El guayabo del país o feijoa (Acca sellowiana (Berg) Burret- Rutaceae) se explota de manera comercial en varios países, por lo que ha despertado el interés de los programas de mejoramiento nacionales a fin de identificar los que se adapten a la explotación comercial. En este trabajo se evaluó el comportamiento de frutos de 14 materiales genéticos durante la conservación por 8 y 15 días a 5 ± 1 ºC. Se evaluaron la firmeza de la pulpa, que fue mayor en los materiales 171 y 191, disminuyendo entre un 10-38 % y entre 30-63 % luego de 8 y 15 días a 5 ± 1 ºC respectivamente. También se midieron los sólidos solubles totales (SST) que se mantuvieron constantes con el transcurso de la conservación, siendo mayores en los materiales 84 y 246. El contenido de ácido ascórbico (AA) disminuyó con el transcurso del tiempo, siendo mayor en el material 191, con 48,92 ± 1,74 mg AA/100 g peso fresco (PF). También se encontraron diferencias en los polifenoles totales (PT) donde los valores estuvieron entre 359,04 ± 4,12 y 196,5 ± 8,37 mg equivalentes de ácido gálico/ 100 g PF en cosecha, siendo mayores en los materiales 171, 191 y 204. La capacidad antioxidante total (CAT), al depender directamente de los componentes anteriores, también reflejó diferencias entre materiales, siendo mayor en el 44, 60, 171, 191 y 204. Tanto los PT como la CAT disminuyeron con el transcurso de la conservación. Los resultados obtenidos evidencian diferencias entre los materiales donde los de mayor interés corresponden a los identificados con los números 171, 191 y 204.

The feijoa (Acca sellowiana (Berg) Burret- Rutaceae) is commercially exploited in several countries, which has awakened the interest of the national breeding programs in order to identify materials suitable for commercial exploitation. In this work fruit of 14 different genetic materials were evaluated during storage for 8 and 15 days at 5 ± 1 ºC, in order to identify better postharvest behavior. Flesh firmness was evaluated and it was higher in the materials 171 and 191, and declined 10-38 % after 8 days and 30-63 % after 15 days at 5 ± 1 ºC . Also total solid soluble (TSS) contents remained constant over the conservation of material being greater in 84 and 246. Ascorbic acid (AA) decreased during the storage period, the highest content corresponded to the material 191 with 48.92 ± 1.74 mg AA/ 100 g fresh weight (FW). Differences among total polyphenols (TP) were determined, with values between 359.04 ± 4.12 and 196.5 ± 8.37 mg gallic acid equivalents /100 g FW at harvest. The highest contents corresponded to materials 171, 191 and 204. Finally the total antioxidant capacity (TAC), also reflected differences between materials, since it depends directly on the previously mentioned compounds. The highest values were registered on materials identified with numbers 44, 60, 171, 191 and 204. Both, TP and TAC, decreased during the storage period. The results obtained evidence differences between the analyzed materials, where the most interesting are those identified with numbers 171, 191 and 204.

El guayabo del país [Acca sellowiana (Berg) Burret)] es una especie frutícola nativa muy apreciada por su contenido de compuestos con actividad antioxidante, polifenoles, flavonoides y vitamina C entre otros. En el presente trabajo se caracterizaron 10 materiales genéticos de los trabajos de identificación y selección de la Estación Experimental de la Facultad de Agronomía en Salto (EEFAS), Uruguay. Se determinaron el espesor de la cáscara, la firmeza de la pulpa, polifenoles totales y actividad antioxidante de frutos recolectados en tres estados de madurez (estado 1: inmaduros; estado 2: maduros y estado 3: sobremaduros). Todas las variables medidas disminuyeron con el transcurso de la madurez. Las selecciones 12, 14, 16 y 23 presentaron una cáscara más fina. La menor pérdida de firmeza se observó en las selecciones 17, 23 y 29 tanto para los frutos cosechados en el estado de madurez 1 como en el estado 2. Las selecciones 26 y 29 presentaron contenidos de polifenoles totales mayores mientras que las selecciones 14 y 26 fueron las de mayor actividad antioxidante. La actividad antioxidante y el contenido de polifenoles mostraron diferencias entre estados de madurez –donde los mayores valores correspondieron a los frutos inmaduros– y entre selecciones. Finalmente, las selecciones genéticas identificadas como 12, 14, 23 y 26 serían las más interesantes por presentar una cáscara más fina, una mejor firmeza y mayor contenido de compuestos fenólicos y actividad antioxidante.

Feijoa [Acca sellowiana (Berg) Burret] is a native species whose fruits are appreciated for their content on compounds with antioxidant activity as polyphenols, flavonoids and vitamin C among others. In this study, 10 genetic materials derived from the Experimental Station of the School of Agriculture in Salto (EEFAS), Uruguay, were characterized. Husk thickness, flesh firmness, total polyphenols and antioxidant activity were determined on fruits harvested at three maturity stages (stage 1: immature fruits; stage 2: mature fruits; stage 3: overripe fruits). All measured variables decreased with the maturity progress. Selections 12, 14, 16 and 23, presented a thinner husk. The lowest loss of firmness was observed in the selections 17, 23 and 29 for both the fruits harvested in the mature state 1, and in state 2. The higher total polyphenols content corresponded to the selections 26 and 29, while the higher antioxidant activity was found on selections 14 and 26. The antioxidant activity and polyphenol content showed differences among maturity stages –where the highest values corresponded to the immature fruit– and among selections. Finally, genetic selections identified as 12, 14, 23 and 26 would be the most interesting ones because of their thinner husk, improved firmness, and higher content of phenolic compounds and antioxidant activity.

The feijoa plants [Acca sellowiana (Berg.) Burret] is one of the most valued genetic resource plants underutilized from Uruguay and Brazil. This tree is endemic of a narrow area of South America, comprising the northeast of Uruguay and the south of Brazil. Beyond the fact that it has edible fruits, cultivation is limited to domestic scale or small orchards. The use of genetic resource plants from this species is hindered by the lack of knowledge about the diversity both in natural and cultivated stands. The goal of this research is to generate a list of descriptors in order to facilitate the characterization and evaluation of plant material for conservation, sustainable uses and the incorporation into plant breeding programs. A preliminary list with 41 morpho-phenological descriptors for leaves, flowers and fruits was elaborated and applied in situ to 204 individuals belonging to four wild populations of the northeast Uruguay. Using the Restricted maximum likelihood, variance components between populations were estimated (s²P), between plants inside populations (s²I(P)), between samples from the same individual (s²M(IP)) and their confidence intervals using a Mixed Linear Model. In order to determinate the discriminative power of quantitative variables the adopted statistical criteria consisted in the IC comparison (lower limit ICs²I(P) >upper limit ICs²M)IP)) and then the coefficient between s²I(P)/s²M(IP) was calculated. In the case of qualitative variables, the F statistical index was estimated in order to identify significant differences between individuals with the aim to establish discriminant descriptors for individuals. Discriminant variables at population level were also determined. Seven qualitative descriptors (fruit shape, sepals position, pulp color, inner skin color, skin hardness, distance classes for stigma-stamen) and eight quantitative descriptors (height, fruit diameter and weight, pulp weight, skin thickness and resistance, stigma-stamen distance and number of stamens) were validated for individual differentiation. Among studied populations 16 quantitative and 10 qualitative variables were identified.

Guayabo del país o goiaba serrana [Acca sellowiana (Berg.) Burret] es uno de los recursos fitogenéticos subutilizados más valiosos de Uruguay y Brasil. Este árbol de fruto comestible, es endémico de una estrecha región sudamericana que abarca el noreste uruguayo y sur de Brasil, donde su cultivo se limita al uso doméstico o a pequeños huertos comerciales. El uso de los materiales de la especie se ve limitado por el desconocimiento de la diversidad presente tanto en poblaciones naturales como en materiales cultivados. El objetivo de este trabajo fue la elaboración de una lista de descriptores que permita la caracterización y evaluación de los materiales para la conservación, uso sostenible e incorporación de diversidad en los programas de mejoramiento genético. Se elaboró una lista preliminar de 41 descriptores morfo-fenológicos de hoja, flor y fruto, que se aplicó in situ a 204 individuos pertenecientes a cuatro poblaciones silvestres del noreste del Uruguay. Con el método de Máxima Verosimilitud Restringida se estimaron los componentes de la varianza entre poblaciones (s²P), entre individuos dentro de poblaciones (s²I(P)), entre muestras dentro de individuo (s²M(IP)) y sus intervalos de confianza utilizando un Modelo Lineal Mixto. Para la determinación del poder discriminante de las variables cuantitativas se adoptó como criterio estadístico la comparación de IC (límite inferior ICs²I(P)>límite superior ICs²M(IP)) y se calculó la razón entre s²I(P)/s²M(IP). Para las variables cualitativas se calculó el estadístico F para la determinación de las diferencias significativas entre individuos con el objetivo de identificar descriptores discriminantes de individuos. También se determinaron las variables que discriminan poblaciones. Se validaron siete descriptores cualitativos (forma de fruto, posición de los sépalos, color de pulpa, color interno de la cáscara, dureza de cáscara, clases de distancia estigma-estambres) y ocho descriptores cuantitativos (altura, diámetro y peso de fruto, peso de pulpa, espesor y resistencia de cáscara, distancia estigma-estambres y número de estambres) para diferenciar individuos. Se encontraron 16 variables cuantitativas y 10 cualitativas discriminantes de las poblaciones estudiadas.

Este trabajo fue realizado con el objetivo de caracterizar la diversidad vegetal del campo natural del palmar de Castillos (Rocha, Uruguay), identificar diferencias en la composición botánica dentro y fuera del palmar, determinar las especies que discriminan los dos ambientes y reconocer las potencialidades de los recursos genéticos y servicios ambientales. Mediante el uso del método de muestreo punto cuadrado, aplicado de dos formas (ocho transectas largas y 40 transectas cortas) se determinó la presencia de 70 taxones. Los representantes de la familia Poaceae son el 57,1 % de los taxones, mayoritariamente perennes, con una relación C4/C3 de 1,6. Los análisis de agrupamientos y de componentes principales mostraron diferencias consistentes en la composición florística del estrato herbáceo del campo con palmas y sin palmas. Estas diferencias se atribuyen a la adaptación de las especies a condiciones de sombreado y mayor humedad del suelo, entre las principales: Stenotaphrum secundatum, Pratia hederacea, Juncus spp., Hydrocotyle bonariensis, Paspalum urvillei, Paspalum proliferum y Plantago sp. El palmar provee de bienes de uso directo como forraje, sombra y abrigo para el ganado, producción de miel y recreación activa. Se reporta la utilización de un grupo destacado de recursos fitogenéticos de uso forrajero, medicinal y ornamental.

This research was conducted to characterize plant diversity of the natural campo in the palm grove of Castillos (Rocha, Uruguay), to identify botanical composition differences inside and outside the palm grove, to determinate the species that discriminate the two environments, and to recognize the potential of genetic resources and environmental services. Using the square point sampling method in two different strategies (eight long transects and 40 short transects) the presence of 70 taxons was determined. The Poaceae family represented the 57,1 % of the taxons, mainly perennial, with a C4/C3 ratio of 1.6. The cluster and principal component analysis showed consistent differences between the floral composition in the herbaceous stratum of the campo with and without palm trees. These differences can be attributed to species adaptation to factors like shading and higher soil moisture; among the main differential: Stenotaphrum secundatum, Pratia hederacea, Juncus spp., Hydrocotyle bonariensis, Paspalum urvillei, Paspalum proliferum y Plantago sp. The palm grove offers direct use goods like forage, shade and shelter for cattle, honey production and active recreation. We also identify an important group of plant genetic resources for forage, medicinal and ornamental use.

Foram avaliados variabilidade, herdabilidade e correlações de caracteres agronômicos em uma variedade crioula de cebola (Allium cepa L.) e linhas S1derivadas após uma geração de autofecundação. Para produzir linhas S1foram selecionados bulbos por forma, cor e número de cascas. Cinquenta e uma linhas S1e a população original foram avaliados em blocos incompletos casualizados. Houve variabilidade para caracteres quantitativos e qualitativos. As linhas S1diferiram significativamente entre si, apresentando segregação transgressiva para número e comprimento de folhas, índice de bulbificação, peso e diâmetro de bulbo e conteúdo de matéria seca. As variâncias dentro das linhas S1foram maiores do que entre elas, para todos os caracteres. Cor de bulbo e número de cascas responderam à seleção. Matéria seca e sólidos solúveis foram altamente correlacionados, com herdabilidades de 52,6% e 36,1%, respectivamente. As linhas S1permitiram expressão da variação genética e identificação dos melhores genótipos para caracteres agronômicos de interesse.

This study assessed variability, heritability and correlations of agronomic traits in an onion (Allium cepa L.) landrace and derived S1lines after a single selfing generation. Bulbs used to develop S1lines were selected for shape, colour and high number of skins. Fifty-one S1lines and the original population were evaluated using an incomplete random block design. The original population and S1lines were highly diverse for quantitative and qualitative traits. S1lines were significantly different, with transgressive segregation for number and maximum leaf length, bulbing index, bulb weight, diameter, and dry matter content. Variances within S1lines were greater than among S1lines for all traits. Bulb colour and number of skins responded to selection. Heritabilities for dry matter and soluble solids were 52.6% and 36.1% respectively. Both traits were highly correlated. The development of S1lines allowed the expression of genetic variation and the identification of better genotypes for agronomic traits of interest.

A família das palmeiras (Arecaceae) é constituída por aproximadamente 3000 espécies, distribuídas principalmente nos trópicos e subtrópicos. Como fonte de uma variedade de produtos, contribuem para a economia mundial e local, e também para o modo de vida de várias pessoas. Historicamente, seu uso tem sido baseado em populações silvestres, mas também em domesticações locais. Muito poucas espécies estão submetidas a programas de melhoramento genético e são cultivadas a nível mundial. Este é o caso da palmeira de dendê (Elaeis guineensis), na qual consórcios de investimento e desenvolvimento investem altas quantias de dinheiro. Outro tipo de palmeira cultivada é a tamareira (Phoenix dactylifera), a qual foi domesticada milhares de anos atrás e cujo sucesso está baseado na exportação de produtos com reconhecimento mundial. Nesse caso, a produção está baseada em variedades tradicionais e os programas de melhoramento ainda são incipientes. Um terceiro grupo de palmeiras inclui aquelas espécies cujos produtos são obtidos e manufaturados para o desenvolvimento local. O objetivo desta revisão bibliográfica é contribuir para a análise de oportunidades e fragilidades no investimento em domesticação e programas de melhoramento das palmeiras com valor produtivo reconhecido.

The palm tree family (Arecaceae) is constituted by approximately 3000 species mainly distributed in the tropics and subtropics. As a source of a variety of products they contribute to the world and local economies, and also to peoples lifestyles. Historically their use has been based on wild populations, but also on local domestication. Very few species are subject of plant breeding programs and are cultivated in the world. This is the case of the African oil palm (Elaeis guineensis), in which investment and development consortiums invest high sums. Another kind of crop is the date palm (Phoenix dactylifera), which was domesticated thousand of years ago and whose success is based in the export of a fine product with worldwide recognition. In this case the production is based on traditional varieties and has very incipient breeding programs. A third group of palms includes those species from which products are obtained and manufactured for local development. The objective of this literature review is to contribute in the analysis of opportunities and weaknesses to investing in domestication and plant breeding programs in those palm trees with a recognized productive value.

El ajuste de la carga animal es una medida de manejo muy importante en sistemas pastoriles, debido a que determina la relación de la oferta de forraje con la demanda animal, y con ello afecta la productividad animal. Un experimento evaluó el efecto de 5,4 y 10,8 capones ha-1 en la estructura de praderas naturales sobre Litosoles negros y rojos de basalto en Uruguay. Se evaluó la disponibilidad y altura del forraje, composición de especies y diversidad florística y se identificaron especies indicadoras de los niveles de carga animal. El aumento de la carga animal disminuyó la oferta de forraje, pero no se detectaron cambios en la riqueza y diversidad de especies. La variable tipo de suelos explicó la mayoría de las diferencias en la composición botánica, mientras que la respuesta al incremento de la carga animal fue de menor magnitud. La respuesta de la vegetación frente al incremento de la carga de animales fue diferente según el tipo de suelo. En Litosoles negros el incremento de la carga provocó la sustitución de gramíneas perennes cespitosas de ciclo invernal por especies postradas, mientras que en Litosoles rojos este cambio fue menor. En los Litosoles negros, en los niveles de carga animal evaluados existen dos estados alternativos de la vegetación caracterizados por la dominancia de gramíneas cespitosas y postradas. En cambio, en los Litosoles rojos en ambas cargas dominaron especies postradas. Se identificaron 12 especies indicadoras de los niveles de carga animal, las cuales podrían ser utilizadas para evaluar la historia reciente de pastoreo. La evaluación de estas especies facilitará el desarrollo de planes de manejo y monitoreo de praderas naturales de basalto.

The stocking rate adjustment is one of the most important management tools in grasslands ecosystems, since it determines the relationship of forage offer with animal demand, and thereby affects animal production. A field experiment assessed the effect of 5.4 vs 10.8 wether ha-1 on the structure of grasslands of red and black basaltic shallow soils of Uruguay. Forage availability and height, species composition and floristic diversity were evaluated, and indicator species of stocking rate levels were identified. The increase of the stocking rate decreased the offered forage biomass, but no changes were detected in species richness and diversity. The soil type factor explained most of the botanical composition differences, while the response to stocking rates was of smallermagnitude. The vegetation response to the stocking rate increase was different between soil types. For the evaluated stocking rates, Black Lithosols showed two different vegetation states characterized one by the dominance of cool season tall grasses and the other by prostrate species. On the other hand, the botanical composition on the Red Lithosols was little affected. Twelve indicator species related to stocking rates levels were identified, which can be used as indicators of the recent history of grazing. The evaluation of this species will facilitate the development of management and monitoring plans of Basaltic grasslands.