978 resultados para tropical fruit species
Resumo:
• We developed the first microsatellites for Passiflora setacea and characterized new sets of markers for P. edulis and P. cincinnata, enabling further genetic diversity studies to support the conservation and breeding of passion fruit species. • We developed 69 microsatellite markers and, in conjunction with assessments of cross-amplification using primers available from the literature, present 43 new polymorphic microsatellite loci for three species of Passiflora. The mean number of alleles per locus was 3.1, and the mean values of the expected and observed levels of heterozygosity were 0.406 and 0.322, respectively. • These microsatellite markers will be valuable tools for investigating the genetic diversity and population structure of wild and commercial species of passion fruit (Passiflora spp.) and may be useful for developing conservation and improvement strategies by contributing to the understanding of the mating system and hybridization within the genus.
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Many tropical tree species produce growth rings in response to seasonal environmental factors that influence the activity of the vascular cambium. We applied the following methods to analyze the annual nature of treering formation of 24 tree species from a seasonal semi-deciduous forest of southeast Brazil: describing wood anatomy and phenology, counting tree rings after cambium markings, and using permanent dendrometer bands. After 7 years of systematic observations and measurements, we found the following: the trees lost their leaves during the dry season and grew new leaves at the end of the same season; trunk increment dynamics corresponded to seasonal changes in precipitation, with higher increment (active period) during the rainy season (October-April) and lower increment (dormant period) during the dry season (May-September); the number of tree rings formed after injuries to the cambium coincided with the number of years since the extraction of the wood samples. As a result of these observations, it was concluded that most study trees formed one growth ring per year. This suggests that tree species from the seasonal semi-deciduous forests of Brazil have an annual cycle of wood formation. Therefore, these trees have potential for use in future studies of tree age and radial growth rates, as well as to infer ecological and regional climatic conditions. These future studies can provide important information for the management and conservation of these endangered forests.
Resumo:
Samples of fruit from the jussara palm plant (Euterpe edulis), collected in different regions of the state of Santa Catarina. Brazil, were analyzed for chemical composition. phenolic acids. anthocyanins, flavonoids and fatty acids profile. Results indicated that the jussara fruit has a high lipid content (18.45-44.08%), oleic acid (44.17-55.61%) and linoleic acid (18.19-25.36%) are the fatty acids found in the highest proportion, and other components were proteins (5.13-8.21%). ash (1.55-3.32%) and moisture (34.95-42.47%). Significant differences were found in the total phenolic, total monomeric anthocyanins and other flavonoids for the samples from the five cultivation regions. The fruit from region E harvested in summer, with high temperatures and medium altitudes, had the highest contents of total phenolics (2610.86 +/- 3.89 mg 100 g(-1) GAE) and monomeric anthocyanins (1080.54 +/- 2.33 mg 100g(-1) cy-3-glu). The phenolic compound included ferulic, gallic, hydroxybenzoic and p-coumaric acids, as well as catechin, epicatechin and quercetin. The results show promising perspectives for the exploitation of this tropical fruit with a chemical composition comprising considerable phenolic acids and flavonoids compounds and showing activity antioxidant. (C) 2010 Published by Elsevier Ltd.
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This paper investigates factors influencing the public’s support for conservation of tropical reptile species in a focal group drawing on Australian data and an experiment involving a sample of the Australian public. The influences of the likeability of the species, their degree of endangerment, ethical considerations as well as knowledge are examined and found to be important. Likeability is found to be much less important than the existing literature suggests. This is highlighted by comparing the likeability of the focal group of reptiles with that for a group of birds and a group of mammals with differences in willingness to pay for their conservation.
Resumo:
The potential for the ethylene binding inhibitor, 1-methylcyclopropene, to delay ripening of 'Hass' avocado, 'African Pride' custard apple, 'Kensington Pride' mango and 'Solo' papaya was examined. Fruit were gassed with 25 muL/L 1-methylcyclopropene for 14 h at 20 degreesC, followed by treatment with 100 muL/L ethylene for 24 h, and then ripened at 20 degreesC. Ethylene treatment alone generally halved the number of days for fruit to reach the ripe stage, compared with untreated fruit. 1-Methylcyclopropene treatment alone increased the number of days to ripening by 4.4 days (40% increase), 3.4 days (58%), 5.1 days (37%) and 15.6 days (325%) for avocado, custard apple, mango and papaya, respectively, compared with untreated fruit. Applying 1-methylcyclopropene to the fruit before ethylene prevented the accelerated ripening normally associated with ethylene treatment, so that the number of days to ripening for fruit treated with 1-methylcyclopropene plus ethylene was similar to the number of days to ripening for fruit treated with 1-methylcyclopropene alone. 1-Methylcyclopropene treatment was associated with slightly higher severity of external blemishes in papaya and custard apple, slightly higher rots severity in avocado, custard apple and papaya, and at least double the severity of stem rots in mango, relative to fruit not treated with 1-methylcyclopropene. Thus, 1-methylcyclopropene treatment has the potential to reduce the risk of premature ripening of avocado, custard apple, mango and papaya fruit due to accidental exposure to ethylene. However, additional precautions may be necessary to reduce disease severity associated with 1-methylcyclopropene treatment.
Resumo:
This study investigated treatment of mango (Mangifera indica L.) fruit with 2 host defence-promoting compounds for suppression of anthracnose disease (Colletotrichum gloeosporioides). Cultivar 'Kensington Pride' fruit were treated at concentrations of up to 1000 mg/L with either potassium phosphonate or salicylic acid. Applications were by various combinations of pre- and postharvest dips and vacuum infiltration. Postharvest treatments at up to 2000 mg/L salicylic acid were evaluated in a second fruiting season. Fruit were either uninoculated or inoculated with the fungal pathogen. Colour, firmness and disease-severity were assessed during shelf life at 23 degreesC. There were no significant (P>0.05) effects of potassium phosphonate or salicylic acid on anthracnose disease severity in the first season. Moreover, phosphonate or salicylic acid treatment did not significantly affect fruit colour or firmness changes. There were significant (P
Resumo:
The effects of conditioning and hot water treatments on immature and mature 'Kensington' mangoes were examined. A hot water treatment of 47 degreesC fruit core temperature held for 15 min increased weight loss (50%), fruit softness (15%), disrupted starch hydrolysis and interacted with maturity to reduce the skin yellowness (40-51%) of early harvested fruit. Immature fruit were more susceptible to hot water treatment-induced skin scalding, starch layer and starch spot injuries and disease. Conditioning fruit at 40 degreesC for up to 16 h before hot water treatment accelerated fruit ripening, as reflected in higher total soluble solids and lower titratable acidity levels. As fruit maturity increased, the tolerance to hot water treatment-induced skin scalding and the retention of starch layers and starch spots increased and susceptibility to lenticel spotting decreased. A conditioning treatment of either 22 degrees or 40 degreesC before hot water treatment could prevent the appearance of cavities at all maturity levels. The 40 degreesC conditioning temperature was found to be more effective in increasing fruit heat tolerance than the 22 degreesC treatment; the longer the time of conditioning at 40 degreesC, the more effective the treatment (16 v. 4 h). For maximum fruit quality, particularly for export markets, it is recommended that mature fruit are selected and conditioned before hot water treatment to reduce the risk of heat damage.
Resumo:
To investigate the variation in quality of 'Hass' avocado fruit within an orchard, fruit were harvested at commercial maturity from 15 'Hass' trees of similar appearance, growing in three adjacent rows on the same soil type, and receiving similar management. Fruit were harvested at commercial maturity, and either ripened at 22 degreesC or stored at 2 or 7 degreesC for 3 or 5 weeks and then ripened. Significant positive correlations (based, on the mean for each datum tree) were noted between fruit flesh calcium (Ca) and magnesium (Mg) concentrations and the (Ca + Mg)/potassium ratio, and the number of days for the fruit to reach the eating ripe stage (DTR). Negative correlations were also observed between these minerals and anthracnose and mesocarp discolouration (MD) severity. Negative correlations were observed between fruit potassium (K) and phosphorus (P) concentrations and DTR. Fruit from trees with high fruit yield were generally smaller, with lower anthracnose and MD severity, ripened more slowly, and had higher flesh Ca concentrations. It is likely that cultural practices that maintain moderate to high fruit yield and reduce variation in yield will improve avocado fruit quality and reduce variability in quality. Since the main differences between adjacent trees in this trial were the seedling rootstocks of unknown origin, it is suggested that rootstocks can have a significant impact on avocado yield and fruit quality. (C) 2002 Elsevier Science B.V. All rights reserved.
Resumo:
Changes in carbohydrate metabolism of 'Kensington' mango fruit from 2 major production regions in Queensland were measured after conditioning fruit with hot air at 40degreesC for 0, 2, 4, 8 and 16 h or at 22degreesC for 16 h (control) followed by hot-water treatment at either 45degreesC fruit-core temperature for 30 min or 47degreesC fruit-core temperature held for 15 min. Advancing physiological maturity of 'Kensington' mango fruit was correlated with increased starch concentration within the mesocarp. An alpha-amylase inhibitor was present in unripe 'Kensington' mesocarp. alpha-Amylase activity was promoted by conditioning fruit at 40degreesC for 8 h, and this enhanced enzyme activity persisted until the fruit were ripe. Consequently, starch degradation was accelerated and the concentration of total soluble solids was higher in fruit conditioned at 40degreesC for 8 h than in fruit left at the lower temperature of 22degreesC for 16 h or not conditioned. Immediately on removal of fruit from hot-water treatment, activities of alpha-amylase and phosphorylase were inhibited. This inhibition was correlated with higher starch concentration and starch layer and starch spot injuries in these fruit. A positive correlation was also found between increased sucrose concentration and greater starch loss in 40degreesC conditioned 'Kensington' fruit. It is proposed that increased sugar concentration in the mesocarp increased the level of fruit heat tolerance.
Resumo:
To determine the potential for rootstocks to improve avocado quality, 'Hass' fruit from trees on seedling 'Velvick' (SV), clonal 'Velvick' (CV) or clonal 'Duke 7' (CD) rootstocks were harvested in 1999 and 2000, ripened at 20 C immediately after harvest (non-stored) or stored at 5 C for four weeks (stored), and then fruit quality and mineral concentrations determined. In 2000, non-stored CV fruit had lower severity of body rots (5% of flesh volume affected, caused mainly by Colletotrichum gloeosporioides) than CD fruit (20%), while body rots severity in stored CV fruit was 20% compared with 38% in stored CD fruit. Stored CV fruit had less severe diffuse discoloration (3% and 9% in 1999 and 2000, respectively) than CD fruit (7% and 20%, respectively). Stored CV fruit also had less severe vascular browning (19%) than CD fruit (33%) in 2000. In both seasons, CV fruit had 15-19% higher flesh calcium concentrations, 17-22% higher flesh boron concentrations, and 14-15% lower flesh nitrogen concentrations than CD fruit. In 2000, CV fruit also had 27% more skin calcium and 14% less skin nitrogen than CD fruit. There were no effects of rootstock on yield, canopy volume, measured length of non-suberized roots, average fruit weight, fruit length: width ratio, skin thickness, dry matter, proportion of the fruit skin purple-black when ripe, or seed mass: fruit weight ratio. These results suggest that there is potential to improve 'Hass' avocado quality through rootstock selection, and that tree and fruit mineral concentrations have a role in this relationship.
Resumo:
Eight tropical fruit pulps from Brazil were simultaneously characterised in terms of their antioxidant and antimicrobial properties. Antioxidant activity was screened by DPPH radical scavenging activity (126–3987 mg TE/100 g DW) and ferric reduction activity power (368–20819 mg AAE/100 g DW), and complemented with total phenolic content (329–12466 mg GAE/100 g DW) and total flavonoid content measurements (46–672 mg EE /100 g DW), whereas antimicrobial activity was tested against the most frequently found food pathogens. Acerola and açaí presented the highest values for the antioxidant-related measurements. Direct correlations between these measurements could be observed for some of the fruits. Tamarind exhibited the broadest antimicrobial potential, having revealed growth inhibition of Pseudomonas aeruginosa. Escherichia coli, Listeria monocytogenes, Salmonella sp. and Staphylococcus aureus. Açaí and tamarind extracts presented an inverse relationship between antibacterial and antioxidant activities, and therefore, the antibacterial activity cannot be attributed (only) to phenolic compounds.
Resumo:
The aim of this study was to test the hypothesis that the monodominant non-pioneer Peltogyne gracilipes, typically does not suffer density-dependent herbivory (Janzen-Connell model). Two components of intraspecific variation in leaf herbivory were measured: 1) the variation between individuals in the population at the same time and 2) the temporal variation in rates of damage to each individual. The study was carried out on Maracá Island, Roraima, Brazil in three plots (50 m χ 50 m) in each of three forest types: Peltogyne-rich forest (PRF), Peltogyne-poor forest (PPF), and forest without Peltogyne (FWP). Two other non-pioneer species (Ecclinusa guianensis and Pradosia surinamensis) were chosen for comparison because they were fairly abundant and their seedlings could be readily identified. The values of leaf area removed by herbivores of trees and seedlings of the three study species were in the range reported for other tropical tree species (2-16%, standing damage). There were no differences within species between forests. However, there was a significant difference among species but this was not correlated with seedling density. Peltogyne seedlings showed no evidence of density-dependent herbivory as predicted by the Janzen-Connell model despite the fact that adult trees were observed to suffer a mass defoliation in April 1992. This result suggests that Peltogyne may be dominant partly due to escape from herbivory in the early stages of its life although it may suffer occasional mass defoliation as an adult.