Characterization and analysis of simple sequence repeat (SSR) loci in seashore paspalum (Paspalum vaginatum Swartz)

1995 ◽  
Vol 91 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Z.-W. Liu ◽  
R. L. Jarret ◽  
S. Kresovich ◽  
R. R. Duncan
Author(s):  
Júlia Halász ◽  
Noémi Makovics-Zsohár ◽  
Ferenc Szőke ◽  
Sezai Ercisli ◽  
Attila Hegedűs

AbstractPolyploid Prunus spinosa (2n = 4 ×) and P. domestica subsp. insititia (2n = 6 ×) represent enormous genetic potential in Central Europe, which can be exploited in breeding programs. In Hungary, 16 cultivar candidates and a recognized cultivar ‘Zempléni’ were selected from wild-growing populations including ten P. spinosa, four P. domestica subsp. insititia and three P. spinosa × P. domestica hybrids (2n = 5 ×) were also created. Genotyping in eleven simple sequence repeat (SSR) loci and the multiallelic S-locus was used to characterize genetic variability and achieve a reliable identification of tested accessions. Nine SSR loci proved to be polymorphic and eight of those were highly informative (PIC values ˃ 0.7). A total of 129 SSR alleles were identified, which means 14.3 average allele number per locus and all accessions but two clones could be discriminated based on unique SSR fingerprints. A total of 23 S-RNase alleles were identified and the complete and partial S-genotype was determined for 10 and 7 accessions, respectively. The DNA sequence was determined for a total of 17 fragments representing 11 S-RNase alleles. ‘Zempléni’ was confirmed to be self-compatible carrying at least one non-functional S-RNase allele (SJ). Our results indicate that the S-allele pools of wild-growing P. spinosa and P. domestica subsp. insititia are overlapping in Hungary. Phylogenetic and principal component analyses confirmed the high level of diversity and genetic differentiation present within the analysed accessions and indicated putative ancestor–descendant relationships. Our data confirm that S-locus genotyping is suitable for diversity studies in polyploid Prunus species but non-related accessions sharing common S-alleles may distort phylogenetic inferences.


2011 ◽  
Vol 136 (2) ◽  
pp. 116-128 ◽  
Author(s):  
Xinwang Wang ◽  
Phillip A. Wadl ◽  
Cecil Pounders ◽  
Robert N. Trigiano ◽  
Raul I. Cabrera ◽  
...  

Genetic diversity was estimated for 51 Lagerstroemia indica L. cultivars, five Lagerstroemia fauriei Koehne cultivars, and 37 interspecific hybrids using 78 simple sequence repeat (SSR) markers. SSR loci were highly variable among the cultivars, detecting an average of 6.6 alleles (amplicons) per locus. Each locus detected 13.6 genotypes on average. Cluster analysis identified three main groups that consisted of individual cultivars from L. indica, L. fauriei, and their interspecific hybrids. However, only 18.1% of the overall variation was the result of differences between these groups, which may be attributable to pedigree-based breeding strategies that use current cultivars as parents for future selections. Clustering within each group generally reflected breeding pedigrees but was not supported by bootstrap replicates. Low statistical support was likely the result of low genetic diversity estimates, which indicated that only 25.5% of the total allele size variation was attributable to differences between the species L. indica and L. fauriei. Most allele size variation, or 74.5%, was common to L. indica and L. fauriei. Thus, introgression of other Lagestroemia species such as Lagestroemia limii Merr. (L. chekiangensis Cheng), Lagestroemia speciosa (L.) Pers., and Lagestroemia subcostata Koehne may significantly expand crapemyrtle breeding programs. This study verified relationships between existing cultivars and identified potentially untapped sources of germplasm.


PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0127812 ◽  
Author(s):  
Jing Xiao ◽  
Jin Zhao ◽  
Mengjun Liu ◽  
Ping Liu ◽  
Li Dai ◽  
...  

Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 628-633 ◽  
Author(s):  
J. E. Bowers ◽  
G. S. Dangl ◽  
R. Vignani ◽  
C. P. Meredith

Four new simple sequence repeat (SSR) loci (designated VVMD5, VVMD6, VVMD7, and VVMD8) were characterized in grape and analyzed by silver staining in 77 cultivars of Vitis vinifera. Amplification products ranged in size from 141 to 263 base pairs (bp). The number of alleles observed per locus ranged from 5 to 11 and the number of diploid genotypes per locus ranged from 13 to 27. At each locus at least 75% of the cultivars were heterozygous. Alleles differing in length by only 1 bp could be distinguished by silver staining, and size estimates were within 1 or 2 bp, depending on the locus, of those obtained by fluorescence detection at previously reported loci. Allele frequencies were generally similar in wine grapes and table grapes, with some exceptions. Some alleles were found only in one of the two groups of cultivars. All 77 cultivars were distinguished by the four loci with the exception of four wine grapes considered to be somatic variants of the same cultivar, 'Pinot noir', 'Pinot gris', 'Pinot blanc', and 'Meunier'; two table grapes that are known to be synonymous, 'Keshmesh' and 'Thompson Seedless'; and three table grapes, 'Dattier', 'Rhazaki Arhanon', and 'Markandi', the first two of which have been suggested to be synonymous. Although the high polymorphism at grape SSR loci suggests that very few loci would theoretically be needed to separate all cultivars, the economic and legal significance of grape variety identification requires the increased resolution that can be provided by a larger number of loci. The ease with which SSR markers and data can be shared internationally should encourage their broad use, which will in turn increase the power of these markers for both identification and genetic analysis of grape. Key words : grape, Vitis, microsatellite, simple sequence repeat, DNA typing, identification.


Genome ◽  
2000 ◽  
Vol 43 (2) ◽  
pp. 293-297 ◽  
Author(s):  
Muhammad H Rahman ◽  
S Dayanandan ◽  
Om P Rajora

Markers for eight new microsatellite DNA or simple sequence repeat (SSR) loci were developed and characterized in trembling aspen (Populus tremuloides) from a partial genomic library. Informativeness of these microsatellite DNA markers was examined by determining polymorphisms in 38 P. tremuloides individuals. Inheritance of selected markers was tested in progenies of controlled crosses. Six characterized SSR loci were of dinucleotide repeats (two perfect and four imperfect), and one each of trinucleotide and tetranucleotide repeats. The monomorphic SSR locus (PTR15) was of a compound imperfect dinucleotide repeat. The primers of one highly polymorphic SSR locus (PTR7) amplified two loci, and alleles could not be assigned to a specific locus. At the other six polymorphic loci, 25 alleles were detected in 38 P. tremuloides individuals; the number of alleles ranged from 2 to 7, with an average of 4.2 alleles per locus, and the observed heterozygosity ranged from 0.05 to 0.61, with an average of 0.36 per locus. The two perfect dinucleotide and one trinucleotide microsatellite DNA loci were the most informative. Microsatellite DNA variants of four SSR loci characterized previously followed a single-locus Mendelian inheritance pattern, whereas those of PTR7 from the present study showed a two-locus Mendelian inheritance pattern in controlled crosses. The microsatellite DNA markers developed and reported here could be used for assisting various genetic, breeding, biotechnology, genome mapping, conservation, and sustainable forest management programs in poplars. Key words: poplar, microsatellites, genetic mapping, simple sequence repeat (SSR) markers, DNA fingerprinting.


2005 ◽  
Vol 71 (8) ◽  
pp. 4888-4892 ◽  
Author(s):  
Hong Lin ◽  
Edwin L. Civerolo ◽  
Rong Hu ◽  
Samuel Barros ◽  
Marta Francis ◽  
...  

ABSTRACT A genome-wide search was performed to identify simple sequence repeat (SSR) loci among the available sequence databases from four strains of Xylella fastidiosa (strains causing Pierce's disease, citrus variegated chlorosis, almond leaf scorch, and oleander leaf scorch). Thirty-four SSR loci were selected for SSR primer design and were validated in PCR experiments. These multilocus SSR primers, distributed across the X. fastidiosa genome, clearly differentiated and clustered X. fastidiosa strains collected from grape, almond, citrus, and oleander. They are well suited for differentiating strains and studying X. fastidiosa epidemiology and population genetics.


Genome ◽  
2003 ◽  
Vol 46 (2) ◽  
pp. 277-290 ◽  
Author(s):  
Eline van Zijll de Jong ◽  
Kathryn M Guthridge ◽  
German C Spangenberg ◽  
John W Forster

Fungal endophytes of the genus Neotyphodium are common in temperate pasture grass species and confer both beneficial and deleterious agronomic characteristics to their hosts. The aim of this study was to develop molecular markers based on simple sequence repeat (SSR) loci for the identification and assessment of genetic diversity among Neotyphodium endophytes in grasses. Expressed sequence tags (ESTs) from both Neptyphodium coenophialum and Neotyphodium lolii were examined, and unique SSR loci were identified in 9.7% of the N. coenophialum sequences and 6.3% of the N. lolii sequences. A variety of SSRs were present, although perfect trinucleotide repeat arrays were the most common. Primers were designed to 50 SSR loci from N. coenophialum and 57 SSR loci from N. lolii and were evaluated using 20 Neotyphodium and Epichloë isolates. A high proportion of the N. coenophialum and N. lolii primers produced amplification products from the majority of isolates and most of these primers detected genetic variation. SSR markers from both N. coenophialum and N. lolii detected high levels of polymorphism between Neotyphodium and Epichloë species, and low levels of polymorphism within N. coenophialum and N. lolii. SSR markers may be used in appropriate combinations to discriminate between species. Comparison with amplified fragment length polymorphism (AFLP) data demonstrated that the SSR markers were informative for the assessment of genetic variation within and between endophyte species. These markers may be used to identify endophyte taxa and to evaluate intraspecific population diversity, which may be correlated with variation for endophyte-derived agronomic traits.Key words: Neotyphodium, simple sequence repeats, expressed sequence tags, amplified fragment length polymorphism, genetic diversity.


Genetics ◽  
1992 ◽  
Vol 132 (4) ◽  
pp. 1131-1139 ◽  
Author(s):  
M S Akkaya ◽  
A A Bhagwat ◽  
P B Cregan

Abstract The objective of this work was to ascertain the presence and degree of simple sequence repeat (SSR) DNA length polymorphism in the soybean [Glycine max (L.) Merr.]. A search of GenBank revealed no (CA)n or (GT)n SSRs with n greater than 8 in soybean. In contrast, 5 (AT)n and 1 (ATT)n SSRs with n ranging from 14 to 27 were detected. Polymerase chain reaction (PCR) primers to regions flanking the six SSR loci were used in PCR amplification of DNA from 43 homozygous soybean genotypes. At three loci, amplification produced one PCR product per genotype and revealed 6, 7 and 8 product length variants (alleles) at the three loci, respectively. F1 hybrids between parents carrying different alleles produced two PCR products identical to the two parents. Codominant segregation of alleles among F2 progeny was demonstrated at each locus. A soybean DNA library was screened for the presence of (CA/GT)n SSRs. Sequencing of positive clones revealed that the longest such SSR was (CA)9. Thus, (CA)n SSRs with n of 15 or more are apparently much less common in soybean than in the human genome. In contrast to humans, (CA)n SSRs will probably not provide an abundant source of genetic markers in soybean. However, the apparent abundance of long (AT)n sequences should allow this SSR to serve as a source of highly polymorphic genetic markers in soybean.


2007 ◽  
Vol 132 (3) ◽  
pp. 341-351 ◽  
Author(s):  
Sandra M. Reed ◽  
Timothy A. Rinehart

Genetic diversity studies using 39 simple-sequence repeat (SSR) markers were carried out with 114 taxa of Hydrangea macrophylla (Thunb.) Ser., including 87 H. macrophylla ssp. macrophylla cultivars and 20 members of H. macrophylla ssp. serrata (Thunb.) Makino. The SSR loci were highly variable among the taxa, producing a mean of 8.26 alleles per locus. Overall allelic richness was relatively high at 5.12 alleles per locus. H. macrophylla ssp. serrata contained nearly twice the allelic diversity of H. macrophylla ssp. macrophylla. The majority of genetic diversity was found to reside within the subspecies, with only 12% of the total genetic diversity observed occurring between subspecies. Although the elevation of H. macrophylla ssp. serrata to species level has recently been recommended by several hydrangea authorities, these data support the subspecies designation. Four cultivars (Preziosa, Pink Beauty, Tokyo Delight, and Blue Deckle) appeared to be hybrids between the two subspecies. Genetic similarities were found among five remontant cultivars (Bailmer, Oak Hill, David Ramsey, Decatur Blue, and Penny Mac) and several nonremontant cultivars, including General Vicomtesse de Vibraye, Nikko Blue, All Summer Beauty, and La France. No close genetic relationship was found between the remontant cultivar Early Sensation and other remontant cultivars. Genetic similarities were found among variegated and double-flower cultivars. Within H. macrophylla ssp. macrophylla, cultivars with mophead inflorescences clustered separately from most lacecap cultivars. This indicates the cultivars with lacecap inflorescences that were among some of the earliest introductions to Europe were not widely used in the breeding of mophead forms. Some presumed synonyms were found to be valid (‘Preziosa’ and ‘Pink Beauty’, ‘Rosalba’ and ‘Benigaku’, ‘Geoffrey Chadbund’ and ‘Mowe’), whereas others were not (‘Harlequin’ and ‘Monrey’, ‘Nigra’ and ‘Mandschurica’). This study identified potentially unexploited sources of germplasm within H. macrophylla and relationships between existing cultivars of this popular shrub. This information should be of value when selecting parents for breeding programs.


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