Fruit maturation as a parameter for selection of sweet orange cultivars in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of the cultivation system in the aroma of the volatile compounds and total antioxidant activity of passion fruit

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparative study of ovule and fruit development in species of Hypolytrum and Rhynchospora (Cyperaceae, Poales)

The development of the ovule and of the fruit of Hypolytrum bullatum and H. schraderianum (Mapanioideae) and of Rhynchospora consanguinea and R. rugosa (Cyperoideae) are described. All species share anatropous, bitegmic and crassinucellate ovules, funicular obturator, megagametophyte of the Polygonum type, presence of starch grains in the mature megagametophyte, free-nuclear endosperm, Onagrad-type embryogeny, testal-tegmic seed, and a simple fruit of the achene type. Rhynchospora species have characters typical of the family: micropyle formed by the inner integument alone; 3-4-layered parietal tissue; and hard achene. Hypolytrum species differ in those characters by presenting a slightly zigzag micropyle formed by both integuments connected with the funicular obturator, 5-8-layered parietal tissue, and fibrous-spongy achene. The peculiar formation of the micropyle in Hypolytrum is a feature reported here for the first time in the family. The ontogeny provides evidence for a better understanding of the dispersal unit in Hypolytrum supporting the classification as a true achene, like that of Rhynchospora, which is characteristic of the family.

Wolbachia in Anastrepha Fruit Flies (Diptera: Tephritidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Amino Acids on Mango Yield and Fruit Quality at Submedio Sao Francisco Region, Brazil

Farmers of the Submedio Sao Francisco Region (Brazil) have been spraying amino acids on mango trees with the objective of increasing panicle length and improving fruit retention and quality. This study, done in two experiments, tested the effect of amino acids sprayings at concentrations of 0.0%; 0.02%; 0.04% and 0.06%, on mango plants, 'Tommy Atkins', on the budding phase (panicles with 5 cm), fruit set and fruit growth (5 cm diameter). They were carried out from June to October in 2003, that is the natural period for harvest in the region, and from January to May, in 2004. There were no statistical differences in the first experiment among treatments regarding panicle length and fruit production, probably due to an appropriate management of nutrition, water and plant growth regulators, besides climatic conditions, mainly temperature and solar radiation. In the second experiment, significant increments in the panicle length of 13.37%, 11.70% and 21.4% were observed with amino acids concentrations, compared to the control. Increasing amino acids doses also enhanced the number of fruits per plant, thirty days before the harvest, in 16.17%, 45.32% and 37.38%, respectively, compared to the control, but there were no significant statistical differences. Characteristics of fruit quality during storage, as weight loss, total soluble solids, total titratable acidity and pulp firmness were not significantly affected by amino acids spraying. Changes on those variables were registered as a consequence of fruit ripening. Amino acids sprays lightly delayed the evolution of skin luminosity and Hue of pulp, but the differences could not be visually identified. The concentrations of amino acids were not efficient for improving the natural concentrations of these substances in the leaves, which could be the reason for the non significant effects on the variables analyzed.

Faunal analysis of the species Anastrepha in the fruit growing complex Gaviao River, Bahia, Brazil

Besides being considered the greatest pests of fruit growing, fruit flies constitute a large obstacle to the growth of the exportation of fresh fruit. Knowledge of the structure of fruit fly communities is of great importance to the bioecological studies of these insects, but there is a lack of information about the faunistic composition of fruit flies in Brazil. The objective of this work was to analysis the composition of the species of Anastrepha, in eleven mango orchards of the fruit growing complex Gaviao River, Bahia, Brazil. These studies were done in 2004 and 2005, in Anage, Caraibas and Belo Campo town, 23 McPhail traps, which collected 798 female fruit flies from the genus Anastrepha. The structure of these communities was evaluated in each orchard by means of faunistic indexes frequency, constancy, dominance, diversity and similarity. The number of species varied from four to eight in each orchard; and the following species was recorded: Anastrepha fraterculus (Wiedemann), Anastrepha obliqua (Macquart), Anastrepha dissimilis Stone, Anastrepha amita Zucchi, Anastrepha distincta Greene, Anastrepha pickeli Lima. Anastrepha sororcula Zucchi and Anastrepha zenildae Zucchi. The most frequent and dominant species were A. fraterculus and A. obliqua. The indexes of diversity varied from 1.01 to 1.62. In general, the similarity between orchards was high (above 55.0%). We observed the formation of groups, one constituted by Frutvale, Carlan, Santa Clara and Panorama orchards; another composed of Cofet, Campo Gaviao and Ouro Verde and a third group formed by Boa Vista orchard. Barra da Onca and Arruda are distinguished from other orchards.

Soluble and bound peroxidases from papaya fruit

Soluble and bound peroxidases were isolated from the pulp of ripening papaya fruit. During papaya ripening, soluble and bound peroxidase activities increased 2.5- and 4.2-fold, respectively. Soluble peroxidase was purified 59-fold by ammonium sulphate precipitation and chromatography on Sephadex G-25, DEAE-cellulose and Sephadex G-100. Bound peroxidase was purified 140-fold by ammonium sulphate precipitation and chromatography on Sephadex G-100 and DEAE-cellulose. Polyacrylamide gel electrophoresis of the purified preparations revealed that both enzymes were highly purified by the procedures adopted. The soluble and bound forms had a Mr of 41 000 and 54 000, respectively. Soluble and bound peroxidases showed optimum activity at pH 6.0 and 5.5, respectively, and were inhibited by p-chloromercuribenzoate, iodoacetamide, N-ethylmaleimide, potassium cyanide and Fe2+. Soluble peroxidase was activated by ammonium sulphate and this activation was prevented by cyanide. © 1990.

Persistence and metabolism of fenthion in orange fruit

The persistence and metabolism of fenthion in orange fruit were studied in field conditions. The fenthion was transformed to fenthion sulfoxide and fenthion sulfone. Sunlight photodegradation experiments showed that this transformation is due to the action of sunlight. Residues were found only in the fruit peel. Fenthion showed a rapid degradation rate with a half-life of ca. 6 days. Fenthion sulfoxide was degraded more slowly with a half-life of ca. 14 days and represented the major residue. Fenthion sulfone was present in low quantities.

Incidence of patulin in fruits and fruit juices marketed in Campinas, Brazil

One hundred and eleven samples of processed fruit juices (apple, grape, pineapple, papaya, guava, banana and mango) and 38 samples of sound fruits (apple, papaya, mango, pear and peach) produced and marketed in Brazil, were analysed for patulin by HPLC. Only one out of 30 samples of apple juice was found positive at 17 μg/l. Patulin was not detected in the other foodstuffs. It was found in 14 samples of spoiled fruit samples of apple (150-267 μg/kg), pear (134-245 μg/kg) and peach (92-174 μg/kg). Confirmation of the identity of patulin was based on the UV spectrum obtained by the HPLC diode array detector, compared with that of standard patulin, TLC developed by several solvent systems and sprayed with 3-methyl-2-benzothiazolinone hydrazone, and by acetylation with acetic anhydride.

Activity of benomyl for control of postbloom fruit drop of citrus caused by Colletotrichum acutatum

Postbloom fruit drop (PFD) of citrus caused by Colletotrichum acutatum produces orange-brown lesions on petals and induces the abscission of young fruitlets and the retention of the calyces. Despite the fact that C. acutatum is not highly sensitive to benomyl in culture, this fungicide provides good control of the disease under field conditions. This study was undertaken to determine the effect of benomyl on various stages of disease development to understand the basis for its effectiveness in the field. We found that benomyl at 1.0 μg/ml reduced colony area of C. acutatum by about 75% and completely inhibited growth of C. gloeosporioides. Benomyl did not prevent conidial germination even at 100 μg/ml, but reduced germ tube elongation at 10 and 100 μg/ml. When benomyl was applied to flower clusters on screen-house-grown plants before inoculation, disease severity was greatly reduced. Applications at 24 and 48 h, but not at 72 h, after inoculation reduced PFD severity. Application of benomyl to symptomatic petals not bearing conidia did not prevent or reduce production of inoculum. Application to petals bearing conidia reduced viability of these fungal propagules by only about 50%. The viability of appressoria on mature leaves was not affected by benomyl application. Even when appressoria on mature leaves were stimulated to germinate by treatment with flower extracts, subsequent application of benomyl did not reduce propagule numbers below original levels. Benomyl appears to act by preventing infection and early development of the fungus in petals. However, once symptoms have developed, this fungicide has only minimal effects on further disease development and spread.

Presence of Xylella fastidiosa in sweet orange fruit and seeds and its transmission to seedlings

Xylella fastidiosa, a xylem-limited bacterium, causes several economically important diseases in North, Central, and South America. These diseases are transmitted by sharpshooter insects, contaminated budwood, and natural root-grafts. X. fastidiosa extensively colonizes the xylem vessels of susceptible plants. Citrus fruit have a well-developed vascular system, which is continuous with the vascular system of the plant. Citrus seeds develop very prominent vascular bundles, which are attached through ovular and seed bundles to the xylem system of the fruit. Sweet orange (Citrus sinensis) fruit of cvs. Pera, Natal, and Valencia with characteristic symptoms of citrus variegated chlorosis disease were collected for analysis. X. fastidiosa was detected by polymerase chain reaction (PCR) in all main fruit vascular bundles, as well as in the seed and in dissected seed parts. No visual abnormalities were observed in seeds infected with the bacterium. However, the embryos of the infected seeds weighed 25% less than those of healthy seeds, and their germination rate was lower than uninfected seeds. There were about 2,500 cells of X. fastidiosa per infected seed of sweet orange, as quantified using real-time PCR techniques. The identification of X. fastidiosa in the infected seeds was confirmed by cloning and sequencing the specific amplification product, obtained by standard PCR with specific primers. X. fastidiosa was also detected in and recovered from seedlings by isolation in vitro. Our results show that X. fastidiosa can infect and colonize fruit tissues including the seed. We also have shown that X. fastidiosa can be transmitted from seeds to seedlings of sweet orange. To our knowledge, this is the first report of the presence of X. fastidiosa in seeds and its transmission to seedlings.

Genetic control of fruit-setting percentage of tomatoes tolerant to high temperatures

The aim of present work was to study, through means and variances of generations, the genetic control of fruit-set percentage in tomatoes, in a biparental cross between line Jab-95 (resistant to fruit-set) and 'Caribe' cultivar (susceptible to fruit-set) after being subjected to high temperatures. F1, F2, and backcross generations for both parents (P 1, P2) were produced in a greenhouse at FCAVUNESP, Jaboticabal-SP, Brazil. A randomized complete block experimental design with four replications was used to evaluate the different generations. Estimates of genetic parameters were obtained according to Mather and Jinks (1982). An additive-dominant model was fitted to explain the variation observed. The mean degree of dominance (0.54), indicated incomplete dominance in the direction of increasing fruit-set percentage at high temperatures. The genetic control of fruit-set percentage, at high temperatures, for tomato was found to be oligogenic or polygenic (3.54 genes). The heritability in a limited sense was 83.91%, suggesting that the selection of individuals based on the characteristic evaluated can be efficient.

Fruit and seed exploitation by small rodents of the Brazilian Atlantic forest

In the Brazilian Atlantic forest (BAF) there are at least 57 rodent species and most of them are considered omnivorous. These species feed, more or less frequently, on fruits and seeds. Nevertheless the potential role of each species as frugivorous, seed predator or seed disperser is still unclear. In the present study we analyzed patterns of fruit and seed exploitation by eight small rodent species from an Atlantic Forest site. We offered to captive animals fruits of 30 plant species (23 genera, 15 families). After 48 h we recorded consumption patterns of pulp/aril and seed. Rodent species differed in their patterns of fruit and seed exploitation. The smallest species, Akodon serrensis, Oligoryzomys nigripes, and Wilfredomys pictipes (body size range : 26-45 g), and also the medium-sized Oecomys aff. concolor (84 g) fed mainly on pulp and also on small to medium-sized seeds (< 10 mm diameter). The medium-sized rodent, Oryzomys russatus (91 g) fed on pulp and also on seeds with diameter ≤ 15 mm. Thus larger seeds remain intact after being manipulated by such species. The medium-sized Delomys dorsalis (72 g) and the larger Trinomys iheringi (274 g) and Nectomys squamipes (253 g) form a third group, which consumed both fruit and seed of most species independent of their size. These later two species and also O. russatus are probably the main seed predators in the rodent community of the BAF.

Postharvest conservation of 'Tommy Atkins' mango fruit influenced by gamma radiation, wax, hot water, and refrigeration

It was aimed to extend the postharvest conservation of 'Tommy Atkins' mango fruits harvested in break maturity stage. Fruits were submitted at the following treatments: hot water treatment (55°C for 5 minutes) and benomyl 1,000 mg.L-1; irradiation with 0,8 or 1,0 kGy; irradiation associated at carnaúba wax; and control. The fruits were stored at 10°C and 85 - 90%RH during 21 days, and then removed to ambient temperature (25,7±0,7°C and 87,1±2,2%RH). Through the storage time, the evolution of fresh weight, color, rottenness, total soluble solids (TSS), total titratable acidity (TTA), and TSS/TTA ratio were measured. 'Tommy Atkins' mango fruits can have shelf life notably increased, when they were submitted to hot water treatment (55°C for 5 minutes) or γ radiation (0,8 and 1,0 kGy), associated with carnaúba wax application, before cold storage. These treatments increased the fruit resistance at refrigerated storage, and improved shelflife after transferring to ambient temperature.

Potential of Brazilian eugenia myrtaceae - As ornamental and as a fruit crop

Brazilian Myrtaceae comprises several genera of trees and shrubs used for ornamental and fruit production. In addition to the well known Guava, Pitanga and Jaboticaba, other species could be used for fruitculture, due the value and quality of their fruits and adaptation to some climate conditions mainly the subtropical one. Nine species of Eugenia were evaluated at Jaboticabal, located at 48° W and 21° S in São Paulo state in a germplasm bank. The average rain by year is 1431 mm and the temperature 22,2° C at an altitude of 575 m. The species are Eugenia klozschiana Berg. (Pero-do-campo), E. stipitata Mc Vaugh (Araça-boi), E. tomentosa Camb. (Cabeludinha), E. dysentherica DC. (Cagaita), E. brasiliensis Berg. (Grumixama), E.pitanga (Pitanga-anã), E. luchsnathiana Berg. (Pitomba), E. uvalha Camb. (Uvaia) and E. involucrata DC. (Cereja-do-rio-grande). The evaluations comprised tree development, fruit quality and leaf and flower morphological studies. The main results are: the trees of Pera-do-campo and Pitanga-anã are small shrubs of 1 to 2 m height, Araça-boi and Cabeludinha are small trees, 3 to 5 m high, and the other species are tall trees, with 5 to 10 m height. The species adapted well to the subtropical conditions, except for Araça-boi, which is native to the Amazonian region and exhibited a severe fungus disease infection. In relation to fruit quality, all the species had edible fruit, some were sweet and juicy, Cabeludinha, Grumixama, Pitomba, Cereja-do-rio grande and Pitanga-anã, while others had high acidity (Araça-boi, Pera-do-campo, Cagaita and Uvaia and were more suitable for processing. Simple, single leaves were characteristic of all species, but with different sizes and shapes., With the addition of color, smell and other characteristics, leaf size and shape were useful for comparative classification. Flower components and structure are described also.