scholarly journals Development and characterization of EST-SSRs for Muscidae (Diptera) and their cross-genera transferability

2019 ◽  
Vol 28 (3) ◽  
pp. 148-156
Author(s):  
Dan-Dan Wang ◽  
Dong-Xia Yang

EST-SSR (Expressed Sequence Tag-Simple Sequence Repeat)markers were developed and used to examine genetic diversity of species assemblages of ten genera of Muscidae (Diptera), and specifically the genetic diversity of Phaonia Robineau species, from ten regions in China. 18 EST-SSR markers with high polymorphism and clear bands were screened out from 216 tested markers, with 219 alleles in total (95–280 bp) with an average of 6.1 alleles per locus. In various regions in China such as Tibet, Sichuan, and Yunnan, Muscidae species assemblages exhibited rich genetic diversity, with the polymorphism information content (PIC) values ranging from 0.831 to 0.934, while Hainan region showed a relatively low genetic diversity (PIC = 0.511). Low gene flow (Nm = 0.842) was found among the regions, and the average genetic differentiation coefficient (Fst) was 0.238, indicating a high degree of genetic differentiation among the ten surveyed assemblages. Accordingly, the ten genera of Muscidae exhibited high genetic diversity and genetic differentiation.

Botany ◽  
2010 ◽  
Vol 88 (5) ◽  
pp. 537-543 ◽  
Author(s):  
Yong-Bi Fu ◽  
Gregory W. Peterson

One major challenge in genetic and evolutionary studies of wild flax species is the lack of informative molecular markers. A set of 100 informative expressed sequence tag-derived simple sequence repeat (EST-SSR) primer pairs developed in cultivated flax ( Linum usitatissimum L.) were characterized on 35 Linum accessions representing 17 Linum species for their transferability to other Linum species. Ninety-nine primer pairs displayed scorable polymorphisms across 35 Linum samples and generated 627 bands likely from 121 loci. About 50% of the detected bands occurred only in three or fewer samples. A total of 393 bands, likely from 116 loci, were detected by 97 primer pairs in Linum bienne Mill. samples, but only up to 60 bands, likely from up to 39 loci, were revealed by 6 to 37 primer pairs in the samples of the other 15 Linum species. The L. bienne samples displayed 23.7% more EST-SSR variation than the L. usitatissimum samples. These characterized EST-SSR markers should be useful for future genetic diversity and evolutionary studies of Linum species, particularly for the progenitor of cultivated flax.


BMC Genetics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Cun Chen ◽  
Yanguang Chu ◽  
Changjun Ding ◽  
Xiaohua Su ◽  
Qinjun Huang

Abstract Background Black cottonwood (Populus deltoides) is one of the keystone forest tree species, and has become the main breeding parents in poplar hybrid breeding. However, the genetic diversity and population structure of the introduced resources are not fully understood. Results In the present study, five loci containing null alleles were excluded and 15 pairs of SSR (simple sequence repeat) primers were used to analyze the genetic diversity and population structure of 384 individuals from six provenances (Missouri, Iowa, Washington, Louisiana, and Tennessee (USA), and Quebec in Canada) of P. deltoides. Ultimately, 108 alleles (Na) were detected; the expected heterozygosity (He) per locus ranged from 0.070 to 0.905, and the average polymorphic information content (PIC) was 0.535. The provenance ‘Was’ had a relatively low genetic diversity, while ‘Que’, ‘Lou’, and ‘Ten’ provenances had high genetic diversity, with Shannon’s information index (I) above 1.0. The mean coefficient of genetic differentiation (Fst) and gene flow (Nm) were 0.129 and 1.931, respectively. Analysis of molecular variance (AMOVA) showed that 84.88% of the genetic variation originated from individuals. Based on principal coordinate analysis (PCoA) and STRUCTURE cluster analysis, individuals distributed in the Mississippi River Basin were roughly classified as one group, while those distributed in the St. Lawrence River Basin and Columbia River Basin were classified as another group. The cluster analysis based on the population level showed that provenance ‘Iow’ had a small gene flow and high degree of genetic differentiation compared with the other provenances, and was classified into one group. There was a significant relationship between genetic distance and geographical distance. Conclusions P. deltoides resources have high genetic diversity and there is a moderate level of genetic differentiation among provenances. Geographical isolation and natural conditions may be the main factors causing genetic differences among individuals. Individuals reflecting population genetic information can be selected to build a core germplasm bank. Meanwhile, the results could provide theoretical support for the scientific management and efficient utilization of P. deltoides genetic resources, and promote the development of molecular marker-assisted breeding of poplar.


Author(s):  
Romeo Di Pietro ◽  
Antonio Luca Conte ◽  
Piera Di Marzio ◽  
Paola Fortini ◽  
Emmanuele Farris ◽  
...  

AbstractMolecular diversity analysis of deciduous pubescent oaks was conducted for populations from Calabria, Sicily and Sardinia. The aims of this study were twofold. First, to provide data on the genetic diversity of pubescent oaks from an understudied area which currently exhibits one of the highest concentrations of pubescent oak species in Europe. Second, to verify if these groups of oaks are genetically distinct and if their identification is in accordance with the current taxonomic classification. Molecular analyses of leaf material of 480 trees from seventeen populations belonging to putatively different pubescent oak species (Quercus amplifolia, Q. congesta, Q. dalechampii, Q. ichnusae, Q. leptobalanos, Q. virgiliana) were performed. Twelve gene-based Expressed Sequence Tag-Simple Sequence Repeat markers were selected, and genetic diversity and differentiation were calculated. The results showed relatively high values of allelic richness, heterozygosity and number of private alleles for the populations investigated. A weak but positive correlation between geographical and genetic distance was detected. Genetic assignment (STRUCTURE) and principle coordinate analyses exhibited a weak separation into two genetic groups which, however, did not correspond to the taxonomic, chorological and ecological features of the populations investigated. Sardinian populations formed one group which was separated from the Calabrian and Sicilian populations. In light of the results obtained, the taxonomic classification for the pubescent white oaks currently reported in the major Italian floras and checklists for the study area was not confirmed by molecular analyses.


Genome ◽  
2011 ◽  
Vol 54 (12) ◽  
pp. 1016-1028 ◽  
Author(s):  
Amaresh Chandra ◽  
K.K. Tiwari ◽  
D. Nagaich ◽  
N. Dubey ◽  
S. Kumar ◽  
...  

A limited number of functional molecular markers has slowed the desired genetic improvement of Stylosanthes species. Hence, in an attempt to develop simple sequence repeat (SSR) markers, genomic libraries from Stylosanthes seabrana B.L. Maass & ’t Mannetje (2n = 2x = 20) using 5′ anchored degenerate microsatellite primers were constructed. Of the 76 new microsatellites, 21 functional primer pairs were designed. Because of the small number of primer pairs designed, 428 expressed sequence tag (EST) sequences from seven Stylosanthes species were also examined for SSR detection. Approximately 10% of sequences delivered functional primer pairs, and after redundancy elimination, 57 microsatellite repeats were selected. Tetranucleotides followed by trinucleotides were the major repeated sequences in Stylosanthes ESTs. In total, a robust set of 21 genomic–SSR (gSSR) and 20 EST–SSR (eSSR) markers were developed. These markers were analyzed for intraspecific diversity within 20 S. seabrana accessions and for their cross-species transferability. Mean expected (He) and observed (Ho) heterozygosity values with gSSR markers were 0.64 and 0.372, respectively, whereas with eSSR markers these were 0.297 and 0.214, respectively. Dendrograms having moderate bootstrap value (23%–94%) were able to distinguish all accessions of S. seabrana with gSSR markers, whereas eSSR markers showed 100% similarities between few accessions. The set of 21 gSSRs, from S. seabrana, and 20 eSSRs, from selected Stylosanthes species, with their high cross-species transferability (45% with gSSRs, 86% with eSSRs) will facilitate genetic improvement of Stylosanthes species globally.


2021 ◽  
Vol 12 ◽  
Author(s):  
Haftom Brhane ◽  
Teklehaimanot Haileselassie ◽  
Kassahun Tesfaye ◽  
Cecilia Hammenhag ◽  
Rodomiro Ortiz ◽  
...  

Finger millet (Eleusine coracana (L.) Geartn.) is a self-pollinating amphidiploid crop cultivated with minimal input for food and feed, as well as a source of income for small-scale farmers. To efficiently assess its genetic diversity for conservation and use in breeding programs, polymorphic DNA markers that represent its complex tetraploid genome have to be developed and used. In this study, 13 new expressed sequence tag-derived simple sequence repeat (EST-SSR) markers were developed based on publicly available finger millet ESTs. Using 10 polymorphic SSR markers (3 genomic and 7 novel EST-derived), the genetic diversity of 55 landrace accessions and 5 cultivars of finger millet representing its major growing areas in Ethiopia was assessed. In total, 26 alleles were detected across the 10 loci, and the average observed number of alleles per locus was 5.6. The polymorphic information content (PIC) of the loci ranged from 0.045 (Elco-48) to 0.71 (UGEP-66). The level of genetic diversity did not differ much between the accessions with the mean gene diversity estimates ranging only from 0.44 (accession 216054) to 0.68 (accession 237443). Similarly, a narrow range of variation was recorded at the level of regional states ranging from 0.54 (Oromia) to 0.59 (Amhara and Tigray). Interestingly, the average gene diversity of the landrace accessions (0.57) was similar to that of the cultivars (0.58). The analysis of molecular variance (AMOVA) revealed significant genetic variation both within and among accessions. The variation among the accessions accounted for 18.8% of the total variation (FST = 0.19; P < 0.001). Similarly, significant genetic variation was obtained among the geographic regions, accounting for 6.9% of the total variation (P < 0.001). The results of the cluster, principal coordinate, and population structure analyses suggest a poor correlation between the genetic makeups of finger millet landrace populations and their geographic regions of origin, which in turn suggests strong gene flow between populations within and across geographic regions. This study contributed novel EST-SSR markers for their various applications, and those that were monomorphic should be tested in more diverse finger millet genetic resources.


Author(s):  
Narendra Singh Rajpoot ◽  
M. K. Tripathi ◽  
Sushma Tiwari ◽  
R. S. Tomar ◽  
V. S. Kandalkar

The genus Brassica is one of the most important oil seed crops in India with high degree of genetic diversity. In present study, genetic diversity was studied in forty germplasm lines and eight cultivars of Indian mustard using morphological traits and SSR markers. Morphological characters were taken for days to 50% flowering, days to maturity, plant height (cm), length of main raceme (cm), number of primary branches/plant, number of secondary branches/plant, number of silique per plant, number of seeds per silique, 1000 seed weight (g) and seed yield per plant (g). Total 50 SSR markers were used for characterization of these lines, out of which 7 SSR markers were highly polymorphic between all the germplasms of mustard. An UPGMA phonogram was constructed for all 48 Germplasms and the similarity coefficient ranged from 0.00 to 0.91. Number of alleles ranged from 3 to 4, genetic diversity ranged from 71% to 65% with average value of 67%, heterozygosity raged from 20 to 10% with average of 12% and PIC value for markers ranged from 0.65 to 0.59 with mean PIC value 0.61. All seven SSR primers showed PIC value above 0.5 (50%) indicating high genetic diversity in the studied plant material.


2019 ◽  
Author(s):  
Cun Chen ◽  
Yanguang Chu ◽  
Changjun Ding ◽  
Xiaohua Su ◽  
Qinjun Huang

Abstract Background: Black cottonwood (Populus deltoides) is one of the keystone forest tree species, and has become the main breeding parents in poplar hybrid breeding. However, the genetic diversity and population structure of the introduced resources are not fully understood. Results: In the present study, five loci containing null alleles were excluded and 15 pairs of SSR (simple sequence repeat) primers were used to analyze the genetic diversity and population structure of 384 individuals from six provenances of P. deltoides. Ultimately, 108 alleles (Na) were detected; the expected heterozygosity (He) ranged from 0.070 to 0.905, and the average locus polymorphic information content (PIC) was 0.5354. The provenance ‘Was’ had the lowest genetic diversity, while ‘Que’, ‘Lou’, and ‘Ten’ provenances had high genetic diversity, with Shannon's information index (I) above 1.0. The mean coefficient of genetic differentiation (Fst) and gene flow (Nm) were 0.129 and 1.931 respectively. Analysis of molecular variance (AMOVA) showed that 84.88% of the genetic variation originated from individuals. Based on principal coordinate analysis (PCoA) and STRUCTURE cluster analysis, clones distributed in Mississippi River Basin were roughly classified as one group, while those distributed in the St. Lawrence River Basin and Columbia River Basin were classified as another group. The cluster analysis based on the population level showed that provenance ‘Iow’ had a smaller gene flow and higher degree of genetic differentiation compared with the other provenances, and was classified into one group. There was no significant relationship between genetic distance and geographical distance. Conclusions: P. deltoides resources have high genetic diversity and there is a moderate level of genetic differentiation among provenances. Geographical isolation and natural conditions may be the main factors causing genetic differences among individuals; however, the genetic variation among provenances has no clear correlation with their geographical locations. Clones reflecting population genetic information can be selected to build a core resource bank, which could provide effective protection and promote the scientific utilization of the P. deltoids resource, laying a solid foundation for poplar breeding.


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