ABSTRACT. Bacterial canker caused by Clavibacter michiganensis subspecies michiganensis (Cmm) has been a threat to tomato production in Uruguay for several years. In this study, 39 Cmm strains were collected from several outbreaks and production areas in Uruguay, and were identified by molecular assays and pathogenicity tests on a susceptible cultivar of tomato. In addition, a TaqMan assay targeting a putative two-component system sensor kinase gene demonstrated good specificity with all strains tested and gave no false negative results.

RESUMEN. El cancro bacteriano del tomate causado por Clavibacter michiganensis subsp. michiganensis (Cmm) es una de las enfermedades más importantes del cultivo en Uruguay. Su control se basa en el uso de semillas libres del patógeno y la prevención de su diseminación mediante labores. El objetivo de este trabajo fue comparar productos desinfectantes para evitar la trasmisión Cmm mediante tijeras. En un experimento las tijeras fueron sumergidas en una solución bacteriana y en otro utilizadas en plantas enfermas.

RESUMEN. Los carotenoides y la vitamina C son componentes importantes de la calidad nutricional y organoléptica en los frutos cítricos. Los frutos de pomelo rojo deben su coloración a la presencia de licopeno, un caroteno lineal de color rojo, tanto en la piel como en la pulpa, una característica muy inusual en los frutos cítricos. Esta propiedad le confiere a los frutos un interés especial dada la gran actividad antioxidante de este compuesto y sus posibles beneficios para la salud. La conservación refrigerada es una práctica habitual durante la postcosecha de los frutos cítricos.

ABSTRACT. Grapefruits are highly susceptible to developing chilling injury (CI) symptoms during postharvest storage at low temperatures. The role of ethylene in the response of citrus fruits to low temperature is still controversial and whether the hormone is a defense response to cope with the cold-induced damage is not fully understood. Moreover, little is known about the ethylene signaling cascade in coldsensitive citrus fruit under chilling conditions.

ABSTRACT. Premise of the study:We developed a bioinformatic strategy to recover and assemble a chloroplast genome using data derived from low-coverage 454 GS FLX/Roche whole-genome sequencing. Methods:A comparative genomics approach was applied to obtain the complete chloroplast genome from a weedy biotype of rice from Uruguay. We also applied appropriate filters to discriminate reads representing novel DNA transfer events between the chloroplast and nuclear genomes. Results:From a set of 295,159 reads (96 Mb data), we assembled the chloroplast genome into two contigs.

ABSTRACT. The distinctive color of red grapefruits is due to lycopene, an unusual carotene in citrus. It has been observed that red ?Star Ruby? (SR) grapefruits grown inside the tree canopy develop a more intense red coloration than those exposed to higher light intensities. To investigate the effect of light on SR peel pigmentation, fruit were bagged or exposed to normal photoperiodic conditions, and changes in carotenoids, expression of carotenoid biosynthetic genes and plastid ultrastructure in the peel were analyzed.

ABSTRACT Grapefruits are widely recognized by their extreme sensitivity to develop chilling injury (CI) during postharvest storage at low temperature. Moreover, many cultivars and mutants of grapefruits exhibit important differences in both external and internal coloration, from yellow to deep red, due to a distinctive accumulation of the red carotene lycopene. Thus, in this study the genetic variability in external peel coloration of grapefruits has been used to examine the potential relationship between carotenoid content and composition, and susceptibility to CI.

ABSTRACT. Main conclusion:Differentiation of new and characteristic plastid ultrastructures during ripening of citrus fruits in both peel and pulp appears to be strongly correlated with the content and complement of carotenoids. Most of the species of the Citrus genus display a wide range in fruit colouration due to differences in car- otenoids; however, how this diversity is related and may contribute to plastid differentiation and ultrastructure is currently unknown.

ABSTRACT. The degradation of the postharvest fungicides imazalil, orthophenylphenol, and pyrimethanil was studied on Clementine mandarins during packinghouse storage for a 28 day period at 4 C. Fruits to which orthophenylphenol was applied, were treated with imazalil and pyrimethanil at doses of 1000 and 2000 mg L1, using cascade application for the later and cascade and wax for the former.