Acta Agronómica

**Evaluation and selection of a protocol for Agrobacterium-mediated genetic transformation of tomato variety Unapal-Arreboles for resistance to budworm**

Se evaluó y seleccionó una metodología para la transformación genética de la variedad de tomate UNAPAL-Arreboles con el gen cry1Ab para la incorporación de resistencia al cogollero (Tuta absoluta), utilizando el sistema de Agrobacterium. Se regeneraron 59 plantas transgénicas a partir de 3.200 explantes (1.84%). La integración estable, expresión y herencia de los genes nptII y gus-intrón, se demostraron mediante análisis histoquímico y molecular en los clones To28, To33 y To47 y en la correspondiente generación T1. Sin embargo, los análisis molecular e inmunológico indicaron ausencia del gen cry1Ab sugiriendo que la secuencia de este gen se puede haber modificado.

A plant transformation methodology was selected and evaluated to incorporate the cry1Ab gene by Agrobacterium-mediate genetic transformation into tomato variety UNAPAL-Arreboles for resistance to budworm (Tuta absoluta). A total of 59 transgenic plants were regenerated from 3.200 explants (1.84%). Histochemical gus assay and molecular analysis of three independent events To28, To33 and To47 and corresponding T1 derived generations, demonstrate the stable integration, expression and inheritance of the nptII and gus-intron genes. However, the molecular and immunological analysis of these same clones, indicate that the cry1Ab gene is not present in the transformed plants, suggesting that the sequence of this gene may be modified as result of possible recombinant events.

Morphologic characterization of wild accesions of guava

Se realizó la caracterización morfológica de 22 accesiones silvestres de guayaba Psidium guajava L. 14 colectadas en el municipio de Restrepo (Valle del Cauca), seis en Armenia (Quindío) y dos en Pereira (Risaralda). Se utilizaron 12 descriptores cuantitativos y 10 cualitativos de tallo, hojas y frutos; el análisis de agrupamiento se hizo mediante el coeficiente de Dice-Nei-Li y el promedio aritmético no ponderado (UPGMA). La mayor variabilidad se halló en los descriptores peso de la pulpa (CV = 55.92%), peso (CV = 45.23%), y acidez del fruto (CV = 44.75%). El análisis de agrupamientos con base en caracteres cuantitativos permitió establecer cuatro grupos: las accesiones del grupo A (Armenia), presentaron valores promedio de los descriptores de la calidad del fruto (grados Brix, acidez del fruto y relación grados Brix/acidez) y valores altos de contenido de pulpa. La mayoría de accesiones del grupo C (Restrepo) tuvieron altos valores de calidad del fruto y bajo contenido de pulpa. El grupo B, constituido por accesiones de Armenia y Pereira, se diferenció por valores bajos en los descriptores de rendimiento del fruto (peso del fruto, de la pulpa y diámetro de la cavidad seminal). Las accesiones del grupo D (Restrepo) mostraron valores promedios en calidad y rendimiento del fruto. Los descriptores cuantitativos se reunieron en tres variables sintéticas para rendimiento y calidad del fruto que representaron 76.86% de la variabilidad total.

Quantitative and qualitative morphologic characterization of 22 wild accessions of guava Psidium guajava L. collected in Restrepo (Valle del Cauca), Armenia (Quindío) and Pereira (Risaralda) was done. Twelve (12) quantitative and ten (10) qualitative descriptors of stem, leaves and fruits were used. The Dice- Nei Li coefficient and the UPGMA was used for the cluster analysis. Dendrograms and principal components analysis were used. The highest variability was associated with fruit descriptors, pulp weight (CV = 55.92 %), fruit weight (CV = 45.23 %) and acidity (CV = 44.75 %). The joining analysis using quantitative characters allowed forming four groups: accessions from group A (Armenia) showed mean values of fruit quality descriptors (Brix grades, fruit sourness and relation between Brix grades/sourness) and high pulp content. The majority accessions of group C (Restrepo) had high quality fruit values, and low pulp content. Group B, formed by accessions from Armenia and Pereira, was differentiated by low yield descriptors values (weight fruit, pulp and seminal cavity diameter). Accessions from group D (Restrepo) showed mean values in quality and fruit yield. Quantitative descriptors were joined in three synthetic variables for yield and quality fruit that represented 76.86% of the total variation.

Spatial and daily variability of soil moisture content in three agroforestry systems

En seis puntos de tres transectos (102 m) paralelos (9 m) en tres sistemas de uso del terreno (Quesungual menor de dos años, SAQ<2, Tradicional de Tala y Quema, TQ y Bosque Secundario, BS) se tomaron muestras de suelo a cuatro profundidades (0-5 cm, 5-10 cm, 10-20 cm y 20 a 40 cm) y tres horas (09, 11 y 15) durante 9 días. Se modeló el análisis estructural de la variación de los parámetros humedad volumétrica, densidad aparente, carbono orgánico, arena y arcilla. El coeficiente de variación de los parámetros evaluados presentó rangos para densidad aparente (0.76 y 15.1%), carbono orgánico (30.4 y 54.3%), humedad volumétrica (9.5 y 23.5%), arena (12.8 y 22.5%) y arcilla (14.0 y 29.2%). En los análisis geoestadísticos el componente al azar de la dependencia espacial predominó sobre el efecto pepita (nugget). Con las funciones de los semivariogramas estructurados para cada variable se generaron mapas de contorno interpolados a escala fina los cuales mostraron heterogeneidad en las propiedades evaluadas. La autocorrelación de Morán (I) indicó que rangos de muestreo menores a 9 m podrían ser adecuados para detectar la estructura espacial de la variable humedad volumétrica.

The objective of this study was to determine the level of soil spatial variability in an area consisting of the land uses: Quesungual slash and mulch agroforestry system with less than two years (QSMAS<2), Slash-and-burn traditional system (SB) and Secondary forest (SF). Soil samples were taken in three parallel transects of 102 m in length, separated 9 meters. The profile was sampled in the depths from 0 to 5 cm, 5 to 10 cm, 10 to 20 cm and 20 to 40 cm in 6 points (09, 11 am and 05) during 9 days. Coefficient of variation for soil properties varied for bulk density (0.76 and 15.1%), organic carbon (30.4 and 54.3%), volumetric moisture (9.5 and 23.5%), sand (12.8 and 22.5%) and clay (14.0 and 29.2%). The geo-statistical analysis showed that the random component of the spatial dependence was predominant over the nugget effect. The functions of semivariograms, structured for each variable were used to generate maps of interpolated contours at a fine scale. The Moran (I) autocorrelation indicated that sampling ranges less than 9 m would be adequate to detect spatial structure of the volumetric moisture variable.

Livestock productive potential in the hillside areas of Cauca Valley, Colombia

Se evaluó el potencial productivo-PPS en suelos volcánicos de ladera de tres fincas lecheras (Nogales, Refugio y Horizonte) en Bolívar, Valle del Cauca, utilizando un indicador mixto de propiedades (físicas, químicas y de actividad biológica del suelo), conductividad térmica y el efecto de manejo con los índices de Compactación (IC) y Fertilidad (IF). Se utilizó un diseño completamente al azar con tres tratamientos y cinco repeticiones de acuerdo con zonas homogéneas de humedad edáfica. IC fue moderado en todos los casos y PPS fue medio en las tres fincas no obstante el IF fuera alto en Nogales y moderado en Refugio y Horizonte. La correlación lineal múltiple entre parámetros indicó que IC e IF influyeron aproximadamente en un 70 % sobre PPS.

The productive potential (PP) of three dairy farms with volcanic soils, located in hillside areas of Bolivar, Valle del Cauca, Colombia, was evaluated using a mixed indicator that assessed the soil's physical and chemical properties as well as its biological activity, including a new characteristic-thermal conductivity sensitive to soil quality. The effect of management on soil fertility and compaction was also assessed using two new soil indicators: compaction and fertility. A completely randomized design was used, with farms corresponding to the treatments. The replicates on each farm were carried out according to homogeneous areas of soil moisture. The results for each indicator agreed with the individual analysis of soil properties. Compaction was moderate in all cases and PP was intermediate on the three farms, although soil fertility was high in Nogales and moderate in Refugio and Horizonte. The multiple linear correlation between these parameters indicated that compaction and fertility accounted for approximately 70% of the PP.

Atributos químicos do solo e ocorrência de fungos micorrízicos sob áreas de pastagem e sistema agroflorestal, Brasil

Este trabalho teve como objetivo caracterizar alguns atributos químicos do solo e avaliar a comunidade de fungos micorrízicos arbusculares (FMAs) em uma área de pastagem e um sistema agroflorestal (SAF). A área de estudo está localizada na "Fazendinha Agroecológica do Km 47", 22° 45'S, 43° 41'W, no município de Seropédica, Rio de Janeiro, Brasil. Foram coletadas amostras de solo na profundidade de 0-5 cm e quantificados os teores de carbono orgânico total (COT), Ca, Mg, pH, P e K. Os FMAs foram quantificados e posteriormente identificados. Os resultados encontrados foram analisados como delineamento inteiramente casualizado, com aplicação do teste F. Verificaram-se valores estatisticamente maiores de COT, Ca, Mg e K no SAF, assim como o maior número de esporos de fungos micorrízicos. Observou-se uma baixa diversidade de espécies de FMAs, sendo que Glomus macrocarpum e Acaulospora scrobiculata foram as espécies dominantes nas duas áreas. O manejo do solo pode ter influenciado no menor número de esporos de FMAs encontrados sob pastagem. Por meio da análise de componentes principais foi possível separar as duas áreas avaliadas, sendo o comportamento semelhante ao verificado na análise univariada.

This study had as objective characterize the chemical attributes of soil and to evaluate the community of arbuscular mycorrhizal fungi (AMFs) in a pasture area and agroforest system (AFS). The area this study is located in the Agroecological Farm, 22° 45'S, 43° 41'W, in the Seropédica, Rio de Janeiro State, Brazil. The soil samples were taken in depth of 0-5 cm and quantified the tenors of total organic carbon (TOC), Ca, Mg, pH, P and K. They were counted and identified the spores of FMAs. The found results were analyzed as design entirely casuality, with application of the test F. Verified statistically higher values of COT, Ca, Mg and K in AFS, as well as the largest number of spores of mycorrhizal fungi. One was observed lowers diversity of species of FMAs, and Glomus macrocarpum and Acaulospora scrobiculata were the dominant species in the two areas. The management of the soil might have influenced in the smallest number of spores of FMAs found under pasture. Through the analysis of main components it was possible to separate the two appraised areas, being the behavior similar to the verified in the univariate analysis.

Importance of habitat heterogeneity for ant biodiversity in the Colombian Andes

Entre marzo y octubre de 2002 se compararon los ensamblajes de hormigas que forrajean en el suelo en un sistema no manejado (reserva natural El Ciprés) y en algunas fincas vecinas. En dos transectos de 100 m se instalaron estaciones de muestreo cada 10 m con trampa de caída (pitfall) y cebo de atún epígeo durante 880 h y 92 días respectivamente. En 1471 eventos de captura se determinaron 68 especies distribuidas en 26 géneros y 8 subfamilias. En el sistema silvopastoril- guayaba y en monocultivo de granadilla (Passiflora ligularis) dominaron las especies de hormigas mientras que la distribución fue más equitativa en los usos del terreno con estructura vegetal más compleja (bosque, café, sucesión temprana y banco de forrajes). El sistema silvopastoril-guayaba fue el más rico en especies (31) seguido por café (30) y por el bosque y la sucesión temprana (29). El flujo de especies fue alto en bosque, café y sucesión temprana, indicando que la calidad de la matriz es factor importante para el mantenimiento de la biodiversidad.

In order to compare the ant assamblages in the Natural Reserve El Ciprés (Valle- Colombia) and its neighboring farms, periodical ant sampling was carried out between March and October 2002. Each site had two transects of 100m with 10 sampling points. Each sampling point contained a pitfall trap and epigeal tuna bait established for 880 h and 92 days, respectively. In addition, the vegetal structure of each place was characterised. A total of 1471 ants were collected representing 68 species in 26 genera and 8 subfamilies. Two agricultural systems, the silvopastoral guava and passion fruit (Passiflora ligularis) monoculture, typically presented ant species that over numbered other species whereas sites with more complex vegetation structure (i.e. forest, coffee, early succession and fodder banks) had a more equitable distribution for the ant species. In terms of ant richness, the guava system was the richest (31 spp.) followed by coffee (29 spp.) and forest and early succession with 28 spp., each. The latter systems were responsible for a high turn over of species, indicating that the quality of the matrix is an important issue for the biodiversity of ant species.

Evaluation of cuban hemp, nut sedge, johnson grass and herb of grace extracts in weed control

En experimentos completamente al azar en condiciones de laboratorio y campo, en Palmira, Valle del Cauca, se evaluó el efecto de extractos de Macrophylla furcraea Baker (fique), Cyperus rotundus L (coquito), Sorghum bicolor L (sorgo), y Ruta graveolens L (ruda) sobre la germinación de semillas de las arvenses Bidens pilosa L (papunga) y Amaranthus dubius Mart (bledo) y del cilantro Coriandrum sativum L. Se obtuvieron los extractos por el método Soxhlet, utilizando agua, etanol y cloroformo como solventes. Los extractos obtenidos se evaluaron en tres diluciones (0, 5 y 10 %) en pruebas de germinación de semillas de las arvenses y del cultivo. Se emplearon tres repeticiones de 50 semillas cada una y el testigo se regó con agua destilada. Los extractos etanólicos y clorofórmicos de coquito y fique en las diluciones al 5 y 10 % presentaron el mayor efecto inhibitorio en la germinación a los 21 días. El ensayo de campo demostró el efecto inhibitorio de los extractos etanólicos de fique y coquito en la emergencia de las semillas del cilantro. El análisis de metabolitos secundarios comprobó la presencia de compuestos reportados como altamente tóxicos en fique y en menor cantidad en coquito, aunque los extractos de éste fueron los que más inhibieron la germinación.

The objective of this work was to evaluate the effect of the extracts of the species Macrophylla furcraea Baker (cuban hemp), Cyperus rotundus L (nut sedge), Sorghum bicolor L (johnson grass) and Ruta graveolens L (herb of grace) on seed germination of two weeds and one crop. The extracts were obtained by the Soxhlet method, using water, ethanol and chloroform as solvents. Each extract was evaluated in three dilutions (0, 5 and 10 % v/v) and was applied to Bidens pilosa L (spanish needle), Amaranthus dubius Mart (spleen amaranth) and Coriandrum sativum L (coriander) seeds. Three replications of 50 seeds each one were used and the control was watered only with destilled water. The results showed that the ethanolics and chlorofórmics extracts of nut sedge and cuban hemp at two evaluated dilutions presented high inhibiting effect on the seed germination of the three species at 21 days. The field test verified the inhibiting effect on seed germination of the ethanolics extracts of cuban hemp and nut sedge on coriander. The secondary metabolites test showed the presence of great amount of compounds reported like highly toxic in fique and in smaller amounts in coquito although this specie inhibited the seed germination highly.

Mass selection by weight and coloration in red tilapia

Para evaluar la efectividad de la selección masal por color y peso se analizaron dos generaciones (G1 y G2) de alevinos de tilapia roja Oreochromis sp. De 40.000 larvas a la sexta semana se eliminaron los alevinos manchados y blancos y a las 14 semanas se separaron por sexos. Se midió el peso (g), la longitud total (cm), la altura (cm) y el ancho (cm) de 150 individuos a las 6, 14 y 24 semanas de edad. En la semana 24 se escogieron 150 machos y 450 hembras con las coloraciones deseables y mayor peso. La selección resultó efectiva para coloración en G2, puesto que la proporción de individuos rojos se incrementó en 15% con respecto a los testigos. Entre generaciones (G1 y G2) el efecto de la selección fue positivo, debido a que la proporción de rojos se incrementó de 64% a 84% y se redujo la de manchados de 31% a 13%. En ambas generaciones los machos fueron significativamente más pesados que las hembras. Se encontraron notables diferencias entre generaciones para peso y talla, puesto que los selectos superaron al control en 27% y 8% (G1) y en 22% y 11% (G2) para el peso y la talla, respectivamente.

In order to evaluate the effectiveness of mass selection by color and weight, two generations (G1 y G2) of red tilapia Oreochromis sp. were analyzed. 40000 larvae were used, at the sixth week fries with black spots and white were eliminated, and at week 14, the fishes were separated by sex. The weight (g), length, height and width (cm) were measured in a sample of 150 individuals at 6, 14 and 24 weeks. At week 24, the best 150 males and 450 females with desirable colorations and higher weight were chosen. The selection was effective for coloration in G2, because proportion of red individuals increased in 15% compared to the control. The effect of the selection between generations (G1 y G2) was positive because proportion of red fries increased from 64% to 84%, and the spotted ones were reduced from 31% to 13%. In both generations males were significantly weighted than the females. For weight and size, significant differences between generations were found due to the fact that the selected ones were over the control on 27% and 8% (G1) and 22% and 11% (G2) for weight and size respectively.