Integration of QTL and transcriptome approaches for the identification of genes involved in tomato response to nitrogen deficiency.

Optimising plant nitrogen (N) usage and inhibiting N leaching loss in the soil-crop system is crucial to maintaining crop yield and reducing environmental pollution. This study aimed at identifying quantitative trait loci (QTLs) and differentially expressed genes (DEGs) between two N treatments in order to list candidate genes related to nitrogen-related contrasting traits in tomato varieties. We characterised a genetic diversity core-collection (CC) and a multi-parental advanced generation intercross (MAGIC) tomato population grown in greenhouse under two nitrogen levels and assessed several N-related traits and mapped QTLs. Transcriptome response under the two N conditions was also investigated through RNA sequencing of fruit and leaves in four parents of the MAGIC population. Significant differences in response to N input reduction were observed at the phenotypic level for biomass and N-related traits. Twenty-seven (27) QTLs were detected for three target traits (Leaf N content, leaf Nitrogen Balance Index and petiole NO3- content), ten and six at low and high N condition, respectively; while 19 QTLs were identified for plasticity traits. At the transcriptome level, 4,752 and 2,405 DEGs were detected between the two N conditions in leaves and fruits, respectively, among which 3,628 (50.6%) in leaves and 1,717 (71.4%) in fruit were genotype specific. When considering all the genotypes, 1,677 DEGs were shared between organs or tissues. Finally, we integrated DEGs and QTLs analyses to identify the most promising candidate genes. The results highlighted a complex genetic architecture of N homeostasis in tomato and novel putative genes useful for breeding tomato varieties requiring less N input.

In vivo selection of KPC-94 and KPC-95 in Klebsiella pneumoniae isolates from patients treated with ceftazidime/avibactam.

Ceftazidime/avibactam (CZA) is used to treat infections caused by Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp). Resistance to CZA is commonly related to point mutations in the blaKPC gene. Here we describe the in vivo emergence of CZA resistance in clinical isolates of KPC-Kp from four patients treated with this combination therapy. Four pre-therapy and five post-therapy KPC-Kp isolates were examined. Antibiogram (microdilution and gradient strips) and whole-genome sequencing were performed. The role of KPC mutations was validated by cloning blaKPC genes into competent Escherichia coli. All KPC-Kp isolates recovered before treatment with CZA were susceptible to CZA and produced KPC-3. Five KPC-Kp isolates recovered after treatment were resistant to this combination. Three post-therapy isolates from two patients produced KPC-31 (D179Y mutation). Additionally, we identified the novel substitution LN169-170H (KPC-94) in one isolate, and the combination of two independently described mutations, D179Y and A172T (KPC-95), in another isolate. All KPC-Kp isolates belonged to sequence type 512 (ST512). All CZA-resistant isolates with blaKPC variants had restoration of carbapenem susceptibility. In conclusion, resistance to CZA was related to blaKPC mutations, including the new KPC-94 and KPC-95 alleles, which do not cause carbapenem resistance.

Seismic Stereometry Reveals Preparatory Behavior and Source Kinematics of Intermediate-Size Earthquakes.

Although moderate-size earthquakes are poorly studied by lack of near-fault observations, they can provide key information about larger damaging earthquakes. Here we propose a new approach, inspired by double-difference relocation, that uses high-coherency waveforms recorded at neighboring sensors, to study the preparation phase and dynamics of moderate-size earthquakes. We validate this technique by analyzing the 2016, M w 5.2 Borrego Springs earthquake in Southern California and find consistent rupture velocities of 2 km/s highlighting two main rupture asperities. The analysis of the 2019, Ml5.2 Le Teil earthquake in France reveals slow nucleation at depth that migrates to the surface and propagates northward with a velocity of ∼2.8 km/s, highlighting two main rupture events also imaged by InSAR. By providing unprecedented resolution in our observation of the rupture dynamics, this approach will be useful in better understanding the preparation phase and rupture of both tectonic and induced earthquakes.

New Anyplex™ II MTB/MDR/XDR kit for detection of resistance mutations in M. tuberculosis cultures.

SETTINGS: The new Anyplex™ II MTB/MDR/XDR PCR assay enables the joint analysis of mutations conferring resistance to first- and second-line anti-tuberculosis drugs and the detection of Mycobacterium tuberculosis. OBJECTIVES: To evaluate the performance of the new Anyplex assay in detecting mutations that confer resistance to first- and second-line drugs in M. tuberculosis cultures. DESIGN: Results obtained using the new technique were compared with those obtained by phenotypic drug susceptibility testing (DST) and with two GenoType tests for the detection of mutations: GenoType(®) MTBDRplus and GenoType(®) MTBDRsl. RESULTS: For rifampicin resistance mutations, Anyplex displayed 97% sensitivity and 100% specificity compared with 100% and 100% for MTBDRplus. For isoniazid (INH) resistance, Anyplex displayed 61% sensitivity and 98% specificity compared with 62% and 98% for MTBDRplus. For second-line drugs, Anyplex recorded 95% sensitivity and 99% specificity in the detection of resistance to quinolones compared with 100% and 98% for the MTBDRsl. While both techniques displayed 100% specificity for aminoglycoside resistance mutations, sensitivity was 100% for Anyplex and 88% for MTBDRsl. CONCLUSIONS: Results obtained using Anyplex agreed strongly with those obtained using the two GenoType molecular techniques and with phenotypic DST, except in the case of INH, due to the large number of genes involved in resistance to this drug.

The neuroergonomic evaluation of human machine interface design in air traffic control using behavioral and EGG/ERP measures.

The Air Traffic Control (ATC) environment is complex and safety-critical. Whilst exchanging information with pilots, controllers must also be alert to visual notifications displayed on the radar screen (e.g., warning which indicates a loss of minimum separation between aircraft). Under the assumption that attentional resources are shared between vision and hearing, the visual interface design may also impact the ability to process these auditory stimuli. Using a simulated ATC task, we compared the behavioral and neural responses to two different visual notification designs--the operational alarm that involves blinking colored "ALRT" displayed around the label of the notified plane ("Color-Blink"), and the more salient alarm involving the same blinking text plus four moving yellow chevrons ("Box-Animation"). Participants performed a concurrent auditory task with the requirement to react to rare pitch tones. P300 from the occurrence of the tones was taken as an indicator of remaining attentional resources. Participants who were presented with the more salient visual design showed better accuracy than the group with the suboptimal operational design. On a physiological level, auditory P300 amplitude in the former group was greater than that observed in the latter group. One potential explanation is that the enhanced visual design freed up attentional resources which, in turn, improved the cerebral processing of the auditory stimuli. These results suggest that P300 amplitude can be used as a valid estimation of the efficiency of interface designs, and of cognitive load more generally.

[Investigation of antimicrobial resistance to Enterococcus faecium]. / Investigación de las resistencias a antimicrobianos en Enterococcus faecium.

We performed a antibiotic resistance study on Enterococcus faecium isolated from intrahospitalary and extrahospitalary samples between 2004 and 2010. Three different samples were studied; urine, blood and wound swabs, considering a strain per patient. We included in the study a global amount of 637 E. faecium isolares. We employed semiautomatic system WIDER I for identification and sensitivity testing. We considered susceptibility and resistance criteria recommended by MENSURA group. We found a susceptibility rate of 48.05% to betalactams, 100% to linezolid, and 99.46% to vancomycin. The resistance to aminoglycosides ranged between 41.41 and 73.55%. We obtained 6 isolates resistant to vancomycin one of them from an extrahospitalary strain and five from intrahospitalary strains. It seems that vancomycin resistance should be controlled.

[Evaluation of the variability in the susceptibility of Acinetobacter baumannii to tigecycline in the same medium with two methods of quantitative diffusion different commercial]. / Evaluación de la variabilidad en la sensibilidad de Acinetobacter baumannii a tigeciclina en un mismo medio de cultivo con dos métodos de difusión cuantitativos comerciales diferentes.

INTRODUCTION: Tigecycline may be a therapeutic alternative for the control of multidrug-resistant Acinetobacter baumannii, although there is no consensus on the cutoffs or susceptibility to the variability of the minimum inhibitory concentration (MIC) according to the culture medium and strips for the antibiogram against this microorganism by quantitative diffusion method. Therefore, the objective was to verify this variability and propose epsilometer test strip that more closely resemble to the standard method. MATERIAL AND METHODS: 38 strains of A. baumannii were selected and evaluated their susceptibility to tigecycline with two different commercial strips (E-TEST and Liofilchem). MICs were compared with those obtained by the standard technique of microdilution broth. RESULTS: MICs obtained by the Liofilchem strip were more similar to standard method than those obtained by E-TEST strips. CONCLUSION: In the two studied strips, higher MICs to those obtained by the standard method were observed leading to false-positive tigecicline resistance in many cases. However, the Liofilchem strip showed the results more closely resemble to the standard method.

Morphologic examination of the temporal bone by cone beam computed tomography: comparison with multislice helical computed tomography.

INTRODUCTION: High-resolution CT imaging is essential to diagnosis and follow-up of temporal bone pathology. Morphologically, CT is the reference examination. The requirement of long-term follow-up thus exposes patients to cumulative radiation doses. Limiting exposure to ionizing radiation is an increasing concern of public health authorities. The principal advantage of Cone Beam CT (CBCT) lies in a significant reduction in radiation dose. The main objective of the present study was to assess the morphologic concordance between CBCT and Multislice Helical Computed Tomography (MSCT) on 20 anatomic landmarks corresponding to regions of interest in clinical practice. The secondary objectives were to compare the two techniques qualitatively in stapes and footplate assessment and measurement of footplate thickness, and quantitatively in terms of dosimetry. MATERIAL AND METHODS: An experimental anatomical study was performed on 12 temporal bones from fresh human cadavers of unknown clinical history. Each underwent CBCT and MSCT. RESULTS: There was no significant difference in morphologic assessment of the temporal bones on the two techniques. Exploration of the stapes, incudostapedial joint, anterior stapediovestibular joint and footplate was qualitatively more precise on CBCT, and footplate thickness showed less overestimation than on MSCT. CBCT delivered 22 times less radiation than MSCT under the present experimental conditions. CONCLUSION: CBCT provides reliable morphologic assessment of temporal bone, thanks to higher spatial resolution than on MSCT, with significantly reduced radiation dose.

Protective proteins are differentially expressed in tomato genotypes differing for their tolerance to low-temperature storage.

When stored at low temperature, tomato fruits exhibit chilling injury symptoms, such as rubbery texture and irregular ripening. To identify proteins related to chilling tolerance, we compared two tomato near isogenic lines differing for their texture phenotype at harvest in a fruit-storage trial including two temperatures (4 and 20 degrees C) along several days of conservation. Fruit evolution was followed by assessing fruit color, ethylene emission and texture parameters. The most contrasted samples were submitted to proteomic analysis including two-dimensional electrophoresis and mass spectrometry of protein spots to identify the proteins, whose expression varied according to the genotype or the storage conditions. Unexpectedly, the most firm genotype at harvest was the most sensitive to cold storage. The other genotype exhibited a delay in fruit firmness loss leading to the texture differences observed after 20 days of 4 degrees C storage. The proteome analysis of these contrasted fruits identified 85 proteins whose quantities varied with temperature or genotype. As expected, cold storage decreased the expression of proteins related to maturation process, such as acidic invertase, possibly controlled post-translational regulation of polygalacturonase and up-regulated proteins related to freezing tolerance. However, the study point out proteins involved in the differential resistance to chilling conditions of the two lines. This includes specific isoforms among the large family of small heat shocked proteins, and a set of proteins involved in the defense against of the reticulum endoplasmic stress.

Investigación de las resistenciasa antimicrobianos en Enterococcusfaecalis / Investigation of Enterococcus faecalis antimicrobial resistance

Se llevó a cabo un estudio de resistencias a antimicrobianosde los aislamientos de Enterococcus faecalis intrahospitalariosy extrahospitalarios desde enero de 2004 hastaenero de 2008, procedentes de tres tipos de muestras: orinas,exudados y sangre, considerando una sola cepa por paciente.Se incluyeron en el estudio un total de 3.461 aislamientos deEnterococcus faecalis procedentes de muestras clínicas recibidasen el Servicio de Microbiología del Hospital UniversitarioReina Sofía de Córdoba (España). La metodología utilizadafue el método semiautomatizado WIDER I (Soria Melguizo),para la identificación y para el estudio de sensibilidades a antimicrobianos.Se consideraron los criterios de sensibilidad yresistencia recomendados por el grupo MENSURA.Se encontraron unos porcentajes de sensibilidad a betalactámicosdel 98,04%. En aminoglucósidos se obtuvieronlos mayores porcentajes de resistencia entre el 33,82% y48,01%. La sensibilidad a linezolid y a la vancomicina fue del100%.No parece que la incidencia de Enterococcus faecalis resistentea la vancomicina se considere un hecho preocupantehoy en día, pero sí que habría que vigilarlo (AU)

We performed an antibiotic resistance study on Enterococcusfaecalis isolated from intrahospitalary and extrahospitalarysamples between january 2004 and january2008. Three different samples were studied; urine, bloodand wound swabs, considering a strain per patient. We includedin the study a global amount of 3,641 Enterococcus faecalis isolations from clinical samples received at HospitalUniversitario Reina Sofía microbiology service inCórdoba (Spain). We employed semiautomatic systemWIDER I (Soria Melguizo) for identification and sensibilitytesting. We considered sensibility and resistance criteriarecommended by MENSURA group.We found a sensitivity rate of 98.04% to betalactamics.The highest resistance rates were obtained withaminoglycosides, between 33.82% and 48.01%. Linezolidand Vancomycin sensitivity was 100%. It seems thatvancomycin resistance is not a worrying issue today, butit should be controlled (AU)

Evaluation of new GenoType MTBDRplus for detection of resistance in cultures and direct specimens of Mycobacterium tuberculosis.

SETTINGS: Molecular methods frequently used in laboratories can now give us useful information about low growth bacteria. OBJECTIVE: To evaluate the new GenoType MTBDRplus assay for its ability to detect mutations in the 81-bp hotspot region of the rpoB gene, mutations in codon 315 of the katG gene and alterations in the inhA promoter region. DESIGN: Prospective resistance to rifampicin (RMP) and isoniazid (INH) study using Mycobacterium tuberculosis positive specimens and cultures comparing the results of GenoType MTBDRplus with those obtained phenotypically with the Bactec MGIT (Mycobacterial Growth Indicator Tube) 960. RESULTS: In 59 specimens (18 smear microscopy samples and 41 solid and liquid medium cultures), mutations were detected in all of 36 M. tuberculosis strains phenotypically resistant to RMP (100%), and in 35 of 37 strains phenotypically resistant to INH (94.59%). The new assay prompted a 21.6% increase in the direct detection of INH resistance in the strains studied, due to the incorporation of inhA promoter region probes in the test. CONCLUSIONS: The GenoType MTBDRplus assay is a valid method for detecting the most common mutations in strains resistant to RMP and INH. However, further phenotypic testing is required, as the assay failed to detect 100% of INH and RMP resistance.

Tomato fruit ascorbic acid content is linked with monodehydroascorbate reductase activity and tolerance to chilling stress.

Quantitative trait loci (QTL) mapping is a step towards the identification of factors regulating traits such as fruit ascorbic acid content. A previously identified QTL controlling variations in tomato fruit ascorbic acid has been fine mapped and reveals that the QTL has a polygenic and epistatic architecture. A monodehydroascorbate reductase (MDHAR) allele is a candidate for a proportion of the increase in fruit ascorbic acid content. The MDHAR enzyme is active in different stages of fruit ripening, shows increased activity in the introgression lines containing the wild-type (Solanum pennellii) allele, and responds to chilling injury in tomato along with the reduced/oxidized ascorbate ratio. Low temperature storage of different tomato introgression lines with all or part of the QTL for ascorbic acid and with or without the wild MDHAR allele shows that enzyme activity explains 84% of the variation in the reduced ascorbic acid levels of tomato fruit following storage at 4 degrees C, compared with 38% at harvest under non-stress conditions. A role is indicated for MDHAR in the maintenance of ascorbate levels in fruit under stress conditions. Furthermore, an increased fruit MDHAR activity and a lower oxidation level of the fruit ascorbate pool are correlated with decreased loss of firmness because of chilling injury.

The distribution of copia-type retrotransposons and the evolutionary history of tomato and related wild species.

Retrotransposons are mobile genetic elements that amplify throughout the genome and may be important contributors of genetic diversity. Their distribution is influenced by element behaviour and host-driven controls. We analysed the distribution of three copia-type retrotransposons, ToRTL1, T135 and Tnt1 using sequence-specific amplification polymorphism in self-compatible (SC) and incompatible (SI) species of Solanum subsection Lycopersicon, and genetically mapped polymorphic insertions in S. lycopersicum (tomato). The majority of polymorphic insertions (61%) are located in centromeric regions of the tomato genome. A significant positive relationship was detected between insertion polymorphisms and mating system, independent of selection as most insertions were found to be neutral. As insertion patterns successfully inferred interspecific relationships of Solanum subsection Lycopersicon, our results suggest that the distribution of ToRTL1, T135 and Tnt1 may essentially be determined by selection removing strongly deleterious insertions, with genetic drift and mating system, but not recombination rate, playing important roles.

[Antimicrobial susceptibility of Enterococcus faecalis isolated from patients in Córdoba (Spain)]. / Sensibilidad a los antimicrobianos de Enterococcus faecalis aislados de pacientes en la provincia de Córdoba (España).

Enterococcus faecalis is a pathogenic microorganism. The aim of this investigation was to study the antibiotic susceptibility of the strains isolated in Cordoba in a 20-month period (January 2004 to August 2005). Susceptibility rates to betalactamics were 98% to ampicillin and 99% to amoxicillin/clavulanic acid; high-dose aminoglycosides (streptomycin 1000 microg and gentamycin 500 microg) obtained 56% and 76%, respectively. We found no strains resistant to glycopeptides (vancomycin and teicoplanin) or to linezolid.

Sensibilidad a los antimicrobianos de Enterococcus faecalis aislados de pacientes en la provincia de Córdoba (España) / Antimicrobial susceptibility of Enterococcus faecalis isolated from patients in Córdoba (Spain)

Enterococcus faecalis es un microorganismo patógeno para el hombre. El objetivo de este estudio fue conocer la sensibilidad a diferentesantibióticos de los aislamientos obtenidos en la provincia de Córdoba en un periodo de 20 meses, de enero de 2004 a agosto de 2005. Losporcentajes de sensibilidad para los betalatámicos fueron del 98% a ampicilina y del 99% a amoxicilina-ácido clavulánico. Los aminoglucósidosestreptomicina y gentamicina, probados a altas dosis (estreptomicina 1000 µg y gentamicina 500 µg), obtuvieron un porcentaje desensibilidad del 56% y el 76%, respectivamente. No se encontró ninguna cepa resistente a glucopéptidos (vancomicina y teicoplanina) ni alinezolid

Enterococcus faecalis is a pathogenic microorganism. The aim of this investigation was to study the antibiotic susceptibility of the strains isolatedin Córdoba in a 20-month period (January 2004 to August 2005). Susceptibility rates to betalactamics were 98% to ampicillin and 99%to amoxicillin/clavulanic acid; high-dose aminoglycosides (streptomycin 1000 µg and gentamycin 500 µg) obtained 56% and 76%, respectively.We found no strains resistant to glycopeptides (vancomycin and teicoplanin) or to linezolid

Stability over genetic backgrounds, generations and years of quantitative trait locus (QTLs) for organoleptic quality in tomato.

The efficiency of marker-assisted backcross for the introgression of a quantitative trait locus (QTL) from a donor line into a recipient line depends on the stability of QTL expression. QTLs for six quality traits in tomato (fruit weight, firmness, locule number, soluble solid content, sugar content and titratable acidity) were studied in order to investigate their individual effect and their stability over years, generations and genetic backgrounds. Five chromosome regions carrying fruit quality QTLs were transferred following a marker-assisted backcross scheme from a cherry tomato line into three modern lines with larger fruits. Three sets of genotypes corresponding to three generations were compared: (1) an RIL population, which contained 50% of each parental genome, (2) three BC3S1 populations which segregated simultaneously for the five regions of interest but were almost fully homozygous for the recipient genome on the eight chromosomes carrying no QTL and (3) three sets of QTL-NILs (BC3S3 lines) which differed from the recipient line only in one of the five regions. QTL detection was performed in each generation, in each genetic background and during 2 successive years for QTL-NILs. About half of the QTLs detected in QTL-NILs were detected in both years. Eight of the ten QTLs detected in RILs were recovered in the QTL-NILs with the genetic background used for the initial QTL mapping experiment, with the exception of two QTLs for fruit firmness. Several new QTLs were detected. In the two other genetic backgrounds, the number of QTLs in common with the RILs was lower, but several new QTLs were also detected in advanced generations.

Evolución de la resistencia a la meticilina de Staphylococcus aureus en la provincia de Córdoba (España) en los años 2002-2005 / Evolution of methicillin resistance in Staphylococcus aureus in Cordoba (Spain) in the years 2002–2005

En los últimos años, Staphylococcus aureus resistente a la meticilina (SARM) se ha convertido en un patógeno humano de gran importancia.Nuestro objetivo ha sido estudiar la evolución de la resistencia a la meticilina de S. aureus aislados en nuestro hospital en un periodo decuatro años y comparar nuestra situación con la del resto del país y la de Europa. El porcentaje varió de un 39,9% en 2002 a un 46,4% en2005. Los servicios con mayor porcentaje fueron la UCI y los servicios quirúrgicos. No hallamos cepas con resistencia a los glucopéptidos

In the last few years, methicillin-resistant Staphylococcus aureus (MRSA) has become a very important human pathogen. Our aim was to studythe evolution of methicillin resistance of Staphylococcus aureus strains isolated in our hospital over a four-year period and to compare oursituation with the rest of Spain and Europe. The rates varied from 39.9% in 2002 to 46.4% in 2005. Units with the highest rate were ICU andsurgical wards. We found no glycopeptide-resistant strains

[Evolution of methicillin resistance in Staphylococcus aureus in Cordoba (Spain) in the years 2002-2005]. / Evolución de la resistencia a la meticilina de Staphylococcus aureus en la provincia de Córdoba (España) en los años 2002-2005.

In the last few years, methicillin-resistant Staphylococcus aureus (MRSA) has become a very important human pathogen. Our aim was to study the evolution of methicillin resistance of Staphylococcus aureus strains isolated in our hospital over a four-year period and to compare our situation with the rest of Spain and Europe. The rates varied from 39.9% in 2002 to 46.4% in 2005. Units with the highest rate were ICU and surgical wards. We found no glycopeptide-resistant strains.

A genetic map of candidate genes and QTLs involved in tomato fruit size and composition.

In order to screen for putative candidate genes linked to tomato fruit weight and to sugar or acid content, genes and QTLs involved in fruit size and composition were mapped. Genes were selected among EST clones in the TIGR tomato EST database (http://www.tigr.org/tdb/tgi/lgi/) or corresponded to genes preferentially expressed in the early stages of fruit development. These clones were located on the tomato map using a population of introgression lines (ILs) having one segment of Lycopersicon pennellii (LA716) in a L. esculentum (M82) background. The 75 ILs allowed the genome to be segmented into 107 bins. Sixty-three genes involved in carbon metabolism revealed 79 loci. They represented enzymes involved in the Calvin cycle, glycolysis, the TCA cycle, sugar and starch metabolism, transport, and a few other functions. In addition, seven cell-cycle-specific genes mapped into nine loci. Fourteen genes, primarily expressed during the cell division stage, and 23 genes primarily expressed during the cell expansion stage, revealed 24 and 26 loci, respectively. The fruit weight, sugars, and organic acids content of each IL was measured and several QTLs controlling these traits were mapped. Comparison between map location of QTLs and candidate gene loci indicated a few candidate genes that may influence the variation of sugar or acid contents. Furthermore, the gene/QTL locations could be compared with the loci mapped in other tomato populations.

Marker-assisted introgression of five QTLs controlling fruit quality traits into three tomato lines revealed interactions between QTLs and genetic backgrounds.

The evaluation of organoleptic quality of tomato fruit requires physical, chemical and sensory analyses, which are expensive and difficult to assess. Therefore, their practical use in phenotypic selection is difficult. In a previous study, the genetic control of several traits related to organoleptic quality of fresh-market tomato fruit was investigated. Five chromosome regions strongly involved in organoleptic quality attributes were then chosen to be introgressed into three different recipient lines through marker-assisted selection. A marker-assisted backcross (MABC) strategy was performed, as all the favorable alleles for quality traits were provided by the same parental tomato line, whose fruit weight (FW) and firmness were much lower than those of the lines commonly used to develop fresh market varieties. Three improved lines were obtained after three backcrossing and two selfing generations. The implementation of the MABC scheme is described. The three improved lines were crossed together and with the recipient lines in a half-diallel mating scheme, and the simultaneous effect of the five quantitative trait locus (QTL) regions was compared in different genetic backgrounds. Significant effects of the introgressed regions and of the genetic backgrounds were shown. Additive effects were detected for soluble solid and reducing sugar content in two genetic backgrounds. A partially dominant effect on titratable acidity was detected in only one genetic background. In contrast, additive to dominant unfavorable effects of the donor alleles were detected for FW and locule number in the three genetic backgrounds. Recessive QTL effects on firmness were only detected in the two firmest genetic backgrounds. Comparison of the hybrids in the half-diallel gave complementary information on the effects of: (1) the alleles at the selected regions, (2) the genetic backgrounds and (3) their interaction. Breeding efficiency strongly varied according to the recipient parent, and significant interactions between QTLs and genetic backgrounds were shown for all of the traits studied.