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result(s) for
"Pacheco, Igor"
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Genetic dissection of fruit weight and size in an F2 peach (Prunus persica (L.) Batsch) progeny
by
Bianco, Luca
,
da Silva Linge, Cássia
,
Bassi, Daniele
in
Arrays
,
Biomedical and Life Sciences
,
Biotechnology
2015
Fruit weight is a quantitative trait influenced by the combined action of several genes and environmental factors. Knowledge of the quantitative trait loci (QTLs) associated with fruit weight and size is a priority to support breeding programmes in peach (
Prunus persica
(L.) Batsch) because of commercial interest in larger fruits. To this end, we built a genetic map of an F
2
progeny of 117 individuals from the cross PI91459 (‘NJ Weeping’) × ‘Bounty’ using a single nucleotide polymorphism (SNP) genotyping array for peach (9K SNP array v1). Data for fruit weight, height, width, and depth were recorded for the progeny and both parents over 2 years (2011, 2012). Correlations between the traits fruit weight and size were positive and significant for both years. A SNP map was constructed comprising 1,148 markers distributed over eight linkage groups. The map spans 536.6 cM with an average distance between markers of 0.52 cM, covering 93.6 % of the physical length of the peach genome, thus representing an ideal basis for QTL mapping. QTL analysis led to the identification of a total of 28 QTLs for the considered traits, eleven of which remained stable in both years. We also observed clusters of QTLs, some of which were mapped for the first time, while others correspond to loci previously identified in different progenies and following different approaches.
Journal Article
A Unique Mutation in a MYB Gene Cosegregates with the Nectarine Phenotype in Peach
by
Dettori, Maria Teresa
,
Gazza, Laura
,
Scalabrin, Simone
in
Agriculture
,
Biology
,
Breeding - methods
2014
Nectarines play a key role in peach industry; the fuzzless skin has implications for consumer acceptance. The peach/nectarine (G/g) trait was described as monogenic and previously mapped on chromosome 5. Here, the position of the G locus was delimited within a 1.1 cM interval (635 kb) based on linkage analysis of an F2 progeny from the cross 'Contender' (C, peach) x 'Ambra' (A, nectarine). Careful inspection of the genes annotated in the corresponding genomic sequence (Peach v1.0), coupled with variant discovery, led to the identification of MYB gene PpeMYB25 as a candidate for trichome formation on fruit skin. Analysis of genomic re-sequencing data from five peach/nectarine accessions pointed to the insertion of a LTR retroelement in exon 3 of the PpeMYB25 gene as the cause of the recessive glabrous phenotype. A functional marker (indelG) developed on the LTR insertion cosegregated with the trait in the CxA F2 progeny and was validated on a broad panel of genotypes, including all known putative donors of the nectarine trait. This marker was shown to efficiently discriminate between peach and nectarine plants, indicating that a unique mutational event gave rise to the nectarine trait and providing a useful diagnostic tool for early seedling selection in peach breeding programs.
Journal Article
Weight loss interventions for overweight and obese adolescents: a systematic review
by
Boff, Raquel de Melo
,
de Souza, Lauren Heineck
,
Batista, Igor Pacheco de Azevedo
in
Adolescent
,
Behavior Therapy
,
Body Mass Index
2017
Purpose
To determine what factors contribute to the efficacy of non-drug treatments designed to promote weight loss in overweight and obese adolescents.
Methods
Data sources
Medline/PubMed; Psychinfo; EMBASE; Web of Science (ISI); and Cochrane Central Register of Controlled Trials.
Study selection
Randomized clinical trials of treatments for obesity and overweight in adolescents aged 10–19 years with a minimum duration of 2 months.
Data extraction
115 of the 12,948 publications retrieved met eligibility criteria and 26 were included in the final sample.
Period of extraction
January 2004 to November 2014.
Results
The Delphi list was used to evaluate the methodological quality of the studies (
M
= 5.58, SD = 1.027). There was considerable variability between the interventions, but they were all multifactorial, with components such as nutritional education, physical activity, family support and psychological therapy. The number of contacts with subjects during the course of the intervention was a predictor of treatment efficacy when the groups were compared.
Limitations
This systematic review was limited to trials reported in English and by the lack of methodological rigor and shortcomings in reporting in the studies reviewed.
Conclusions
Multidisciplinary interventions including family support and guided behavior modification appear to be effective methods of reducing BMI in overweight and obese adolescents.
Journal Article
Fine mapping and identification of a candidate gene for a major locus controlling maturity date in peach
2013
Background
Maturity date (MD) is a crucial factor for marketing of fresh fruit, especially those with limited shelf-life such as peach (
Prunus persica
L. Batsch): selection of several cultivars with differing MD would be advantageous to cover and extend the marketing season. Aims of this work were the fine mapping and identification of candidate genes for the major maturity date locus previously identified on peach linkage group 4. To improve genetic resolution of the target locus two F
2
populations derived from the crosses Contender x Ambra (CxA, 306 individuals) and PI91459 (NJ Weeping) x Bounty (WxBy, 103 individuals) were genotyped with the Sequenom and 9K Illumina Peach Chip SNP platforms, respectively.
Results
Recombinant individuals from the WxBy F
2
population allowed the localisation of maturity date locus to a 220 kb region of the peach genome. Among the 25 annotated genes within this interval, functional classification identified ppa007577m and ppa008301m as the most likely candidates, both encoding transcription factors of the NAC (
N
AM/
A
TAF1, 2/
C
UC2) family. Re-sequencing of the four parents and comparison with the reference genome sequence uncovered a deletion of 232 bp in the upstream region of ppa007577m that is homozygous in NJ Weeping and heterozygous in Ambra, Bounty and the WxBy F
1
parent. However, this variation did not segregate in the CxA F
2
population being the CxA F
1
parent homozygous for the reference allele. The second gene was thus examined as a candidate for maturity date. Re-sequencing of ppa008301m, showed an in-frame insertion of 9 bp in the last exon that co-segregated with the maturity date locus in both CxA and WxBy F
2
populations.
Conclusions
Using two different segregating populations, the map position of the maturity date locus was refined from 3.56 Mb to 220 kb. A sequence variant in the NAC gene ppa008301m was shown to co-segregate with the maturity date locus, suggesting this gene as a candidate controlling ripening time in peach. If confirmed on other genetic materials, this variant may be used for marker-assisted breeding of new cultivars with differing maturity date.
Journal Article
Whole-genome analysis of diversity and SNP-major gene association in peach germplasm
by
Dettori, Maria Teresa
,
Nazzicari, Nelson
,
Rossini, Laura
in
Agricultural sciences
,
Biodiversity
,
Bioinformatics
2015
Peach was domesticated in China more than four millennia ago and from there it spread world-wide. Since the middle of the last century, peach breeding programs have been very dynamic generating hundreds of new commercial varieties, however, in most cases such varieties derive from a limited collection of parental lines (founders). This is one reason for the observed low levels of variability of the commercial gene pool, implying that knowledge of the extent and distribution of genetic variability in peach is critical to allow the choice of adequate parents to confer enhanced productivity, adaptation and quality to improved varieties. With this aim we genotyped 1,580 peach accessions (including a few closely related Prunus species) maintained and phenotyped in five germplasm collections (four European and one Chinese) with the International Peach SNP Consortium 9K SNP peach array. The study of population structure revealed the subdivision of the panel in three main populations, one mainly made up of Occidental varieties from breeding programs (POP1OCB), one of Occidental landraces (POP2OCT) and the third of Oriental accessions (POP3OR). Analysis of linkage disequilibrium (LD) identified differential patterns of genome-wide LD blocks in each of the populations. Phenotypic data for seven monogenic traits were integrated in a genome-wide association study (GWAS). The significantly associated SNPs were always in the regions predicted by linkage analysis, forming haplotypes of markers. These diagnostic haplotypes could be used for marker-assisted selection (MAS) in modern breeding program
Journal Article
Detection of Quantitative Trait Loci Controlling the Content of Phenolic Compounds in an Asian Plum (Prunus salicina L.) F1 Population
by
Jiménez-Muñoz, Pablo
,
Gardana, Claudio
,
Sepúlveda-González, Ailynne
in
Anthocyanins
,
antioxidant activity
,
Antioxidants
2021
Consumption of fresh fruit is known to protect against non-communicable diseases due to the fruit's content in compounds with an antioxidant capacity, among them is polyphenols. Asian plums ( Prunus salicina L .) accumulate more than 40 phenolic compounds, with a remarkable diversity in their profiles, depending on the variety and environmental conditions. Although candidate genes have been indicated to control this trait, the loci controlling its phenotypic variation have not yet been defined in this species. The aim of this work was to identify the quantitative trait Loci (QTL) controlling the phenolic compounds content in the Asian plum skin and flesh. Using UHPLC-DAD-Orbitrap-MS, we determined that cyanidin-3-glucoside and cyanidin-3-rutinoside are the main anthocyanins in Asian plums. Other anthocyanins found to a lesser extent were tentatively identified as cyanidin bound to different sugar and procyanidin moieties. Then we phenotyped fruits of 92 and 80 F1 seedlings from the cross < “98.99” × “Angeleno”> (98 Ang) for two harvest seasons. We used HPLC-DAD to quantify single anthocyanin and spectrophotometric techniques to determine the total content of phenols, flavonoids, procyanidins, and antioxidant activity (DPPH and FRAP). To determine the phenotype-genotype association of phenolic compounds content, phenotypic values (adjusted by linear mixed-effects models), genotypic data and linkage maps were analyzed with the multiple QTL model (MQM) approach. We found a total of 21 significant trait-marker associations: 13 QTLs segregating from “98.99” and 8 QTLs from “Angeleno.” From these associations, 8 corresponded to phenolic compound content in the flesh and 13 in the skin. Phenotype variance was explained by the detected loci , ranging from 12.4 to 27.1%. The identified loci are related to the content of cyanidin-3-glucoside (LG4), cyanidin-3-rutinoside (LG4), total flavonoids and procyanidins (LG5 and LG8), and minor anthocyanin compounds (LG3 and LG4). These results will help improve the efficiency of breeding programs for the generation of Asian plum varieties with high phenolic compound content.
Journal Article
Genotyping by Sequencing for SNP-Based Linkage Analysis and Identification of QTLs Linked to Fruit Quality Traits in Japanese Plum (Prunus salicina Lindl.)
2017
Marker-assisted selection (MAS) in stone fruit (
species) breeding is currently difficult to achieve due to the polygenic nature of the most relevant agronomic traits linked to fruit quality. Genotyping by sequencing (GBS), however, provides a large quantity of useful data suitable for fine mapping using Single Nucleotide Polymorphisms (SNPs) from a reference genome. In this study, GBS was used to genotype 272 seedlings of three F1 Japanese plum (
Lindl) progenies derived from crossing \"98-99\" (as a common female parent) with \"Angeleno,\" \"September King,\" and \"September Queen\" as male parents. Raw sequences were aligned to the Peach genome v1, and 42,909 filtered SNPs were obtained after sequence alignment. In addition, 153 seedlings from the \"98-99\" × \"Angeleno\" cross were used to develop a genetic map for each parent. A total of 981 SNPs were mapped (479 for \"98-99\" and 502 for \"Angeleno\"), covering a genetic distance of 688.8 and 647.03 cM, respectively. Fifty five seedlings from this progeny were phenotyped for different fruit quality traits including ripening time, fruit weight, fruit shape, chlorophyll index, skin color, flesh color, over color, firmness, and soluble solids content in the years 2015 and 2016. Linkage-based QTL analysis allowed the identification of genomic regions significantly associated with ripening time (LG4 of both parents and both phenotyping years), fruit skin color (LG3 and LG4 of both parents and both years), chlorophyll degradation index (LG3 of both parents in 2015) and fruit weight (LG7 of both parents in 2016). These results represent a promising situation for GBS in the identification of SNP variants associated to fruit quality traits, potentially applicable in breeding programs through MAS, in a highly heterozygous crop species such as Japanese plum.
Journal Article
Two Consecutive Days of Low-Dose Methotrexate Toxicity: A Diagnostic Challenge
2025
Methotrexate is an immunosuppressive medication commonly used to treat rheumatological disorders, primarily by inhibiting the folic acid cycle, with dose-dependent toxicity affecting multiple organ systems. A 54-year-old woman with a history of rheumatoid arthritis (RA), previously treated with methotrexate but later switched to leflunomide, etanercept, and prednisone, presented to the emergency department due to abnormal lab results. After running out of leflunomide and experiencing increased joint pain, she resumed methotrexate for two consecutive days without folic acid supplementation. Three days later, she developed oral ulcers, blisters, decreased oral intake, and fatigue. Lab results revealed pancytopenia, with markedly low white blood cells, hemoglobin, platelets, and absolute neutrophil count. Initially, Stevens-Johnson Syndrome (SJS) was considered due to mucosal symptoms, but lack of rash made methotrexate toxicity more likely. Rheumatology and hematology consultations led to the discontinuation of methotrexate, administration of filgrastim and leucovorin, and subsequent clinical improvement. This case highlights the diagnostic challenge in differentiating methotrexate toxicity from SJS, as both can present with mucosal lesions, though pancytopenia pointed toward toxicity. Despite methotrexate's known dose-dependent toxicity, this patient's reaction at a low dose suggests a rare idiosyncratic response, underscoring the importance of vigilance even with standard dosing and the necessity of folic acid supplementation to reduce adverse effects.
Journal Article
QTL analysis of fruit quality traits in two peach intraspecific populations and importance of maturity date pleiotropic effect
by
Eduardo, Iban
,
Rossini, Laura
,
Pozzi, Carlo
in
Acidity
,
Assisted selection
,
Biomedical and Life Sciences
2011
Two intraspecific peach breeding populations have been used to conduct a quantitative trait locus (QTL) analysis of fruit quality traits: an F₁ from the cross Bolero (B) x OroA (O) and an F₂ from the cross Contender (C) x Ambra (A). A total of 344 Prunus simple sequence repeats (SSRs) were analyzed in B, O, C, A parents and CxA F₁ hybrid. Eight SSR were mapped for the first time in peach. A multiplex-ready polymerase chain reaction (PCR) protocol has allowed considerable time and cost saving during genotyping steps. Two maps (B map and O map) were produced for BxO population following the pseudo-test cross strategy and one for CxA. No marker could be mapped on G6 for the B map, on G4 and G8 for the O map and on G5 for the CxA map. Both populations were phenotyped over 2 years for maturity date (MD), fruit weight, external fruit skin overcolor, juice total soluble solids (SSC, Brix degree), juice titrable acidity and juice pH. Data for blooming time and flower type were scored only for BxO in 2007. All traits had a normal distribution, except for MD which was bimodal in BxO and trimodal in CxA, where it was scored as a co-dominant trait. Up to two QTLs per trait were detected in each population, and most of them were located in the same region forming clusters of QTLs, especially on G4. This is likely due to a major pleiotropic effect of MD masking the identification of other QTLs for different traits.
Journal Article
Genome-enabled predictions for fruit weight and quality from repeated records in European peach progenies
2017
Background
Highly polygenic traits such as fruit weight, sugar content and acidity strongly influence the agroeconomic value of peach varieties. Genomic Selection (GS) can accelerate peach yield and quality gain if predictions show higher levels of accuracy compared to phenotypic selection. The available IPSC 9K SNP array V1 allows standardized and highly reliable genotyping, preparing the ground for GS in peach.
Results
A repeatability model (multiple records per individual plant) for genome-enabled predictions in eleven European peach populations is presented. The analysis included 1147 individuals derived from both commercial and non-commercial peach or peach-related accessions. Considered traits were average fruit weight (FW), sugar content (SC) and titratable acidity (TA). Plants were genotyped with the
9K IPSC
array, grown in three countries (France, Italy, Spain) and phenotyped for 3–5 years. An analysis of imputation accuracy of missing genotypic data was conducted using the software Beagle, showing that two of the eleven populations were highly sensitive to increasing levels of missing data. The regression model produced, for each trait and each population, estimates of heritability (FW:0.35, SC:0.48, TA:0.53, on average) and repeatability (FW:0.56, SC:0.63, TA:0.62, on average). Predictive ability was estimated in a five-fold cross validation scheme within population as the correlation of true and predicted phenotypes. Results differed by populations and traits, but predictive abilities were in general high (FW:0.60, SC:0.72, TA:0.65, on average).
Conclusions
This study assessed the feasibility of Genomic Selection in peach for highly polygenic traits linked to yield and fruit quality. The accuracy of imputing missing genotypes was as high as 96%, and the genomic predictive ability was on average 0.65, but could be as high as 0.84 for fruit weight or 0.83 for titratable acidity. The estimated repeatability may prove very useful in the management of the typical long cycles involved in peach productions. All together, these results are very promising for the application of genomic selection to peach breeding programmes.
Journal Article