José Francisco Martins Pereira

Phenolic Composition in Different Genotypes of Guabiju Fruits (Myrcianthes pungens) and Their Potential as Antioxidant and Antichemotactic Agents

Fruits of Myrcianthes pungens Berg. Legr. (Myrtaceae), known as guabiju, are widely consumed fresh as well as dried, processed into jam, marmalade, and juices. In this study, chemical composition and antichemotactic and antioxidant activities of fruits from a wild type (GB) and 2 genotypes, PL2 and PL1, of guabiju were investigated. Total anthocyanins for the genotypes ranged from 334 to 531 mg/100 g dry weight (dwt). Total flavonoids and polyphenols ranged from 79.8 to 154 mg/100 g and 2438 to 4613 mg/100 g (dwt), respectively. A reversed phase liquid chromatography method with photodiode array detection was used to determine chemical profiles of the main anthocyanins found in the extracts. An HPLC method for the quantification of flavonoids is proposed, providing a simple procedure with rapid sample preparation. All samples contained 5 identical anthocyanidins, distributed differently, with cyanidin as the main compound. Identified flavonoids were quercitrin, hyperoside, and isoquercitrin; their relative amounts varied among the extracts. The antioxidant activity of guabiju methanolic extract was comparable to that of Trolox, and at a test concentration of 0.25 mg/mL, GB and PL2 activities were higher than those exhibited by Trolox. Total dry extracts of guabiju exhibited greater inhibition of chemotaxis at a concentration of 4 μg/mL, except for GBH (wild-type hydrolyzed extract) which already presented high values at a concentration of 2 μg/mL. These results suggest that the consumption of this fruit, rich in polyphenols, may be beneficial to human health. Practical Application: The paper is the first attempt on the improvement of this native fruit, since it is widely consumed regularly as part of the South American diet. The content of phenolic compounds demonstrates that consumption of guabiju would be beneficial to human health. Differences among samples, originating from open pollination of plants growing on the same site, lead to the conclusion that improvements can be made in the chemical composition and beneficial activity of guabiju fruits by simply selecting genotypes for these characteristics among open-pollinated seedlings.

Frugivorous Flies (Diptera: Tephritidae, Lonchaeidae), Their Host Plants, and Associated Parasitoids in the Extreme North of Amapá State, Brazil

Abstract We conducted a survey of frugivorous flies (Diptera: Tephritidae and Lonchaeidae), their host plants, and associated parasitoids in the extreme north of Amapá State, Brazil. Fruit were collected from various plant species between May 2011 and Jul 2013. In total, 218 fruit samples were collected (3,915 fruits, 115.6 kg), from 33 plant species (12 native and 21 introduced) in 22 families. Infestation by fruit flies was observed in 69 samples, representing 17 plant species in 13 families. In total, 3,480 puparia were obtained, from which emerged specimens of Anastrepha Schiner (6 species; Tephritidae), Neosilba McAlpine (4 species; Lonchaeidae), and Bactrocera carambolae Drew & Hancock (Tephritidae), as well as wasp parasitoids in the family Braconidae (3 species). This work adds new records of frugivorous flies in the studied area and establishes new relationships between species of frugivorous flies and host plants in the Brazilian Amazon.

Multivariate analysis applied to the study of the relationship between soil and plant properties in a peach orchard

In the State of Rio Grande do Sul, the municipality of Pelotas is responsible for 90 % of peach production due to its suitable climate and soil conditions. However, there is the need for new studies that aim at improved fruit quality and increased yield. The aim of this study was to evaluate the relationship that exists between soil physical properties and properties in the peach plant in the years 2010 and 2011 by the technique of multivariate canonical correlation. The experiment was conducted in a peach orchard located in the municipality of Morro Redondo, RS, Brazil, where an experimental grid of 101 plants was established. In a trench dug beside each one of the 101 plants, soil samples were collected to determine silt, clay, and sand contents, soil density, total porosity, macroporosity, microporosity, and volumetric water content in the 0.00-0.10 and 0.10-0.20 m layers, as well as the depth of the A horizon. In each plant and in each year, the following properties were assessed: trunk diameter, fruit size and number of fruits per plant, average weight of the fruit per plant, fruit pulp firmness, Brix content, and yield from the orchard. Exploratory analysis of the data was undertaken by descriptive statistics, and the relationships between the physical properties of the soil and of the plant were assessed by canonical correlation analysis. The results showed that the clay and microporosity variables were those that exhibited the highest coefficients of canonical cross-loading with the plant properties in the soil layers assessed, and that the variable of mean weight of the fruit per plant was that which had the highest coefficients of canonical loading within the plant group for the two years assessed.

Web blight (Thanatephorus cucumeris): a new disease on leaves of okra plants

Arq. Inst. Biol., v.84, 1-5, e0252016, 2017 ABSTRACT: In an experiment on organic production of okra (Abelmoschus esculentus (L.) Moench) that was carried out from September 2013 to January 2014, in Manaus, Amazonas state, Brazil, we observed large chlorotic, necrotic, helical, discontinuous, dark or light-brown lesions with partial detachment of the injured area on the adaxial surface of leaves located in the median and basal portions of the plants. A whitish mycelium mantle covers the lesions on the leaves at the abaxial surface at high moisture conditions. Using morphological characteristics, Koch’s postulates, and phylogenetic analyses of the ITS-5.8S rDNA region, we identified that the fungus causing the lesions on the okra leaves was Thanatephorus cucumeris (Frank) Donk (asexual stage of Rhizoctonia solani Kuhn of the anastomosis group AG-1 ID). This is the first report of T. cucumeris causing web blight on okra in Brazil, and probably in the world. So far, T. cucumeris was described on okra only on post-harvest pods rotting and seedlings’ damping off.

AGROCLIMATIC ZONING OF EUROPEAN AND ASIAN PEAR CULTIVARS WITH POTENTIAL FOR COMMERCIAL PLANTING IN SOUTHERN BRAZIL

A pera esta entre as frutas de maior interesse comercial no mundo e e a fruta mais importada pelo Brasil. A producao brasileira e muito pequena, e a qualidade da fruta nao tem padrao comercial adequado, em funcao da falta de adaptacao das peras de qualidade as condicoes edafoclimaticas brasileiras. O sucesso da cultura no Pais, entre outros fatores, pode estar associado a escolha das cultivares comerciais, polinizadoras e porta-enxertos mais bem adaptados as condicoes edafoclimaticas locais, dependendo, portanto, das indicacoes de um zoneamento agricola. Assim, o objetivo deste estudo foi identificar, na regiao Sul do Brasil, zonas climaticas homogeneas com potencial para plantios comerciais de pereiras europeias e asiaticas, por meio de estudos de riscos climaticos. As regioes foram delimitadas pela disponibilidade estacional de horas de frio (<7,2 oC) acumuladas no periodo entre maio e setembro, e pelo risco mensal de ocorrencia de deficit hidrico. A analise permitiu o reconhecimento de quatro zonas homogeneas para producao comercial de peras na regiao Sul.

Potential of Amazonian isolates of Metarhizium to control immatures of Bactrocera carambolae (Diptera: Tephritidae)

Summary This study shows the potential of Amazonian isolates of Metarhizium Sorokin to control immatures of Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae), a quarantine pest present in Brazil. Our results reveal the effectiveness of an isolate of Metarhizium anisopliae (Metsch.) Sorokin to control immatures of B. carambolae, suggesting the potential for direct application of this isolate onto the soil to reduce populations of the pest.