Abstract. Pear is one of the most important temperate fruit crops. Uruguay aims at producing pears of high quality to reach regional markets as well as those of the Northern Hemisphere. Nevertheless, local climate variability and soil conditions frequently pose sanitary challenges for pear production, mainly in the south of the country, where the major pear producing area is located.

Abstract: Pear flower bud necrosis (PFBN) has been observed in Uruguayan orchards affecting the productivity of the trees. Severity of the problem is highly variable across years and despite the fact that it is observed in several countries, the etiology of the disease is not always clear. To elucidate the cause of PFBN, different activities were implemented over several years:surveys of pear orchards to quantify PFBN severity, morphological and histological studies of diseased buds, and isolation of potential pathogenic microorganisms from affected tissues.

Abstract. A selection of 11 microsatellite markers (SSRs) reported for fingerprinting germplasm collections of Pyrus spp. was used to genotype a collection of cultivars and rootstocks. This set of markers included the "minimum core" established by Evans et al. (2009). Cultivars with known origin ('Williams', 'Abbé Fétel' and 'Doyenné du Comice') were included as reference accessions. The comparison was performed among 44 accessions collected from old pear plantations with different commercial origins and date of introduction to the country.

Eucalyptus dunnii Maiden produces good quality cellulose pulp, showing good frost tolerance. However, in Uru-guay, it needs more than six years to reach the reproductive stage. Genome duplication was proposed as a strategy to obtain useful variability. The application of mitosis inhibitors for chromosomal duplication, in explants growing in vitro, was evaluated. Two antimitotic agents were used:colchicine and oryzalin in different concen-trations and exposure times, in two types of explants:explants growing in vitro and pre-germinated seeds.

Este año la Jornada de Agrobiotecnología INIA tuvo como foco el combate a la mosca de la bichera. Atendiendo a la relevancia del tema, participaron en la organización de la jornada:MGAP, INAC, IPA, SUL y el Institut Pasteur de Montevideo. Acceda a las presentaciones:http://inia.uy/estaciones-experimentales/direcciones-regionales/inia-las-brujas/XII-Jornada-de-Agrobiotecnologia-INIA-

El género Paspalum comprende un alto número de especies que aportan buena producción y calidad como forrajeras durante la época estival. En un contexto de cambio climático y ante la oportunidad de aumentar el uso de especies C4 como forrajeras, INIA se encuentra trabajando sobre estrategias para generar resistencia a la "enfermedad azucarada" y así favorecer la formación y desarrollo de semilla en especies de este género.

Rice blast caused by Pyricularia oryzae is a major rice disease worldwide. Despite the detailed knowledge on major resistance genes available to date, little is known about how these genes interact with quantitative blast resistance loci and with the genetic background. Knowledge on these interactions is crucial for assessing the usefulness of introgressed resistance loci in breeding germplasm. Our goal was to identify quantitative trait loci (QTL) for blast resistance in rice breeding populations and to describe how they interact among each other and with the genetic background.

Soil microbial communities play critical roles in maintaining natural ecosystems such as the Campos biome grasslands of southern South America. These grasslands are characterized by a high diversity of soils, low available phosphorus (P) and limited water holding capacity. This work aimed to describe prokaryotic communities associated with different soil types and to examine the relationship among these soil communities, the parent material and the soil nutrient status. Five Uruguayan soils with different parent material and nutrient status, under natural grasslands, were compared.

ABSTRACT. BACKGROUND AND AIMS:The Mediterranean-type forest of central Chile is considered a 'biodiversity hotspot' and a relic of a wider ancient distribution produced by past climatic oscillations. Nothofagus macrocarpa, commonly known as 'roble de Santiago', is a threatened palaeoendemic of this forest, poorly represented in the protected area system. This tree has been repeatedly misidentified as the sister species N. obliqua, which has affected its recognition and protection. Only a few populations of N.

ABSTRACT. BACKGROUND AND AIMS: The Mediterranean-type forest of central Chile is considered a 'biodiversity hotspot' and a relic of a wider ancient distribution produced by past climatic oscillations. Nothofagus macrocarpa, commonly known as 'roble de Santiago', is a threatened palaeoendemic of this forest, poorly represented in the protected area system. This tree has been repeatedly misidentified as the sister species N. obliqua, which has affected its recognition and protection. Only a few populations of N.