amplified fragment length polymorphism (AFLP) analysis. Genomic DNA from 170 O. clavigerum isolates was digested with EcoRI and PstI and amplified with six primer sets. A total of 469 AFLP markers consisting of 243 monomorphic and 226 polymorphic loci were scored. The overall genetic diversity of the O. clavigerum population was low (Hs = 0.0531) and the differentiation of the seven O. clavigerum populations was moderate (Φ = 0.143). Genetic distances among the populations were not significantly correlated with geographic distance (r = 0.3235, P = 0.074). Two genetically distinct groups in the O. clavigerum populations were shown by unique AFLP profiles and the unweighted pair group method with arithmetic averages. Further work to characterize biological differences between the two groups will be needed to confirm whether cryptic species are present in the O. clavigerum population.

scholarly journals Assessing Genetic Diversity and Population Structure of Kalmia latifolia L. in the Eastern United States: An Essential Step towards Breeding for Adaptability to Southeastern Environmental Conditions

2020 ◽  
Vol 12 (19) ◽  
pp. 8284
Author(s):  
He Li ◽  
Matthew Chappell ◽  
Donglin Zhang
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Environmental Conditions ◽  
Population Variation ◽  
Group Method ◽  
Eastern United States ◽  
Kalmia Latifolia ◽  
Essential Step ◽  
Genetic Diversity And Structure

Kalmia latifolia L. (mountain laurel), an attractive flowering shrub, is considered to be a high-value ornamental plant for the eastern United States. Limited information on the genetic diversity and structure of K. latifolia is available, which obstructs efficient germplasm utilization and breeding for adaptability to southeastern environmental conditions. In this study, the genetic diversity of 48 wild K. latifolia plants sampled from eight populations in the eastern U.S. was assessed using eight inter simple sequence repeat (ISSR) markers. A total of 116 bands were amplified, 90.52% of which (105) were polymorphic. A high level of genetic diversity at the species level was determined by Nei’s gene diversity (0.3089) and Shannon’s information index (0.4654), indicating that K. latifolia was able to adapt to environmental changes and thus was able to distribute over a wide latitudinal range. In terms of the distribution of genetic diversity, Nei’s genetic differentiation and analysis of molecular variance (AMOVA) showed 38.09% and 29.54% of diversity existed among populations, respectively, elucidating a low-to-moderate level of among-population genetic differentiation. Although a relatively large proportion of diversity was attributed to within-population variation, low diversity within populations (mean genetic diversity within populations (HS) = 0.19) was observed. Both STRUCTURE and unweighted pair group method with arithmetic mean (UPGMA) dendrograms exhibited the clustering of populations that inhabit the same geographic region, and four clusters correlated with four geographic regions, which might be attributed to insect pollination, small population size, and environmental conditions in different habitats. These results function as an essential step towards better conserving and utilizing wild K. latifolia resources, and hence promoting its genetic improvement and breeding for adaptability to southeastern environmental conditions.

scholarly journals Genetic Diversity Among Some Walnut (Juglans regia L.) Genotypes by SSR Markers

2021 ◽  
Vol 13 (12) ◽  
pp. 6830
Author(s):  
Murat Guney ◽  
Salih Kafkas ◽  
Hakan Keles ◽  
Mozhgan Zarifikhosroshahi ◽  
Muhammet Ali Gundesli ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Plant Genetic Resources ◽  
Juglans Regia ◽  
Genetic Distances ◽  
Mean Value ◽  
Central Anatolia ◽  
Group Method ◽  
Arithmetic Average ◽  
Pair Group ◽  
Principal Coordinates

The food needs for increasing population, climatic changes, urbanization and industrialization, along with the destruction of forests, are the main challenges of modern life. Therefore, it is very important to evaluate plant genetic resources in order to cope with these problems. Therefore, in this study, a set of ninety-one walnut (Juglans regia L.) accessions from Central Anatolia region, composed of seventy-four accessions and eight commercial cultivars from Turkey, and nine international reference cultivars, was analyzed using 45 SSR (Simple Sequence Repeats) markers to reveal the genetic diversity. SSR analysis identified 390 alleles for 91 accessions. The number of alleles per locus ranged from 3 to 19 alleles with a mean value of 9 alleles per locus. Genetic dissimilarity coefficients ranged from 0.03 to 0.68. The highest number of alleles was obtained from CUJRA212 locus (Na = 19). The values of polymorphism information content (PIC) ranged from 0.42 (JRHR222528) to 0.86 (CUJRA212) with a mean PIC value of 0.68. Genetic distances were estimated according to the UPGMA (Unweighted Pair Group Method with Arithmetic Average), Principal Coordinates (PCoA), and the Structure-based clustering. The UPGMA and Structure clustering of the accessions depicted five major clusters supporting the PCoA results. The dendrogram revealed the similarities and dissimilarities among the accessions by identifying five major clusters. Based on this study, SSR analyses indicate that Yozgat province has an important genetic diversity pool and rich genetic variance of walnuts.

Genetic Diversity of Wild Oat (Avena fatua)Populations from China and the United States

Weed Science ◽  
2007 ◽  
Vol 55 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Runzhi Li ◽  
Shiwen Wang ◽  
Liusheng Duan ◽  
Zhaohu Li ◽  
Michael J. Christoffers ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
The United States ◽  
Mantel Test ◽  
Wild Oat ◽  
Chinese Populations ◽  
Nei's Distance ◽  
The Impact

Weed genetic diversity is important for understanding the ability of weeds to adapt to different environments and the impact of herbicide selection on weed populations. Genetic diversity within and among six wild oat populations in China varying in herbicide selection pressure and one population in North Dakota were surveyed using 64 polymorphic alleles resulting from 25 microsatellite loci. Mean Nei's gene diversity (h) for six wild oat populations from China was between 0.17 and 0.21, and total diversity (HT) was 0.23. A greater proportion of this diversity, however, was within (Hs= 0.19) rather than among (Gst= 0.15) populations. For the wild oat population from the United States,h= 0.24 andHT= 0.24 were comparable to the values for the six populations from China. Cluster analysis divided the seven populations into two groups, where one group was the United States population and the other group included the six Chinese populations. The genetic relationships among six populations from China were weakly correlated with their geographic distribution (r= 0.22) using the Mantel test. Minimal difference in gene diversity and small genetic distance (Nei's distance 0.07 or less) among six populations from China are consistent with wide dispersal of wild oat in the 1980s. Our results indicate that the wild oat populations in China are genetically diverse at a level similar to North America, and the genetic diversity of wild oat in the broad spatial scale is not substantially changed by environment, agronomic practices, or herbicide usage.

scholarly journals Genetic diversity in table grapes based on RAPD and microsatellite markers

2011 ◽  
Vol 46 (9) ◽  
pp. 1035-1044 ◽  
Author(s):  
Patrícia Coelho de Souza Leão ◽  
Sérgio Yoshimitsu Motoike
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Genetic Relationships ◽  
Similarity Index ◽  
Genetic Distances ◽  
Table Grape ◽  
Group Method ◽  
Molecular Characteristics ◽  
Table Grapes ◽  
Pair Group

The objective of this work was to analyze the genetic diversity of 47 table grape accessions, from the grapevine germplasm bank of Embrapa Semiárido, using 20 RAPD and seven microsatellite markers. Genetic distances between pairs of accessions were obtained based on Jaccard's similarity index for RAPD data and on the arithmetic complement of the weighted index for microsatellite data. The groups were formed according to the Tocher's cluster analysis and to the unweighted pair‑group method with arithmetic mean (UPGMA). The microsatellite markers were more efficient than the RAPD ones in the identification of genetic relationships. Information on the genetic distance, based on molecular characteristics and coupled with the cultivar agronomic performance, allowed for the recommendation of parents for crossings, in order to obtain superior hybrids in segregating populations for the table grape breeding program of Embrapa Semiárido.

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