Lime sulfur to control citrus flat mite and its interactions with the entomopathogenic fungus Lecanicillium muscarium

Lime sulfur is one of the few products indicated to control Brevipalpus yothersi in Brazilian organic citrus orchards. Other strategies, such as the use of entomopathogenic fungi should be evaluated, and Lecanicillium muscarium is one of the basic choices for pest management. Knowledge of the interactions between lime sulfur and this entomopathogen is critical for developing control strategies. With this goal, it was conducted the toxicological characterization of lime sulfur to B. yothersi and the compatibility evaluation with L. muscarium. Finally, the effects of L. muscarium and lime sulfur mixtures on B. yothersi control were evaluated. Product evaluation for B. yothersi was done through direct and residual contact bioassay, and different concentrations of lime sulfur mixed in potato dextrose agar culture medium were used to evaluate compatibility with L. muscarium. Lime sulfur was effective against adults of B. yothersi and caused eggs unviability of up to 71.0%, at a dose of 80 L per 2,000 L of H2O. The lethal concentration (LC50 and LC99) of lime sulfur estimated for mite adults were 246.62 and 858.5 µg of sulfur per mL of H2O (ppm a.i.). Lime sulfur concentrations of 180 to 560 ppm a.i. showed promise for use in combination with L. muscarium. However, concentrations of 1,000 and 5,600 ppm significantly reduced colony size and the number of spores/colony. The mixture of 100 and 180 ppm a.i. of lime sulfur with L. muscarium (108 conidia·mL­1) was not able to reduce the lethal time of entomopathogen on B. yothersi.

Mejoramiento de la calidad del fruto por la incorporación de genes de especies silvestres en el tomate (Solanum lycopersicum L.) / Fruit quality improvement through the incorporation of wild species genes in the tomato (Solanum lycopersicum L.)

RESUMEN En el mejoramiento del tomate (Solanum lycopersicum L.) se ha logrado un incremento significativo para el rendimiento y otras características productivas en un período corto de tiempo. Como consecuencia se redujo notablemente la diversidad genética. Si bien el germoplasma silvestre se ha utilizado principalmente como fuente de genes de resistencia para enfermedades y plagas, nuestro grupo inició en la década de 1990, un programa de mejoramiento genético en tomate para mejorar la calidad del fruto con especial énfasis en incrementar la vida poscosecha y también ampliar la variabilidad genética con la incorporación de estos genes al gran cultivo. Hemos desarrollado diferentes poblaciones a partir del cruzamiento interespecífico entre el cultivar argentino Caimanta de S. lycopersicum y la accesión LA0722 de S. pimpinellifolium L. Mediante la generación de cruzamientos entre estos padres selectos y el posterior avance generacional de la selección se ha tratado de dilucidar las bases genéticas que definen la calidad del fruto. Para ello se integraron al programa de mejoramiento información obtenida de datos genómicos, posgenómicos y bioinformáticos. Al mismo tiempo hemos desarrollado cuatro nuevos cultivares con características de calidad de fruto superiores al ser comparados con híbridos comerciales. Para conservar y estudiar la diversidad del cultivo también estamos desarrollado una colección de germoplasma que en la actualidad cuenta con 162 genotipos de tomate de diferentes especies y orígenes. Además, se ha iniciado la transferencia directa de plantines a huertas urbanas y periurbanas para favorecer el acceso a semillas de estos cultivares desarrollados en instituciones públicas.

ABSTRACT The genetic improvement of tomato (Solanum lycopersicum L.) has achieved an increase for yield and other agronomic traits in a short period of time. As a consequence, genetic diversity has been notably reduced. Wild germplasm has been mostly used as a source of resistance genes for diseases and pests. Our group started in the 1990' a breeding program in tomato for improving fruit quality, with special emphasis on increasing fruit shelf life and broadening the genetic variability with the incorporation of wild genes. We have developed different populations from the interspecific cross between the Argentine cultivar Caimanta of S. lycopersicum and the accession LA0722 of S. pimpinellifolium L. Through crosses between these selected parents and the subsequent generational selection advance, we attempted to elucidate the genetic bases that underlie tomato fruit quality. To do that, we use state-of-the-art technology available in the field of genetics and breeding programs, including genomic, post-genomic and bioinformatic data. At the same time, we have developed four new cultivars with improved fruit quality traits compared to commercial hybrids. To conserve and study the tomato diversity, we have developed a germplasm collection that currently contains 162 tomato genotypes from different species and origins. In addition, we have started a direct transfer of our cultivars to urban and peri-urban community orchards to facilitate them the access to genotypes that were developed in Argentine public institutions.

Differences in volatile composition and sexual morphs in rambutan (Nephelium lappaceum L.) flowers and their effect in the Apis mellifera L. (Hymenoptera, Apidae) attraction

ABSTRACT We studied the volatile composition and sexual morphs of Nephelium lappaceum flowers from two orchards, and investigated the choice behavior of the honey bee, Apis mellifera toward the floral extracts from both locations. Our results showed significant differences in chemical composition and sexual morphs; only the hermaphrodite flowers from the Herradero orchard produced limonene and α-pinene and had longer peduncle and sepal than flowers from the Metapa orchard; on the other hand, the hermaphrodite flowers from the Metapa orchard had longer gynoecium. In the behavioral experiment the extracts from the Herradero orchard seemed to give A. mellifera foragers better cues for orientation to food sources, perhaps due to the presence of limonene and α-pinene, which are absent in the samples from Metapa. Such differences in both orchards could affect pollinator attraction and ultimately seed set and productivity.

Anastrepha aczeli Blanchard and Anastrepha similisGreene (Diptera: Tephritidae) in Minas Gerais, Brazil / Anastrepha aczeli Blanchard e Anastrepha similis Greene (Diptera: Tephritidae) em Minas Gerais, Brasil

The occurrence of Anastrepha aczeliBlanchard and Anastrepha similisGreene (Diptera: Tephritidae) is recorded in the state of Minas Gerais, Brazil. Specimens of A. aczeliwere found in traps placed in orchards of acerola, Malpighia emarginataDC (Malpighiaceae), and citrus, Citrus sinensis(L.) Osbeck (Rutaceae), and A. similiswas obtained in traps placed in citrus orchards located in the county of Bambuí, MG, Brazil.

As ocorrências de Anastrepha aczeliBlanchard e Anastrepha similisGreene (Diptera: Tephritidae) são registradas pela primeira vez no estado de Minas Gerais, Brasil. Os espécimes de A. aczeliforam encontrados em armadilhas montadas em pomares de acerola, Malpighia emarginataDC (Malpighiaceae), e citros, Citrus sinensis(L.) Osbeck (Rutaceae), e os de A. similisobtidos em armadilhas montadas em pomares de citros, em pomares instalados no município de Bambuí, MG, Brasil.

Production of Amylase by Arthrobacter kerguelensis VL-RK_09 Isolated from Mango Orchards.

Objectives: To optimize the cultural parameters for improved production of amylase by Arthrobacter kerguelensis VL-RK_09 isolated from Mango orchards of Vissannapet, Krishna District, A.P., India. Methods: The strain A. kerguelensis was screened initially for amylase production on Inorganic salts starch agar medium (ISP-4). The enzyme assay was performed as per the procedure described by Bernfield (1955). One amylase unit equals to that amount of enzyme needed to release 1 mg of reducing sugar (maltose as standard) for 15 min at 37°C. Attempts were also made to optimize cultural parameters such as pH, temperature, carbon and nitrogen sources affecting the production of amylase by the strain. Results: Maximal yields of amylase were recorded after 4 days of incubation in Inorganic salts starch medium with initial pH 7.0 and temperature 35°C. ISP-4 broth amended with sorghum flour (2%) and yeast extract (0.5%) with initial pH 7.0 inoculated with Arthrobacter kerguelensis VLRK_ 09 and incubated at 30°C for 96 h resulted in improved production of amylase from initial 4.0 U to 10.4 U/mL. Conclusion: This is the first report on the production and optimization of amylase by A. kerguelensis and further studies on purification and characterization of the enzyme are in progress.

Study of Host-Parasite Relationship among Loranthaceae Flowering Shrubs Myrmecophytic Fruit Trees-Ants in Logbessou District, Cameroon.

The objective of this study is host-parasite relationship among Loranthaceae flowering shrubs, Myrmecophytic fruit trees and ants. The study was conducted in 2009 in the garden plots and orchards of houses in the Logbessou district of Douala, Cameroon. We inventoried a total of 141 myrmecophytic fruit trees (diameter ≤ 45 cm) of which 95 (67.3%) were parasitized by flowering-shrub epiphytes (Loranthaceae). These trees belong to 14 species, 11 genera and 8 families. Among the eight species of ants inventoried on the trees, two were arboreal-dwelling and six were ground-dwelling, arboreal-foraging species. They belonged to two sub-families: the Formicinae, which were mostly represented by two genera, Camponotus and Paratrechina; and the Myrmicinae, which were more abundant (87.5%). The ants nested in the domatia of myrmecophyte hosts or hollow branches, trunks and dead suckers of Loranthaceae. Crematogaster was the most frequent genus and dominant ant on all of the parasitized host trees.