scholarly journals Genetic Diversity and Geographic Differentiation in Pawpaw [Asimina triloba (L.) Dunal] Populations from Nine States as Revealed by Allozyme Analysis

1998 ◽  
Vol 123 (4) ◽  
pp. 635-641 ◽  
Author(s):  
Hongwen Huang ◽  
Desmond R. Layne ◽  
Don E. Riemenschneider
Keyword(s):  
Genetic Diversity ◽  
New York ◽  
Germplasm Collection ◽  
Principal Component ◽  
Major Group ◽  
State University ◽  
Allozyme Diversity ◽  
Woody Perennial ◽  
Asimina Triloba ◽  
Hardy Weinberg Equilibrium

As a new National Clonal Germplasm Repository for Asimina species at Kentucky State University (KSU), of major concern to us is the genetic variation within our germplasm collection. The present study investigated the extent of genetic diversity for the pawpaw germplasm in our collection and the geographical pattern of genetic diversity among populations using isozyme markers. Allozyme diversity was high in Asimina triloba (L.) Dunal (Annonaceae) collected from all nine different states, as is typical for temperate woody perennial, widespread and outcrossing plant species. Averaged across populations, mean number of alleles per locus (A), percent polymorphic loci (P), effective number of alleles per locus (Ae), and expected heterozygosity (He) were 1.54, 43.5, 1.209, and 0.172, respectively. Significant deviations from Hardy-Weinberg equilibrium were found in nine populations at an average of 4.8 loci. Observed heterozygosity was higher than expected. Partitioning of genetic diversity showed that 88.2% resided within populations. The proportion of genetic diversity among populations (Gst = 0.118; FST = 0.085) was either lower than or within the range of those species with similar ecological and life-history traits. The mean genetic identity among populations was high (I = 0.988). An analysis using UPGMA clustered most populations as one major group, with the southernmost (Georgia) and the westernmost (Illinois) populations readily separated from the main group. The relationships discovered by principal component analysis (PCA) were similar to those revealed by UPGMA. In addition, PCA separated the northernmost population (New York) from the major group. Sampling strategies for future germplasm collection of A. triloba are also discussed.

scholarly journals Pawpaw [Asimina triloba (L.) Dunal] Germplasm Evaluation Using RAPD Markers

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 513D-513
Author(s):  
Hongwen Huang ◽  
Desmond R. Layne ◽  
Thomas L. Kubisiak
Keyword(s):  
Genetic Diversity ◽  
Rapd Markers ◽  
Germplasm Collection ◽  
Germplasm Evaluation ◽  
Genetic Enhancement ◽  
Similar Species ◽  
Native Range ◽  
Woody Perennial ◽  
Asimina Triloba ◽  
Species Characteristics

Kentucky State Univ. (KSU) is the national clonal germplasm repository for Asimina species. Previous evaluation of the KSU pawpaw collection using 24 isozyme markers demonstrated that pawpaw has a relatively higher genetic diversity than that noted for other plant species with similar species characteristics (long-lived, woody, perennial, out-crossing, temperate, widespread, etc.). Current evaluation using RAPD markers will provide us with a more-accurate insight into pawpaw genetic diversity and population structure. In a preliminary experiment, one hundred 10-mer primers (OA1-20 through OE1-20, Operon Technologies Inc.) were screened against 32 commercial cultivars or advanced selections. A subset of 24 primers that amplify only the most-informative markers were used for germplasm evaluation. Sixty-eight RAPD markers were identified and used for determining genetic parameters. One-hundred-twenty pawpaw accessions were sampled from the KSU repository for RAPD analysis. These accessions represented nine widely distributed states within pawpaw's native range. RAPD data were subjected to various analyses using the NTSYS-PC computer program (ver. 1.8). Information generated from isozyme and RAPD markers will be used to formulate future germplasm collection strategies from wild populations within the native range. The implications of such information to the genetic enhancement of our repository and establishment of a core collection will be discussed.

Genetic Analysis of Chinese Cucumber Collections in the U.S. National Germplasm Collection

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 534e-534 ◽  
Author(s):  
J. Staub ◽  
Felix Sequen ◽  
Tom Horejsi ◽  
Jin Feng Chen
Keyword(s):  
Genetic Diversity ◽  
Principal Component Analysis ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Allelic Variation ◽  
Germplasm Collection ◽  
Principal Component ◽  
Isozyme Loci ◽  
National Plant Germplasm System ◽  
The U.S

Genetic variation in cucumber accessions from China was assessed by examining variation at 21 polymorphic isozyme loci. Principal component analysis of allelic variation allowed for the depiction of two distinct groupings of Chinese accessions collected in 1994 and 1996 (67 accessions). Six isozyme loci (Gpi, Gr, Mdh-2, Mpi-2, Pep-gl, and Pep-la) were important in elucidating these major groups. These groupings were different from a single grouping of Chinese 146 accessions acquired before 1994. Allelic variation in Chinese accessions allowed for comparisons with other accessions in the U.S. National Plant Germplasm System (U.S. NPGS) collection grouped by continent and sub-continent. When Chinese accessions taken collectively were compared with an array of 853 C. sativus U.S. NPGS accessions examined previously, relationships differed between accessions grouped by country or subcontinent. Data indicate that acquisition of additional Chinese and Indian cucumber accessions would be strategically important for increasing genetic diversity in the U.S. NPGS cucumber collection.

Analysis of genetic diversity in an invasive population of Asian long-horned beetles in Ontario, Canada

2009 ◽  
Vol 141 (6) ◽  
pp. 582-594 ◽  
Author(s):  
Maureen E. Carter ◽  
Michael T. Smith ◽  
Jean J. Turgeon ◽  
Richard G. Harrison
Keyword(s):  
Genetic Diversity ◽  
New York ◽  
New York City ◽  
York City ◽  
Haplotype Diversity ◽  
Population Based ◽  
Nonrandom Mating ◽  
Founding Population ◽  
Hardy Weinberg Equilibrium ◽  
Horned Beetles

AbstractAdult Asian long-horned beetles, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae: Lamiinae), were discovered in Ontario, Canada, in 2003 in the vicinity of a commercial warehouse. Trees were heavily scarred with signs of attack and larvae and adult beetles were common, suggesting that there had been multiple generations at the site. We amplified 16 microsatellite loci from 326 beetles to examine genetic diversity in this population. Based on Hardy – Weinberg equilibrium, 6 of 16 loci were monomorphic and 8 were not, indicating nonrandom mating. Measures of microsatellite genetic diversity and mitochondrial DNA haplotype diversity were significantly lower than those in A. glabripennis from China and Korea but were not significantly different from those in the New York City population. The proportion of different multilocus genotypes in the Ontario population was lower than in the populations in New York City and Linden, New Jersey. These results suggest that limited genetic diversity in the Ontario population has not hampered reproduction of this invasive insect. This genetic signature is common in other invasive species, likely because a population is founded by a few closely related individuals, or a large founding population suffers subsequent genetic bottlenecks.

scholarly journals RAPD Inheritance and Diversity in Pawpaw (Asimina triloba)

2000 ◽  
Vol 125 (4) ◽  
pp. 454-459 ◽  
Author(s):  
Hongwen Huang ◽  
Desmond R. Layne ◽  
Thomas L. Kubisiak
Keyword(s):  
Genetic Diversity ◽  
New York ◽  
West Virginia ◽  
Goodness Of Fit ◽  
Genetic Relationships ◽  
Interspecific Cross ◽  
The Other ◽  
Asimina Triloba ◽  
Total Genetic Diversity ◽  
Natural Range

Twelve, 10-base primers amplified a total of 20 intense and easily scorable polymorphic bands in an interspecific cross of PPF1-5 pawpaw [Asimina triloba (L.) Dunal.] × RET (Asimina reticulata Shuttlew.). In this cross, all bands scored were present in, and inherited from, the A. triloba parent PPF1-5. Nineteen of the 20 bands were found to segregate as expected (1:1 or 3:1) based on chi-square goodness-of-fit tests, and were subsequently used to evaluate genetic diversity in populations of A. triloba collected from six states (Georgia, Illinois, Indiana, Maryland, New York, and West Virginia) within its natural range. Analysis of genetic diversity of the populations revealed that the mean number of alleles per locus was A = 1.64, percent polymorphic loci was P = 64, and expected heterozygosity was He = 0.25. No significant differences were found among populations for any of the polymorphic indices. Partitioning of the population genetic diversity showed that the average genetic diversity within populations was Hs = 0.26, accounting for 72% of the total genetic diversity. Genetic diversity among populations was Dst = 0.10, accounting for 28% of the total genetic diversity. Nei's genetic identity and distance showed a high mean identity of 0.86 between populations. Genetic relationships among the populations examined by unweighted pair-group mean clustering analysis separated the six populations into two primary clusters: one composed of Georgia, Maryland, and New York, and the other composed of Illinois, Indiana, and West Virginia. The Georgia and Indiana populations were further separated from the other populations within each group. This study provides additional evidence that marginal populations within the natural range of A. triloba should be included in future collection efforts to capture most of the rare and local alleles responsible for this differentiation.

scholarly journals Partitioning of Allozyme Diversity in Wild Populations of Malus sieversii L. and Implications for Germplasm Collection

1996 ◽  
Vol 121 (6) ◽  
pp. 982-987 ◽  
Author(s):  
Warren F. Lamboy ◽  
Jing Yu ◽  
Phil L. Forsline ◽  
Norman F. Weeden
Keyword(s):  
Genetic Diversity ◽  
Germplasm Collection ◽  
Geographic Region ◽  
Seed Parent ◽  
Wild Populations ◽  
Allozyme Diversity ◽  
Malus Sieversii ◽  
Large Populations ◽  
Sib Families ◽  
Geographic Regions

One of the primary progenitors of the cultivated apple is Malus sieversii L., a species native to the forested regions of central Asia. Despite the horticultural importance of M. sieversii, little is known about genetic variation in this species. In this study, allozyme diversity at 18 loci was determined for 259 seedlings belonging to 31 sib families, each consisting of the set of offspring from a different open-pollinated maternal (seed) parent. Maternal parents belonged to 14 populations from four geographic regions. Genetic diversity statistics were computed from the resulting allele and phenotype frequencies. Cluster analysis of sib families showed that there was some grouping based on geographic region, but 16 of the sib families were most closely related to sib families from other regions. Analysis of molecular variance (AMOVA) indicated that 85% of the enzyme variability was due to differences among sib families within populations and 15% was due to differences among regions. No variability could be assigned to differences among populations within regions. In addition, no alleles were found that were fixed in a region and unique to that region. These results suggest that plants belonging to M. sieversii effectively form a panmictic population. Consequently, a thorough sampling of a few large populations will efficiently capture most of the genetic diversity present in wild M. sieversii.

Ecogeographical studies identify diversity and potential gaps in the largest germplasm collection of bladder clover (Trifolium spumosum L.)

2007 ◽  
Vol 58 (7) ◽  
pp. 728 ◽  
Author(s):  
K. Ghamkhar ◽  
R. Snowball ◽  
S. J. Bennett
Keyword(s):  
Genetic Diversity ◽  
Germplasm Collection ◽  
Principal Component ◽  
Collection Site ◽  
Plant Germplasm ◽  
Germplasm Collections ◽  
Ecological Aspects ◽  
Passport Data ◽  
Ecogeographical Diversity ◽  
Germplasm Accessions

Plant germplasm collections are important reservoirs of diversity for plant breeders and adding to the knowledge of the diversity among and within germplasm accessions helps plant breeders to use them more efficiently. The annual legume, bladder clover (Trifolium spumosum L.), was the model plant in this study. The hypothesis that ecogeographical variables are important sources of diversity in the germplasm collection of bladder clover and some variables are more important than others has been studied. Three themes have been addressed here: firstly, analysis of the existing passport data to determine a minimum set of ecogeographical descriptors required for capturing ecological aspects of each collection site; secondly, illustration of the ecogeographical regions and subregions using GIS techniques to identify areas with the greatest likelihood of filling gaps in the collection; thirdly, development of an approach for the evaluation of genetic diversity by grouping accessions with a focus on outliers within the collection using principal component and cluster analyses. In this paper the importance of longitude as a geographical factor has been documented and the overall ecogeographical diversity in the germplasm collection of bladder clover has been screened.

scholarly journals Genetic Diversity of Perennial Ryegrass Wild Ecotypes Based on Agro-Biological Traits

2012 ◽  
Vol 66 (4-5) ◽  
pp. 168-171
Author(s):  
Gražina Statkevičiūtė ◽  
Vilma Kemeðytė ◽  
Nijolė Lemežienė ◽  
Grigorij S. Konik ◽  
Maria Chomiak
Keyword(s):  
Genetic Diversity ◽  
Plant Height ◽  
Perennial Ryegrass ◽  
Flag Leaf ◽  
Genetic Erosion ◽  
Germplasm Collection ◽  
Principal Component ◽  
Winter Survival ◽  
Research Centre ◽  
Biological Traits

Perennial ryegrasses (Lolium perenne L.) are one of the most valuable forage grasses, characterized by high productivity and good feed quality. Intensive cultivation of ryegrasses has resulted in reduced genetic diversity. Wild ryegrass ecotypes can be used in breeding programmes as parental genotypes with the aim to neutralize this genetic erosion. The objective of this study was to evaluate wild perennial ryegrass ecotypes from Ukraine under Lithuanian climatic conditions. Wild ecotypes were collected in Western and Northern Ukraine in 2008-2009 and planted in 2009-2010 as part of the germplasm collection at the Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry. Winter survival, re-growth in spring, plant height, beginning of heading, flag leaf length and width, inflorescence length and biomass were assessed. High variation of traits was detected among ecotypes (CV = 22.64-41.41%), except for winter survival, for which the coefficient of variation was average (CV = 18.26%). Principal component analysis was carried out and a dendrogram was computed based on agro-biological traits. In both years of investigation the grouping of ecotypes was mostly influenced by biomass, plant height and date of heading.

scholarly journals Genetic Variation in Pawpaw Cultivars Using Microsatellite Analysis

2011 ◽  
Vol 136 (6) ◽  
pp. 415-421 ◽  
Author(s):  
Li Lu ◽  
Kirk W. Pomper ◽  
Jeremiah D. Lowe ◽  
Sheri B. Crabtree
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Information Content ◽  
Polymorphism Information Content ◽  
State University ◽  
The Public ◽  
Asimina Triloba ◽  
Major Allele Frequency ◽  
High Polymorphism Information Content ◽  
Major Allele

Pawpaw (Asimina triloba) is a tree fruit native to eastern North America, which is in the early stages of domestication. Most early 20th century pawpaw cultivars have been lost; however, recent cultivar releases and potential new releases may have enhanced genetic diversity. The objective of this study was to compare the genetic variation exhibited among older and new pawpaw cultivars and Kentucky State University (KSU) advanced selections using simple sequence repeat (SSR) markers. Polymorphic microsatellite marker analysis was conducted with nine older pawpaw cultivars, six recently released PawPaw Foundation (PPF) cultivars, and nine KSU advanced selections. Using 18 microsatellite loci, a total of 179 alleles were amplified in the set of 24 genotypes. The major allele frequency (0.13 to 0.96), number of genotypes (two to 23), and allele size (96 to 341 bp) varied greatly by locus. Eighteen loci were highly polymorphic, as indicated by high expected heterozygosity (He = 0.71) and observed heterozygosity (Ho = 0.65) values as well as high polymorphism information content (polymorphism information content = 0.69). The dinucleotide SSR (GA and CA motifs) loci were more polymorphic than trinucleotide (ATG and AAT motifs) SSRs. The PPF cultivars and KSU advanced selections were more closely grouped genetically than with older cultivars. Older cultivars displayed the greatest genetic diversity (Ho = 0.69). The pawpaw cultivar base of older and PPF cultivars does appear to be genetically diverse. However, KSU advanced selections contain unique pawpaw germplasm that should enhance the genetic base of cultivars if these selections are released to the public.

scholarly journals Genetic Analysis of Diversity within a Chinese Local Sugarcane Germplasm Based on Start Codon Targeted Polymorphism

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Youxiong Que ◽  
Yongbao Pan ◽  
Yunhai Lu ◽  
Cui Yang ◽  
Yuting Yang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Polymorphic Information Content ◽  
Germplasm Collection ◽  
Principal Component ◽  
Breeding Value ◽  
Start Codon ◽  
Group Method ◽  
Depth Information ◽  
Scot Marker ◽  
Sugarcane Germplasm

In-depth information on sugarcane germplasm is the basis for its conservation and utilization. Data on sugarcane molecular markers are limited for the Chinese sugarcane germplasm collections. In the present study, 20 start codon targeted (SCoT) marker primers were designed to assess the genetic diversity among 107 sugarcane accessions within a local sugarcane germplasm collection. These primers amplified 176 DNA fragments, of which 163 were polymorphic (92.85%). Polymorphic information content (PIC) values ranged from 0.783 to 0.907 with a mean of 0.861. Unweighted pair group method of arithmetic averages (UPGMA) cluster analysis of the SCoT marker data divided the 107 sugarcane accessions into six clusters at 0.674 genetic similarity coefficient level. Relatively abundant genetic diversity was observed among ROC22, ROC16, and ROC10, which occupied about 80% of the total sugarcane acreage in China, indicating their potential breeding value on Mainland China. Principal component analysis (PCA) partitioned the 107 sugarcane accessions into two major groups, the Domestic Group and the Foreign Introduction Group. Each group was further divided based on institutions, where the sugarcane accessions were originally developed. The knowledge of genetic diversity among the local sugarcane germplasm provided foundation data for managing sugarcane germplasm, including construction of a core collection and regional variety distribution and subrogation.

scholarly journals Assessment of Genetic Diversity of Pawpaw (Asimina triloba) Cultivars with Intersimple Sequence Repeat Markers

2003 ◽  
Vol 128 (4) ◽  
pp. 521-525 ◽  
Author(s):  
Kirk W. Pomper ◽  
Sheri B. Crabtree ◽  
Shawn P. Brown ◽  
Snake C. Jones ◽  
Tera M. Bonney ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Issr Markers ◽  
State University ◽  
Sequence Repeat ◽  
Department Of Agriculture ◽  
Chi Square ◽  
University Of British Columbia ◽  
Asimina Triloba ◽  
High Level ◽  
Chi Square Analysis

The pawpaw [Asimina triloba (L.) Dunal.] is a tree fruit native to many areas of the southeastern and mid-western United States. Kentucky State University (KSU) is designated as a satellite repository for Asimina for the U.S. Department of Agriculture (USDA), National Plant Germplasm System (NPGS). An assessment of the level of genetic diversity in cultivated pawpaw would assist in development of the future germplasm repository collection strategies for cultivar improvement. The objectives of this study were to identify intersimple sequence repeat (ISSR) markers that segregate in a simple Mendelian fashion and to use these markers to assess genetic diversity in 19 pawpaw cultivars. Leaf samples from the 34 progeny of controlled crosses (1-7-1 × 2-54 and reciprocal) and the parents were collected, DNA was extracted, and subjected to the ISSR methodology using the University of British Columbia microsatellite primer set #9. Seven primers yielded 11 Mendelian markers with either a 3:1 or 1:1 ratio that was confirmed by chi-square analysis. Analysis of genetic diversity using 10 of the ISSR markers from 19 pawpaw cultivars revealed a moderate to high level of genetic diversity, with a percent polymorphic loci P = 80 and an expected heterozygosity He = 0.358. These diversity values are higher than those reported for cultivated pawpaw using isozyme or randomly amplified polymorphic DNA (RAPD) markers, indicating that the ISSR marker methodolgy has a higher level of discrimination in evaluating genetic diversity in pawpaw and/or pawpaw has greater levels of genetic diversity than previously found.

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