RESUMO
The aim of this study was to detect polypeptides and genomic regions associated with fruit quality traits in a backcross generation using as parent the Argentinean cultivated tomato Caimanta of Solanum lycopersicum and the wild accession LA722 of S. pimpinellifolium. We tested two types of molecular marker: polypeptide profile (at two ripening stages, mature green and red ripe) and SRAP (sequence-related amplified polymorphism). A polypeptide of 45 kDa present in the wild parents at the mature green stage was associated with larger fruit and long shelf life. Some amplification fragments from SRAP markers were associated with more than one quality trait such as fruit color, firmness, titratable acidity, and fruit soluble solids content. This study demonstrated for the first time the usefulness of the polypeptide profiles of pericarp and SRAP markers in finding associations with quality fruit traits in a tomato backcross generation.
Assuntos
Frutas/genética , Hibridização Genética , Peptídeos/genética , Solanum lycopersicum/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Frutas/crescimento & desenvolvimento , Variação Genética , Solanum lycopersicum/crescimento & desenvolvimento , Peptídeos/isolamento & purificação , Fenótipo , Locos de Características Quantitativas/genéticaRESUMO
The objective of this work was to evaluate the in vivo acetohydroxyacid synthase (AHAS) activity response to imidazolinones and its possible use as a selection method for evaluating AHAS inhibitor resistance. In vivo AHAS assay and the comparison of parameters from dose-response curves have been used as a valid tool for comparing sunflower lines and hybrids differing in imidazolinone resistance. The sunflower resistant genotypes evaluated here were 100-fold and 20-fold more resistant compared with the susceptible line for imazethapyr and imazapyr, respectively. This assay also allowed discrimination of homozygous from heterozygous genotypes for I(mr1) locus that codify for the catalytic subunit of AHAS. The in vivo AHAS assay described in this study was useful for the selection of sunflower genotypes differing in herbicide resistance and could be a useful tool when breeding for imidazolinone resistance in sunflower.
Assuntos
Acetolactato Sintase/genética , Genes de Plantas , Genótipo , Helianthus/genética , Resistência a Herbicidas/genética , Herbicidas , Proteínas de Plantas/genética , Acetolactato Sintase/antagonistas & inibidores , Loci Gênicos , Helianthus/enzimologia , Heterozigoto , Homozigoto , Hibridização Genética , Imidazóis , Niacina/análogos & derivados , Ácidos Nicotínicos , Proteínas de Plantas/antagonistas & inibidores , Subunidades ProteicasRESUMO
Sunflower (Helianthus annuus L.) has been cultivated both as an oilseed and as an ornamental plant. Several protocols have been described for the micropropagation, direct plant regeneration by organogenesis being acceptable for this plant species. Besides a strong genotype dependency, the type and ontogenic stage of explants, environmental conditions of the culture, and media composition affect sunflower organogenesis. Several problems have hindered the ability to regenerate normal shoots; the most common being hyperhydricity and precocious flowering. This chapter describes a protocol for direct shoot regeneration from cotyledons developed and established in our laboratory, as well as the improvement regenerated shoot quality.
Assuntos
Técnicas de Cultura , Helianthus/crescimento & desenvolvimento , Regeneração , Aclimatação , Proliferação de Células , Cotilédone/crescimento & desenvolvimento , Meios de Cultura , Regulação da Expressão Gênica de Plantas , Genótipo , Germinação , Helianthus/embriologia , Helianthus/genética , Organogênese , Fenótipo , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Fatores de TempoRESUMO
The effects of wild germplasm on tomato fruit shelf life have not yet been completely evaluated. Three different genotypes of Lycopersicon esculentum (a cultivated variety, a homozygote for nor and a homozygote for rin), LA1385 of L. esculentum var. cerasiforme, LA722 of L. pimpinellifolium, and 10 diallel hybrids were assayed. Mean values of fruit shelf life, weight, shape, and mean number of flowers per cluster were analyzed after Griffing (1956, Aust. J. Biology 9: 463-493), method 2, model 1. Both general and specific combining abilities (GCA and SCA) were significant for the four traits. Negative unidirectional dominance was detected for fruit weight and shelf life, while bidirectional dominance was detected for fruit shape and mean number of flowers per cluster. SCA was greater than GCA for shelf life, so nonadditive effects predominantly accounted for this trait. In the heterozygous state, rin had smaller mean effects than nor. Wild accessions were able to prolong shelf life per se, and in crosses to the cultivated variety. The cross between the homozygote for nor and LA722 yielded the longest shelf life among hybrids
