scholarly journals Frequency of Polyploids of Solanum tuberosum Dihaploids in 2X × 2X Crosses

2021 ◽  
pp. 76-80
Author(s):  
Susan A. Otieno ◽  
Joseph Coombs ◽  
David S. Douches
Keyword(s):  
Single Nucleotide Polymorphism ◽  
High Frequency ◽  
2N Pollen ◽  
Sexual Polyploidization ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Breeding Programs ◽  
2N Eggs ◽  
Bilateral Sexual Polyploidization ◽  
Tetraploid Progeny

When breeding diploid potatoes, tetraploid progeny can result from the union of 2n eggs and 2n pollen in 2x-2x crosses. Thirty-three crosses were made to examine tetraploid progeny frequency in 2x-2x crosses. All crosses were between S. tuberosum dihaploids and diploid self-compatible donors, M6 and DRH S6-10-4P17. Using chloroplast counting for ploidy determination, the frequency of tetraploid progeny was as high as 45% in one of the 33 crosses. Based upon single nucleotide polymorphism (SNP) genotyping, the tetraploid progeny were attributed to bilateral sexual polyploidization (BSP), which is caused by the union of 2n egg and 2n pollen. Dihaploids were identified that produce lower frequencies of 2n eggs. The results of this study suggest that S. tuberosum dihaploids with a high frequency of 2n eggs should be avoided in 2x - 2x crosses for diploid breeding programs.

Bilateral sexual tetraploidization in red clover

1985 ◽  
Vol 27 (1) ◽  
pp. 64-68 ◽  
Author(s):  
W. A. Parrott ◽  
R. R. Smith ◽  
M. M. Smith
Keyword(s):  
Egg Production ◽  
Trifolium Pratense ◽  
2N Gametes ◽  
Red Clover ◽  
Female Plant ◽  
2N Pollen ◽  
Sexual Polyploidization ◽  
2N Eggs ◽  
Trifolium Pratense L ◽  
Bilateral Sexual Polyploidization

Twenty-four diploid red clover (Trifolium pratense L.) plants, from the cultivars 'Arlington', 'Florex', and 'Redman', and C760, a Wisconsin synthetic, were tested for 2n egg production by crossing them with tetraploid plants. Four plants were identified and selected as 2n egg producers. These plants were then crossed with a known producer of 2n pollen in an attempt to obtain tetraploid plants through bilateral sexual polyploidization. Thirteen percent of the seed obtained in one of the 2x–2x crosses were tetraploid. The female plant produced an estimated 0.14 2n eggs per 1000 flowers in the cross. In a second experiment, bilateral sexual polyploidization was attempted, using 14 plants which had not been previously tested for 2n egg production. Two of these plants produced one and two tetraploids each, representing 2n egg frequencies of 3.33 and 5.00 2n eggs per 1000 flowers, respectively. It seems likely that it will be possible to use bilateral sexual polyploidization to tetraploidize red clover germplasm in the future.Key words: tetraploid red clover, Trifolium pratense. 2n gametes.

scholarly journals High frequency of the PNPLA3 rs738409 [G] single-nucleotide polymorphism in Hmong individuals as a potential basis for a predisposition to chronic liver disease

Cancer ◽  
2018 ◽  
Vol 124 ◽  
pp. 1583-1589 ◽  
Author(s):  
Clifford G. Tepper ◽  
Julie H. T. Dang ◽  
Susan L. Stewart ◽  
Dao M. Fang ◽  
Kimberly A. Wong ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Liver Disease ◽  
Chronic Liver Disease ◽  
High Frequency ◽  
Chronic Liver ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Potential Basis

scholarly journals Molecular Mapping of the Major Resistance Quantitative Trait Locus qHS2.09 with Simple Sequence Repeat and Single Nucleotide Polymorphism Markers in Maize

2012 ◽  
Vol 102 (7) ◽  
pp. 692-699 ◽  
Author(s):  
Jianfeng Weng ◽  
Xianjun Liu ◽  
Zhenhua Wang ◽  
Jianjun Wang ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Quantitative Trait Locus ◽  
Single Nucleotide Polymorphism ◽  
Quantitative Trait ◽  
Nucleotide Polymorphism ◽  
Head Smut ◽  
Maize Breeding ◽  
Single Nucleotide ◽  
Breeding Programs ◽  
Trait Locus ◽  
Major Qtl

The major quantitative trait locus (QTL) qHS2.09 plays an important role in resistance to head smut during maize breeding and production. In this study, a near-isogenic line (NIL), L34, which harbors the major QTL qHS2.09 in bin 2.09, was developed using a resistant donor ‘Mo17’ in a susceptible genetic background ‘Huangzao4’. Using 18,683 genome-wide polymorphic loci, this major QTL was finely mapped into an interval of ≈1.10 Mb, flanked by single nucleotide polymorphism (SNP) markers PZE-102187307 and PZE-102188421. Moreover, the favorable allele from ‘Mo17’ for SNP PZE-102187611 in this interval that was most significantly associated with resistance to head smut (P = 1.88 E-10) and accounted for 39.7 to 44.4% of the phenotypic variance in an association panel consisting of 80 inbred lines. With combined linkage and association mapping, this major QTL was finally located between SNP PZE-102187486 and PZE-102188421 with an interval of ≈1.00 Mb. Based on the pedigrees of ‘Mo17’ and its derivatives widely used in temperate maize breeding programs, the favorable haplotype from ‘Mo17’ is shown to be the main source of resistance to head smut in these lines. Therefore, the SNPs closely linked to the major QTL qHS2.09, detected in both linkage and association mapping, and could be useful for marker-assisted selection in maize breeding programs.

scholarly journals Infection with different strains of SARS-COV-2 in patients with COVID-19

2020 ◽  
Vol 72 (4) ◽  
pp. 575-585 ◽  
Author(s):  
Hayder Hashim ◽  
Mudher Mohammed ◽  
Mazin Mousa ◽  
Hadeer Abdulameer ◽  
Alaa Alhassnawi ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphism ◽  
High Frequency ◽  
Biological Diversity ◽  
Viral Infections ◽  
Phylogenetic Analyses ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Single Strain ◽  
Different Strains ◽  
Multiple Strains

The biological diversity of SARS-CoV-2 was assessed by investigating the genetic variations of the spike glycoprotein of patients with COVID-19 in Iraq. Sequencing identified fifteen novel nucleic acid variations with a variety of distributions within the investigated samples. The electropherograms of all identified variations showed obvious co-infections with two different viral strains per sample. Most samples exhibited three nonsense single nucleotide polymorphism (SNPs), p.301Cdel, p.380Ydel and p.436del, which yielded three truncated spike glycoproteins, respectively. Network and phylogenetic analyses indicated that all viral infections were derived from multiple viral origins. Results inferred from the specific clade-based tree showed that some viral strains were derived from European G-clade sequences. Our data demonstrated the absence of single-strain infection among all investigated samples in the studied area, which entails a higher risk of SARS-CoV-2 in this country. The identified high frequency of truncated spike proteins suggests that defective SARS-CoV-2 depend on helper strains possessing intact spikes during infection. Alternatively, another putative ACE2-independent route of viral infection is suggested. To the best of our knowledge, this is the first report to describe co-infection with multiple strains of SARS-CoV-2 in patients with COVID-19.

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