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1.
Genet Mol Res ; 12(1): 381-9, 2013 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-23420362

RESUMEN

Acyl sugars are allelochemicals present at high concentrations in leaves of accessions of the wild tomato Solanum pennellii; they confer resistance to a large number of arthropod pests, including the tomato pinworm, Tuta absoluta (Lepidoptera, Gelechiidae). Accession 'LA716', with high contents of acyl sugars in the leaves, was used as a source of resistance to start a genetic breeding program of processing cultivated tomato, S. lycopersicum. We selected plants of the F2 generation of an interspecific cross (S. lycopersicum cv. 'Redenção' x S. pennellii 'LA716') for extremes of concentrations (high and low) of acyl sugars in the leaves and evaluated the resistance of selected genotypes to the tomato pinworm, compared with plants of the parental and F1 generations. The concentrations of acyl sugars present in the genotypes selected for high contents were close to those of S. pennellii 'LA 716', while the genotypes with low concentrations of acyl sugars were close to cultivar 'Redenção'. The F1 hybrid ('Redenção' x 'LA716') had intermediate concentrations of acyl sugars, but was closer to Redenção, indicating that the inheritance of this type of character is due to a recessive major gene, along with minor genes with additive effects. There was a direct association between high contents of acyl sugars and non-preference for oviposition and suppression of larval development, indicating that the allelochemical acts through mechanisms of non-preference for oviposition and through antibiosis. Genotypes with high contents of acyl sugars were more effective in reducing the damage caused by the tomato pinworm. Genotypes RVTA-2010pl#94 and RVTA-2010pl#31, selected for high contents of acyl sugars, showed a good level of resistance to T. absoluta, similar to the wild genotype LA716. These genotypes are promising for use in a breeding program for developing commercial processing tomatoes.


Asunto(s)
Carbohidratos/genética , Feromonas/genética , Feromonas/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/parasitología , Solanum lycopersicum/genética , Solanum lycopersicum/parasitología , Animales , Cruzamiento , Enterobius , Genotipo , Lepidópteros , Solanum/genética , Solanum/parasitología
2.
Braz J Biol ; 71(3): 569-75, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21881780

RESUMEN

The recently-discovered titi, Callicebus coimbrai, is endemic to the coastal Brazilian Atlantic Forest south of the São Francisco River, a region with a long tradition of deforestation. While a number of C. coimbrai populations have now been identified, little is known about basic population parameters. Considering the importance of this information for conservation planning, the population of a site in southern Sergipe (with a total area of forest of approximately 500 ha) was surveyed between April and October 2008. Standard line transect procedures were used in the four largest fragments, and additional monitoring included the use of playback broadcasts for the observation of titi groups. The presence of titis was confirmed in all the forest fragments at the site, including one of only five hectares. Two other primates - Callithrix jacchus and Cebus xanthosternos - were also recorded at the site, but were less abundant than titis. A total transect walk of 476 km provided 164 sightings of primates, the majority of which (104) were of Callicebus coimbrai. Titi groups ranged in size between two and five individuals. The most reliable estimate of overall population density, derived from the combined data set, was 12.6 individuals per km²;, although density was much higher in smaller (more disturbed) fragments. The total population of Callicebus coimbrai at the site was estimated to be at least 50 individuals, which may represent a considerable proportion of the population of the species remaining in the wild. In addition to its apparent tolerance of habitat fragmentation, densities of C. coimbrai recorded at the site compare favourably with those of other Atlantic Forest titi species.


Asunto(s)
Ecosistema , Especies en Peligro de Extinción , Pitheciidae/clasificación , Animales , Brasil , Densidad de Población , Árboles
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