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1.
AIDS Care ; 35(6): 876-882, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-35277091

RESUMO

Previous studies showed that Erotic industry sShows (ES) were appropriate events for sexual health promotion and testing interventions. A cross-sectional survey exploring screening practices, sexual behaviors, substance use, and sexual motives for substance use was conducted in ES in December 2017 and completed by 781 respondents. Overall, . Eighteen18% percent reported substance use in the last 3 months (51% alcohol), 26%. Twenty-six percent reported a sexual purpose for substance use. Main sexual partners were spouse (68%), regular (21%), unknown (18%) and several (17%) partners. Main sexual practices were libertinism (22%), partner swapping (15%) and threesome (15%). Twenty-seven percent of respondents reported cContactless sex was reported by 27% of the respondents. 18% reported no previous HIV test. Univariate analysis showed that having or not previous HIV test was linked to male sex (76.8% vs. 54.5%, p < 10-3), alcohol consumption in the last three months (58.7% vs. 49.4%, p = .043), number of drugs in a lifetime (1.3% vs. 1.6%, p = .022), sexual partnership with spouse/long-term partner (57.3% vs. 70.5%; p = .002), at least one multiple-partner sexual practice (23.1% vs. 31.8%, p = .040) and type of sexual attraction (p = <10-3). Results contribute to establishing the usefulness of HIV-testing and awareness campaigns in ES eventsand informing potential combined risk behaviors and related interventions.


Assuntos
Infecções por HIV , Transtornos Relacionados ao Uso de Substâncias , Masculino , Humanos , Estudos Transversais , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Comportamento Sexual , Parceiros Sexuais , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Assunção de Riscos
2.
Encephale ; 48(2): 118-124, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33994159

RESUMO

The aim of this article was to study the impact of the COVID19 lockdown on anxiety and depressive symptoms on the basis of responses to an online survey from 1753 French-speaking subjects, conducted between April 27 and May 11, 2020. METHOD: Using a biopsychosocial model, the effects of socio-demographic characteristics (age, gender at birth, socio-professional category, sexual orientation), lockdown conditions (material factors: urban density of the place of residence, surface area of the place of residence during lockdown), social characteristics: living with a partner during lockdown, presence of children during lockdown) and psychosocial history (attachment styles) on anxiety - evaluated on the GAD7 - and depression - evaluated on the MDI - were investigated. Ordinal regression analyses were conducted. RESULTS: The rates of depression observed (moderate or severe depression: 22.5%) and anxiety (moderate or severe anxiety: 18.4%) were higher than usual but lower than what has been documented in other studies on the effects of lockdown. Women appeared to be more vulnerable than men (Anxiety: AOR=1.647, CI 95%=1.647-2.530; Depression: AOR=1.622, CI 95%=1.274-2.072). Bisexual individuals had an increased likelihood of anxiety symptoms (AOR=1.962, CI 95%=1.544-2.490) and depression (AOR=1.799, CI 95%=1.394-2.317). For homosexuals, only links with depression were observed (AOR=1.757, CI 95%=1.039-2.906). People in a situation of economic vulnerability were more prone to anxiety disorders (e.g. people with no working activity: AOR=1.791, CI 95%=1.147-2.790) or depression (e.g. people with no working activity: AOR=2.581, CI 95%=1.633-4.057). Links with attachment styles were also found. Fearful subjects were particularly vulnerable (anxiety: AOR=2.514, CI 95%=1.985-3.190; depression: AOR=2.521, CI 95%=1.938-3.289), followed by subjects with an anxious attachment style (anxiety: AOR=1.949, CI 95%=1.498-2.540; depression: AOR=1.623, CI 95%=1.207-2.181). The impact of lockdown on avoidant subjects only concerned depression (AOR=1.417, CI 95%=1.034-1.937). Being with a partner during lockdown appeared to have a protective effect against depression (AOR=.693, CI 95%=.555-.866). Neither the presence of children, the surface area of the lockdown residence, nor the population density of the place of residence was associated with anxiety or depression. CONCLUSION: The impact of lockdown on mental health depends on a range of dimensions that need to be apprehended in order to tailor post-lockdown psychological and social support. Management based on a biopsychosocial approach should be favored.


Assuntos
COVID-19 , Ansiedade/epidemiologia , Ansiedade/psicologia , Transtornos de Ansiedade/epidemiologia , Criança , Controle de Doenças Transmissíveis , Depressão/epidemiologia , Depressão/psicologia , Feminino , Humanos , Recém-Nascido , Masculino , SARS-CoV-2
3.
Phytochemistry ; 135: 24-33, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27964835

RESUMO

Water deficiency has become a major issue for modern agriculture as its effects on crop yields and tuber quality have become more pronounced. Potato genotypes more tolerant to water shortages have been identified through assessment of yield and dry matter. In the present study, a combination of metabolite profiling and physiological/agronomical measurements has been used to explore complex system level responses to non-lethal water restriction. The metabolites identified were associated with physiological responses in three different plant tissues (leaf, root and tuber) of five different potato genotypes varying in susceptibility/tolerance to drought. This approach explored the potential of metabolite profiling as a tool to unravel sectors of metabolism that react to stress conditions and could mirror the changes in the plant physiology. The metabolite results showed different responses of the three plant tissues to the water deficit, resulting either in different levels of the metabolites detected or different metabolites expressed. The leaf material displayed the most changes to drought as reported in literature. The results highlighted genotype-specific signatures to water restriction over all three plant tissues suggesting that the genetics can predominate over the environmental conditions. This will have important implications for future breeding approaches.


Assuntos
Solanum tuberosum/química , Estresse Fisiológico , Água/metabolismo , Desidratação , Secas , Regulação da Expressão Gênica de Plantas , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Tubérculos/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Solanum tuberosum/genética
4.
Prog Urol ; 23(9): 562-74, 2013 Jul.
Artigo em Francês | MEDLINE | ID: mdl-23830250

RESUMO

OBJECTIVE: To evaluate the clinical presentation of women's sexual desire disorders (SDD) and therapeutic options, suggested in the literature. MATERIAL AND METHODS: Review of articles published on this subject in the Medline database, selected according to their scientific relevance, of consensus conferences and published guidelines. RESULTS: Female sexual desire is eminently multifactorial. The clinician should take into account the distress of the woman presenting with a SDD by relating this to the sexual history and the general context (pathological, biological…) together with the relationship with the partner. Other sexual disorders should be considered particularly arousal disorders which are frequently associated with SDD in women. SDD is one of the most difficult symptoms of female sexual dysfunction to treat since it is difficult to delimit the normal and the pathological. Without desire, the lack of sexual activity cannot be perceived as suffering. However, the consequences of this situation mean that she will consult the specialist fearing either that she could lose her partner, or that she is different in a normative society. CONCLUSION: A woman who is fulfilled will not have a problem with desire. The therapeutic objective can be to re-establish reactive desire in the affective context of the couple. The complexity and the multifactorial nature of TDS in women means that no unique solution is satisfactory; the initial assessment and a precise aim for therapeutic management are essential.


Assuntos
Disfunções Sexuais Psicogênicas , Feminino , Humanos , Libido , Disfunções Sexuais Psicogênicas/diagnóstico , Disfunções Sexuais Psicogênicas/etiologia , Disfunções Sexuais Psicogênicas/fisiopatologia , Disfunções Sexuais Psicogênicas/terapia , Sexualidade
5.
Theor Appl Genet ; 120(6): 1265-78, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20063145

RESUMO

Main and interaction effects of day-length and pathogen isolate on the reaction and expression of field resistance to Phytophthora infestans were analyzed in a sample of standard clones for partial resistance to potato late blight, and in the BCT mapping population derived from a backcross of Solanum berthaultii to Solanum tuberosum. Detached leaves from plants grown in field plots exposed to short- and long day-length conditions were independently inoculated with two P. infestans isolates and incubated in chambers under short- and long photoperiods, respectively. Lesion growth rate (LGR) was used for resistance assessment. Analysis of variance revealed a significant contribution of genotype x isolate x day-length interaction to variation in LGR indicating that field resistance of genotypes to foliar late blight under a given day-length depended on the infecting isolate. An allele segregating from S. berthaultii with opposite effects on foliar resistance to late blight under long- and short day-lengths, respectively, was identified at a quantitative trait locus (QTL) that mapped on chromosome 1. This allele was associated with positive (decreased resistance) and negative (increased resistance) additive effects on LGR, under short- and long day-length conditions, respectively. Disease progress on whole plants inoculated with the same isolate under field conditions validated the direction of its effect in short day-length regimes. The present study suggests the occurrence of an isolate-specific QTL that displays interaction with isolate behavior under contrasting environments, such as those with different day-lengths. This study highlights the importance of exposing genotypes to a highly variable population of the pathogen under contrasting environments when stability to late blight resistance is to be assessed or marker-assisted selection is attempted for the manipulation of quantitative resistance to late blight.


Assuntos
Imunidade Inata/imunologia , Fotoperíodo , Phytophthora infestans/isolamento & purificação , Doenças das Plantas/imunologia , Doenças das Plantas/parasitologia , Solanum tuberosum/imunologia , Solanum tuberosum/parasitologia , Agricultura , Bioensaio , Genótipo , Escore Lod , Doenças das Plantas/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/parasitologia , Locos de Características Quantitativas/genética , Solanum tuberosum/genética , Solanum tuberosum/crescimento & desenvolvimento
6.
Theor Appl Genet ; 114(6): 1051-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17394033

RESUMO

Major gene inheritance of resistance to Potato leafroll virus (PLRV) was demonstrated in a parthenogenic population derived from the highly resistant tetraploid andigena landrace, LOP-868. This major gene or chromosome region seems to control a single mechanism for resistance to infection and virus accumulation in this source. About 149 dihaploid lines segregated in a ratio of 107 resistant to 32 susceptible, fitting the expected ratio for inheritance of a duplex gene under random chromatid segregation. A tetraploid AFLP map was constructed using as reference the ultra high density (UHD) map. All AFLP markers associated with PLRV resistance mapped to the same linkage group. Map position was confirmed by analysis of previously-mapped SSR markers. Rl (adg) is located on the upper arm of chromosome V, at 1 cM from its most closely linked AFLP marker, E35M48.192. This marker will be used to develop allele-specific primers or a pair of flanking PCR-based markers for their use in marker assisted selection.


Assuntos
Mapeamento Cromossômico , Genes de Plantas , Imunidade Inata/genética , Luteovirus/patogenicidade , Solanum tuberosum/genética , Solanum tuberosum/virologia , Cromossomos de Plantas , DNA de Plantas/genética , DNA de Plantas/isolamento & purificação , Ligação Genética , Marcadores Genéticos , Técnicas de Amplificação de Ácido Nucleico , Partenogênese , Doenças das Plantas/genética , Doenças das Plantas/virologia , Polimorfismo Genético , Solanum tuberosum/classificação , Solanum tuberosum/imunologia
7.
Encephale ; 32(5 Pt 1): 697-704, 2006 Oct.
Artigo em Francês | MEDLINE | ID: mdl-17099593

RESUMO

In spite of the frequency of sexual dysfunction in schizophrenic patients and antipsychotic-treated schizophrenic patients, few studies have been performed. The relationship of schizophrenia to sexual pathology is variable and complex, and of course different between men and women. Few evaluation methods have been proposed or validated. Antipsychotics may improve some aspects of sexual behaviour in schizophrenic patients. However, sexual dysfunction is also a possible side effect of these drugs. The evaluation of antipsychotics is often restricted to prolactin measurement, the relationship with sexual disorders of which has not been fully established. Preliminary data suggest that the capacity to induce sexual disorders differs from one antipsychotic to another. The available data on the mechanisms of sexual dysfunction, the pharmacological profile and the sexual effects of classical neuroleptics (haloperidol and thioridazine) and second generation antipsychotics available in France (amisulpride, clozapine, risperidone, olanzapine) are reviewed.


Assuntos
Antipsicóticos/efeitos adversos , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Comportamento Sexual/efeitos dos fármacos , Disfunções Sexuais Fisiológicas/induzido quimicamente , Antipsicóticos/uso terapêutico , Estudos Transversais , Disfunção Erétil/induzido quimicamente , Disfunção Erétil/epidemiologia , Feminino , França , Humanos , Masculino , Esquizofrenia/epidemiologia , Disfunções Sexuais Fisiológicas/diagnóstico , Disfunções Sexuais Fisiológicas/epidemiologia , Disfunções Sexuais Fisiológicas/psicologia
8.
Theor Appl Genet ; 112(4): 674-87, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16402191

RESUMO

Phytophthora infestans, the causal agent of late blight, threatens potato production worldwide. An important tool in the management of the disease is the use of resistant varieties. Eleven major resistance genes have been identified and introgressed from Solanum demissum. However, new sources of resistance are continually sought. Here, we report the characterization and refined genetic localization of a resistance gene previously identified as Rber in a backcross progeny of Solanum tuberosum and Solanum berthaultii. In order to further characterize Rber, we developed a set of P. infestans isolates capable of identifying each of the 11 R-genes known to confer resistance to late blight in potato. Our results indicate that Rber is a new resistance gene, different from those recognized in S. demissum, and therefore, it has been named RPi-ber according to the current system of nomenclature. In order to add new molecular markers around RPi-ber, we used a PCR-based mapping technique, named MASP-map, which located RPi-ber in a 3.9 cM interval between markers CT240 and TG63 on potato chromosome X. The location of RPi-ber coincides with an area involved in resistance to different pathogens of potato and tomato.


Assuntos
Mapeamento Cromossômico , Genes de Plantas , Marcadores Genéticos , Imunidade Inata , Phytophthora/patogenicidade , Solanum tuberosum , Solanum , Cromossomos de Plantas , DNA de Plantas/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Polimorfismo de Fragmento de Restrição , Solanum/genética , Solanum/microbiologia , Solanum tuberosum/genética , Solanum tuberosum/microbiologia
9.
Theor Appl Genet ; 111(6): 1201-14, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16133311

RESUMO

The cultivated potato, Solanum tuberosum, is affected by a variety of diseases with late blight, caused by Phytophthora infestans, being the most severe. Wild potato species have proven to be a continuing source of resistance, sometimes of an extreme type, to this disease. The present study constructs the first late blight linkage map of a member of series Piurana, S. paucissectum, a tuber-bearing relative of potato, using probes for conserved sequences from potato and tomato. Eight probes mapped to unexpected linkage groups, but syntenic differences with prior maps of potato were not supported by any blocks of rearranged chromosome segments. All 12 linkage groups were resolved and significant associations with late blight resistance were found on chromosomes 10, 11 and 12. A major quantitative trait locus (QTL) on chromosome 11 accounts for more than 25% of the phenotypic variance measured in a field trial. Crossing of S. paucissectum with cultivated potato resulted in very few seeds indicating partial reproductive barriers. Differential reactions of accessions of this potential donor species with simple and complex isolates of P. infestans suggest that it carries major resistance genes that are not those previously described from the Mexican species, S. demissum. However, the additivity of the QTL effects argues for the quantitative nature of resistance in this cross.


Assuntos
Mapeamento Cromossômico , Cromossomos de Plantas/genética , Hibridização Genética , Imunidade Inata/genética , Phytophthora , Doenças das Plantas/microbiologia , Solanum/genética , Análise de Variância , Southern Blotting , Cruzamentos Genéticos , Peru , Doenças das Plantas/genética , Locos de Características Quantitativas , Reprodução/genética
10.
Theor Appl Genet ; 111(3): 456-66, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15942755

RESUMO

Microsatellites, or simple sequence repeats (SSRs) are very useful molecular markers for a number of plant species. They are commonly used in cultivar identification, plant variety protection, as anchor markers in genetic mapping, and in marker-assisted breeding. Early development of SSRs was hampered by the high cost of library screening and clone sequencing. Currently, large public SSR datasets exist for many crop species, but the number of publicly available, mapped SSRs for potato is relatively low (approximately 100). We have utilized a database mining approach to identify SSR-containing sequences in The Institute For Genomic Research Potato Gene Index database (http://www.tigr.org), focusing on sequences with size polymorphisms present in this dataset. Ninety-four primer pairs flanking SSR sequences were synthesized and used to amplify potato DNA. This study rendered 61 useful SSRs that were located in pre-existing genetic maps, fingerprinted in a set of 30 cultivars from South America, North America, and Europe or a combination thereof. The high proportion of success (65%) of expressed sequence tag-derived SSRs obtained in this work validates the use of transcribed sequences as a source of markers. These markers will be useful for genetic mapping, taxonomic studies, marker-assisted selection, and cultivar identification.


Assuntos
DNA de Plantas/genética , Etiquetas de Sequências Expressas , Genes de Plantas , Repetições de Microssatélites , Solanum tuberosum/genética , Mapeamento Cromossômico , Bases de Dados Factuais , Ligação Genética , Marcadores Genéticos , Genoma de Planta
12.
Theor Appl Genet ; 108(5): 881-90, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14647900

RESUMO

Characterization of nearly 1,000 cultivated potato accessions with simple sequence repeats (SSRs; also referred to as microsatellites) has allowed the identification of a reference set of SSR markers for accurate and efficient genotyping. In addition, 31 SSRs are reported here for a potato genetic map, including new map locations for 24 of them. A first criterion for this proposed reference set was ubiquity of the SSRs in the eight landrace cultivar groups of the potato, Solanum tuberosum. All SSRs tested in the present study displayed the same allele phenotypes and allele size range in the diverse germplasm set as in the advanced potato cultivar germplasm in which they were originally discovered. Thirteen of 13 SSR products from all cultivar groups are shown to cross-hybridize with the corresponding SSR product of the source cultivar to ascertain sequence homology. Other important SSR selection criteria are quality of amplification products, locus complexity, polymorphic index content, and well-dispersed location on a potato genetic map. Screening of 156 SSRs allowed the identification of a highly informative and user-friendly set comprising 18 SSR markers for use in characterization of potato genetic resources. In addition, we have identified true- and pseudo-multiplexing SSRs for even greater efficiency.


Assuntos
Genótipo , Repetições de Microssatélites/genética , Solanum tuberosum/genética , Alelos , Marcadores Genéticos , Polimorfismo Genético , Sequências Repetitivas de Ácido Nucleico
13.
Am J Bot ; 87(11): 1647-55, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11080115

RESUMO

Microsatellite amplification was performed on cassava (Manihot esculenta) and six other different species (all wild) of the Manihot genus. We used ten pairs of microsatellite primers previously developed from cassava, detecting 124 alleles in a sample of 121 accessions of the seven species. The number of alleles per locus ranged from four to 21 alleles, and allelic diversity was greater in the wild species than in cassava. Seventy-nine alleles, including unique ones, were detected in the wild species but were not found in the crop. The lower level of heterozygosity in some wild species probably resulted from a combination of fine-scale differentiation within the species and the presence of null alleles. Overall, microsatellite primers worked across the genus, but, with increasing genetic distance, success in amplifying loci tended to decrease. No accession of M. aesculifolia, M. carthaginensis, and M. brachyloba presented a banding pattern at locus Ga-140; neither did one appear for M. aesculifolia at locus Ga-13. Previous work with amplified fragment length polymorphism (AFLP) markers and this microsatellite analysis show that these three wild taxa are the most distant relatives of the crop, whereas the wild forms M. esculenta subsp. flabellifolia and M. esculenta subsp. peruviana appear to be the closest.

14.
Conserv Biol ; 14(6): 1755-1765, 2000 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-35701903

RESUMO

Genebank collection databases can be used for ecogeographical studies under the assumption that the accessions are a geographically unbiased sample. We evaluated the representativeness of a collection of wild potatoes from Bolivia and defined and assessed four types of bias: species, species-area, hotspot, and infrastructure. Species bias is the sampling of some species more often than others. Species-area bias is a sampling that is disproportionate to the total area in which a species is found. Hotspot bias is the disproportionate sampling of areas with high levels of diversity. Infrastructure bias is the disproportionate sampling of areas near roads and towns. Each of these biases is present in the Bolivian wild potato collection. The infrastructure bias was strong: 60% of all wild potato accessions were collected within 2 km of a road, as opposed to 22%, if collections had been made randomly. This analysis can serve as a guide for future collecting trips. It can also provide baseline information for the application of genebank data in studies based on geographic information systems.


RESUMEN: Las bases de datos de los bancos de germoplasma pueden ser usadas para estudios ecogeográficos bajo el supuesto que las entradas constituyen una muestra geográficamente imparcial. Evaluamos la representatividad geográfica de una colección de papas silvestres de Bolivia y definimos y evaluamos cuatro tipos de sesgos: sesgos de especie, de especie-área, de áreas con gran diversidad ( hotspot), y de infraestructura. El sesgo de especie implica el muestrear más algunas especies que otras. El sesgo de especie-área es un muestreo que es desproporcionado con respecto al total del área en la cual se encuentra una especie. El sesgo de "hotspot" es el muestreo desproporcionado de áreas con niveles altos de diversidad. El sesgo por infraestructura es aquel muestreo desproporcionado de áreas cercanas a carreteras y pueblos. Cada uno de estos sesgos se presenta en la colección de papas silvestres de Bolivia. El sesgo por infraestructura fue muy elevado: 60% de todas las entradas de papas silvestres fueron colectados dentro de un radio de 2 km de distancia de las carreteras, cuando se debería esperar un 22% si las colectas se hubieran hecho de manera aleatoria. Este análisis puede servir como guía para futuras exploraciones y proporciona una base para la aplicación de los datos de bancos de genes en estudios basados en sistemas de información geográfica.

15.
Genome ; 42(2): 163-72, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10231955

RESUMO

Cassava bacterial blight (CBB) is caused by Xanthomonas axonopodis pv. manihotis (Xam). Resistance is found in Manihot esculenta and, in addition, has been introgressed from a wild relative, M. glaziovii. The resistance is thought to be polygenic and additively inherited. Ninety-three varieties of M. esculenta (Crantz) were assessed by AFLPs for genetic diversity and for resistance to CBB. AFLP analysis was performed using two primer combinations and a 79.2% level of polymorphism was found. The phenogram obtained showed between 74% and 96% genetic similarity among all cassava accessions analysed. The analysis permitted the unique identification of each individual. Two Xam strains were used for resistance screening. Variation in the reaction of cassava varieties to Xam strains was observed for all plant accessions. The correlation of resistance to both strains, had a coefficient of 0.53, suggesting the independence of resistance to each strain. Multiple correspondence analysis showed a random distribution of the resistance/susceptibility response with respect to overall genetic diversity as measured by AFLP analysis. A total heterozygosity index was calculated to determine the diversity within clusters as well as among them. Our results demonstrate that resistance to CBB is broadly distributed in cassava germplasm and that AFLP analysis is an effective and efficient means of providing quantitative estimates of genetic similarities among cassava accessions.


Assuntos
Variação Genética , Manihot/genética , Doenças das Plantas/genética , Polimorfismo de Fragmento de Restrição , Manihot/classificação , Manihot/imunologia , Manihot/microbiologia
18.
Genome ; 39(5): 1039-43, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18469953

RESUMO

The informativeness and inheritance of randomly amplified polymorphic DNA (RAPD) markers were investigated in an intraspecific F1 progeny derived from two heterozygous parents. The analysis confirmed the utility of RAPD markers for comparing candidate parents for the development of a molecular genetic map, and provided numerous markers for linkage analysis in a crop with a very limited history of classical or molecular genetic studies. Six potential parental lines (themselves F1 hybrid clones) showed between 1.82 and 0.62 segregating bands per primer in three hybrid families. Forty-three percent (309) of 722 primers produced polymorphic products in the most informative of these three crosses, revealing 328 single-dose (SD) markers segregating 1:1 for presence/absence in a progeny of 90 individuals. A second class of informative markers were those present in both parents but segregating in the progeny. Fifty-seven or 67% of the monomorphic but segregating markers exhibited the 3:1 ratio expected for SD dominant markers in a cross between heterozygotes. Linkage groups were constructed from the segregation of SD RAPD markers originating in the female (TMS 30572) and the male (CM2177-2) parent. Key words : RAPDs, molecular markers, genetic segregation, Manihot, single-dose markers.

19.
Theor Appl Genet ; 93(3): 307-16, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24162285

RESUMO

Quantitative trait loci (QTLs) affecting tuberization were detected in reciprocal backcrosses between Solanum tuberosum and S. berthaultii. Linkage analyses were performed between traits and RFLP alleles segregating from both the hybrid and the recurrent parent using a set of framework markers from the potato map. Eleven distinct loci on seven chromosomes were associated with variation in tuberization. Most of the loci had small effects, but a QTL explaining 27% of the variance was found on chromosome 5. More QTLs were detected while following alleles segregating from the recurrent S. tuberosum parent used to make the backcross than were detected by following alleles segregating from the hybrid parent. More than half of the alleles favoring tuberization were at least partly dominant. Tuberization was favored by an allele from S. berthaultii at 3 of the 5 QTLs detected by segregation from the hybrid parent. The additive effects of the QTLs for tuberization explained up to 53% of the phenotypic variance, and inclusion of epistatic effects increased this figure to 60%. The most common form of epistasis was that in which presence of an allele at each of 2 loci favoring tuberization was no more effective than the presence of a favorable allele at 1 of the 2 loci. The QTLs detected for tuberization traits are discussed in relationship to those previously detected for trichome-mediated insect resistance derived from the unadapted wild species.

20.
Theor Appl Genet ; 93(3): 317-24, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24162286

RESUMO

The potential loss of chemical sprout inhibitors because of public concern over the use of pesticides underscores the desirability of breeding for long dormancy of potato (Solanum tuberosum L.) tubers. Quantitative trait locus (QTL) analyses were performed in reciprocal backcrosses between S. tuberosum and S. berthaultii toward defining the complexity of dormancy. S. berthaultii is a wild Bolivian species characterized by a short-day requirement for tuberization, long tuber dormancy, and resistance to several insect pests. RFLP alleles segregating from the recurrent parents as well as from the interspecific hybrid were monitored in two segregating progenies. We detected QTLs on nine chromosomes that affected tuber dormancy, either alone or through epistatic interactions. Alleles from the wild parent promoted dormancy, with the largest effect at a QTL on chromosome 2. Long dormancy appeared to be recessive in the backcross to S. berthaultii (BCB). In BCB the additive effects of dormancy QTLs accounted for 48% of the measured phenotypic variance, and adding epistatic effects to the model explained only 4% more. In contrast, additive effects explained only 16% of the variance in the backcross to S. tuberosum (BCT), and an additional 24% was explained by the inclusion of epistatic effects. In BCB variation at all QTLs detected was associated with RFLP alleles segregating from the hybrid parent; in BCT all QTLs except for two found through epistasis were detected through RFLP alleles segregating from the recurrent parent. At least three dormancy QTLs mapped to markers previously found to be associated with tuberization in these crosses.

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