The Missing Part of Seed Dispersal Networks: Structure and Robustness of Bat-Fruit Interactions

Mutualistic networks are crucial to the maintenance of ecosystem services. Unfortunately, what we know about seed dispersal networks is based only on bird-fruit interactions. Therefore, we aimed at filling part of this gap by investigating bat-fruit networks. It is known from population studies that: (i) some bat species depend more on fruits than others, and (ii) that some specialized frugivorous bats prefer particular plant genera. We tested whether those preferences affected the structure and robustness of the whole network and the functional roles of species. Nine bat-fruit datasets from the literature were analyzed and all networks showed lower complementary specialization (H(2)' = 0.3760.10, mean 6 SD) and similar nestedness (NODF = 0.5660.12) than pollination networks. All networks were modular (M=0.32 +/- 0.07), and had on average four cohesive subgroups (modules) of tightly connected bats and plants. The composition of those modules followed the genus-genus associations observed at population level (Artibeus-Ficus, Carollia-Piper, and Sturnira-Solanum), although a few of those plant genera were dispersed also by other bats. Bat-fruit networks showed high robustness to simulated cumulative removals of both bats (R = 0.55 +/- 0.10) and plants (R = 0.68 +/- 0.09). Primary frugivores interacted with a larger proportion of the plants available and also occupied more central positions; furthermore, their extinction caused larger changes in network structure. We conclude that bat-fruit networks are highly cohesive and robust mutualistic systems, in which redundancy is high within modules, although modules are complementary to each other. Dietary specialization seems to be an important structuring factor that affects the topology, the guild structure and functional roles in bat-fruit networks.

The gene transformer-2 of Anastrepha fruit flies (Diptera, Tephritidae) and its evolution in insects

Background: In the tephritids Ceratitis, Bactrocera and Anastrepha, the gene transformer provides the memory device for sex determination via its auto-regulation; only in females is functional Tra protein produced. To date, the isolation and characterisation of the gene transformer-2 in the tephritids has only been undertaken in Ceratitis, and it has been shown that its function is required for the female-specific splicing of doublesex and transformer pre-mRNA. It therefore participates in transformer auto-regulatory function. In this work, the characterisation of this gene in eleven tephritid species belonging to the less extensively analysed genus Anastrepha was undertaken in order to throw light on the evolution of transformer-2. Results: The gene transformer-2 produces a protein of 249 amino acids in both sexes, which shows the features of the SR protein family. No significant partially spliced mRNA isoform specific to the male germ line was detected, unlike in Drosophila. It is transcribed in both sexes during development and in adult life, in both the soma and germ line. The injection of Anastrepha transformer-2 dsRNA into Anastrepha embryos caused a change in the splicing pattern of the endogenous transformer and doublesex pre-mRNA of XX females from the female to the male mode. Consequently, these XX females were transformed into pseudomales. The comparison of the eleven Anastrepha Transformer-2 proteins among themselves, and with the Transformer-2 proteins of other insects, suggests the existence of negative selection acting at the protein level to maintain Transformer-2 structural features. Conclusions: These results indicate that transformer-2 is required for sex determination in Anastrepha through its participation in the female-specific splicing of transformer and doublesex pre-mRNAs. It is therefore needed for the auto-regulation of the gene transformer. Thus, the transformer/transfomer-2 > doublesex elements at the bottom of the cascade, and their relationships, probably represent the ancestral state ( which still exists in the Tephritidae, Calliphoridae and Muscidae lineages) of the extant cascade found in the Drosophilidae lineage ( in which tra is just another component of the sex determination gene cascade regulated by Sex-lethal). In the phylogenetic lineage that gave rise to the drosophilids, evolution co-opted for Sex-lethal, modified it, and converted it into the key gene controlling sex determination.

A hybrid material assembled by anthocyanins from acai fruit intercalated between niobium lamellar oxide

Organic-inorganic hybrid materials can be prepared dispersing organic species into well-defined inorganic nanoblocks. This paper describes the immobilization of natural dyes from the extract of the Brazilian acai-fruit into two types of layered hexaniobate precursors derived from H(2)K(2)Nb(6)O(17): (i) colloidal dispersion of niobate exfoliated nanoparticles and (ii) niobate pre-intercalated with tetraethylammonium cations (TEA(+)). The restacking of exfoliated particles in the presence of acai anthocyanins promotes their intercalation and produces stacked layers showing large basal spacing (ca. 50 angstrom). The TEA(+) pre-intercalated niobate provides particles with lower content of dye species than the exfoliated precursor but with higher degree of organization and regularity according to X-ray diffraction data and images obtained by electron microscopies. Vibrational (FTIR and Raman) and (13)C NMR spectroscopies indicate the presence of flavylium cations in the hybrid materials and spectral profiles characteristic of glycosylated anthocyanidins. According to thermal analysis results, the purplish hybrids materials are more stable than the free acai-dyes. One hybrid sample was heated under air up to 170 degrees C and maintained at this temperature for 240 min. No weight loss events were observed and the sample retained its original color, indicating that the intercalation of anthocyanin into hexaniobate increases its thermal stability. Considering the structural, chemical, optical and thermal properties of the synthesized hybrid materials, they might be good candidates to be investigated for future specialized applications.

Response of oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), eggs to gamma radiation

As insects increase in radiotolerance as they develop and usually several developmental stages of the pest may be present in the fresh shipped commodity, it is important to know the radiation susceptibility of the stages of the target insect before the establishment of ionizing radiation quarantine treatments. This study was performed to determine the radiotolerance of eggs of the oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), to gamma radiation. This species is considered as one of the most serious worldwide pests for temperate fruits, especially peaches. Eggs (12 h old) were exposed to 0 (control), 25, 35, 50, 75, 100, 125 and 150 Gy of gamma radiation. Surviving larvae were allowed to feed on an artificial diet. Three days after irradiation, it was verified that larvae`s cephalic capsules were significantly affected by gamma radiation, and the estimated mean LD(90) and LD(99) were 66.3 Gy and 125.8 Gy, respectively. Oriental fruit moth eggs revealed to be quite radiosensitive and very low doses as 50 Gy were sufficient to disrupt G. molesta embryogenesis. At 25 Gy, only male adults originated from the surviving larvae and, after mating with untreated fertile females, shown to be sterile. (C) 2010 Elsevier Ltd. All rights reserved.

Characterization of different fruit wines made from cacao, cupuassu, gabiroba, jaboticaba and umbu

The main aim of this work was to produce fruit wines from pulp of gabiroba, cacao, umbu, cupuassu and jaboticaba and characterize them using gas chromatography-mass spectrometry for determination of minor compounds and gas chromatography-flame ionization detection for major compounds. Ninety-nine compounds (C(6) compounds, alcohols, monoterpenic alcohols, monoterpenic oxides, ethyl esters, acetates, volatile phenols, acids, carbonyl compounds, sulfur compounds and sugars) were identified in fruit wines. The typical composition for each fruit wine was evidenced by principal component analysis and Tukey test. The yeast UFLA CA 1162 was efficient in the fermentation of the fruit pulp used in this work. The identification and quantification of the compounds allowed a good characterization of the fruit wines. With our results, we conclude that the use of tropical fruits in the production of fruit wines is a viable alternative that allows the use of harvest surpluses and other underused fruits, resulting in the introduction of new products into the market. (C) 2010 Elsevier Ltd. All rights reserved.

Ethanol production process from banana fruit and its lignocellulosic residues: Energy analysis

Tropical countries, such as Brazil and Colombia, have the possibility of using agricultural lands for growing biomass to produce bio-fuels such as biodiesel and ethanol. This study applies an energy analysis to the production process of anhydrous ethanol obtained from the hydrolysis of starch and cellulosic and hemicellulosic material present in the banana fruit and its residual biomass. Four different production routes were analyzed: acid hydrolysis of amylaceous material (banana pulp and banana fruit) and enzymatic hydrolysis of lignocellulosic material (flower stalk and banana skin). The analysis considered banana plant cultivation, feedstock transport, hydrolysis, fermentation, distillation, dehydration, residue treatment and utility plant. The best indexes were obtained for amylaceous material for which mass performance varied from 346.5 L/t to 388.7 L/t, Net Energy Value (NEV) ranged from 9.86 MJ/L to 9.94 MJ/L and the energy ratio was 1.9 MJ/MJ. For lignocellulosic materials, the figures were less favorable: mass performance varied from 86.1 to 123.5 L/t, NEV from 5.24 10 8.79 MJ/L and energy ratio from 1.3 to 1.6 MJ/MJ. The analysis showed, however, that both processes can be considered energetically feasible. (C) 2010 Elsevier Ltd. All rights reserved.

Energy and exergy analysis of ethanol production process from banana fruit

An alternative for ethanol production, is the use of vegetable waste, such as excess of banana production, that are evaluated in 2,400,000 t/year, which includes: residual banana fruit and lignocellulosic material. This paper analyzes the energetic and exergetic behavior to carry the process developed at laboratory scale to a plant processing of banana for the ethanol production, involving: growing and transport of the vegetable material, hydrolysis of banana fruit, sugar fermentation, ethanol distillation and utility plant. Finally, energy and exergy indicators are obtained. The results show a positive energy balance when banana fruit is used for ethanol production, but some process modification must be done looking for improving the exergetic efficiency in ethanol production.

Inhibition of Auxin Transport from the Ovary or from the Apical Shoot Induces Parthenocarpic Fruit-Set in Tomato Mediated by Gibberellins

Fruit-set in tomato (Solanum lycopersicum) depends on gibberellins and auxins (GAs). Here, we show, using the cv MicroTom, that application of N-1-naphthylphthalamic acid (NPA; an inhibitor of auxin transport) to unpollinated ovaries induced parthenocarpic fruit-set, associated with an increase of indole-3-acetic acid (IAA) content, and that this effect was negated by paclobutrazol (an inhibitor of GA biosynthesis). NPA-induced ovaries contained higher content of GA(1) (an active GA) and transcripts of GA biosynthetic genes (SlCPS, SlGA20ox1, and -2). Interestingly, application of NPA to pollinated ovaries prevented their growth, potentially due to supraoptimal IAA accumulation. Plant decapitation and inhibition of auxin transport by NPA from the apical shoot also induced parthenocarpic fruit growth of unpollinated ovaries. Application of IAA to the severed stump negated the plant decapitation effect, indicating that the apical shoot prevents unpollinated ovary growth through IAA transport. Parthenocarpic fruit growth induced by plant decapitation was associated with high levels of GA(1) and was counteracted by paclobutrazol treatment. Plant decapitation also produced changes in transcript levels of genes encoding enzymes of GA biosynthesis (SlCPS and SlGA20ox1) in the ovary, quite similar to those found in NPA-induced fruits. All these results suggest that auxin can have opposing effects on fruit-set, either inducing (when accumulated in the ovary) or repressing (when transported from the apical shoot) that process, and that GAs act as mediators in both cases. The effect of NPA application and decapitation on fruit-set induction was also observed in MicroTom lines bearing introgressed DWARF and SELF-PRUNING wild-type alleles.

Fruit flies (Diptera, Tephritidae) and their associations with native host plants in a remnant area of the highly endangered Atlantic Rain Forest in the State of Espirito Santo, Brazil

The results presented in this paper refer to a host survey, lasting approximately three and a half years (February 2003-july 2006), undertaken in the Vale do Rio Doce Natural Reserve, a remnant area of the highly endangered Atlantic Rain Forest located in Linhares County, State of Espirito Santo, Brazil. A total of 330 fruit samples were collected from native plants, representing 248 species and 51 plant families. Myrtaceae was the most diverse family with 54 sampled species. Twenty-eight plant species, from ten families, are hosts of ten Anastrepha species and of Ceratitis capitata (Wiedemann). Among 33 associations between host plants and fruit flies, 20 constitute new records, including the records of host plants for A. fumipennis Lima and A. nascimentoi Zucchi. The findings were discussed in the light of their implications for rain forest conservation efforts and the study of evolutionary relationships between fruit flies and their hosts.

Isolation and characterization of microsatellite loci in Colletotrichum acutatum, the causal agent of postbloom fruit drop on citrus

From a genomic enriched library, we developed 27 primer pairs from microsatellite flanking sequences for Colletotrichum acutatum, associated to postbloom fruit drop disease on citrus. Loci were characterized using 40 monosporic C. acutatum isolates. Nine primer pairs successfully amplified polymorphic microsatellite regions, with 3-6 alleles per locus, and mean heterozygosities ranging 0.093-0.590 across loci. The suitability of these primers was investigated in four Colletotrichum species as well. These microsatellite markers will be useful for genetic analyses and epidemiological studies of C. acutatum.

Prepenetration Stages of Guignardia psidii in Guava: Effects of Temperature, Wetness Duration and Fruit Age

This study examined the effects of temperature and wetness duration in vitro and in vivo as well as the effects of fruit age on germination and appressoria formation by conidia of Guignardia psidii, the causal agent of black spot disease in guava fruit. The temperatures tested for in vitro and in vivo experiments were 10, 15, 20, 25, 30, 35 and 40 degrees C. The wetness periods studied were 6, 12, 24, 36 and 48 h in vitro and 6, 12 and 24 h in vivo. Fruit 10, 35, 60, 85 and 110-days old were inoculated and maintained at 25 degrees C, with a wetness period of 24 h. Temperature and wetness duration affected the variables evaluated in vitro and in vivo. All variables reached their maximum values at between 25 and 30 degrees C with a wetness duration of 24 h in vivo and 48 h in vitro. These conditions resulted in 31.3% conidia germination, 33.6% appressoria formation and 32.5% appressoria melanization in vitro, and 50.4% conidia germination and 9.5% appressoria formation in vivo. Fruit age also influenced these factors. As fruit age increased, conidia germination and appressoria formation gradually increased. Conidia germination and appressoria formation were 10.8% and 2.3%, respectively, in 10-day-old fruits. In 110-day-old fruits, conidia germination and appressoria formation were 42.5% and 23.2% respectively.

Colletotrichum gloeosporioides, a new causal agent of citrus post-bloom fruit drop

Citrus post-bloom fruit drop (caused by Colletotrichum acutatum) frequently occurs in the southwestern region of So Paulo State, Brazil. A survey of Colletotrichum isolates associated with symptoms of post-bloom fruit drop in So Paulo State showed C. gloeosporioides in addition to C. acutatum. The objectives of this study were to confirm the identification of C. gloeosporioides isolated from symptomatic citrus flowers, to test the pathogenicity of C. gloeosporioides isolates, to compare the development of disease caused by C. gloeosporioides and C. acutatum, and to determine the frequency of C. gloeosporioides in a sample of isolates obtained from symptomatic flowers in different regions of So Paulo State. Through the use of species-specific primers by PCR, 17.3% of 139 isolates were C. gloeosporioides, and the remaining 82.7% were C. acutatum. The pathogenicity tests, carried out in 3-year old potted plants of sweet oranges indicated that both species caused typical symptoms of the disease including blossom blight and persistent calyces. Incubation periods (3.5 and 3.9 days, respectively, for C. acutatum and C. gloeosporioides) and fruit sets (6.7 and 8.5%, respectively for C. acutatum and C. gloeosporioides) were similar for both species. The incidences of blossom blight and persistent calyces were higher on plants inoculated with C. acutatum than in those inoculated with C. gloeosporioides. Conidial germination was similar for both species under different temperatures and wetness periods. Under optimal conditions, appressorium formation and melanisation were higher for C. gloeosporioides than for C. acutatum. These results indicated that Colletotrichum gloeosporioides is a new causal agent of post-bloom fruit drop.

Molecular evidence of phytoplasma associated with witches` broom on passion fruit in five Brazilian States

Phytoplasmas are cell wall-less prokaryotes and phloem-inhabitants associated with diseases that affect several crops. Passion fruit is a tropical plant species cultivated in various Brazilian regions. Diseases are among the factors that may cause damage to this crop, and witches` broom is a very important one. This disease, associated with a phytoplasma, has been reported only in Brazil, where it was described in Rio de Janeiro and Pernambuco States at the beginning of the 1980`s. In 2005-2006, symptomatic plants Suspected of phytoplasma infection were sampled in areas located in Sao Paulo, Parana, Rio de Janeiro, Sergipe and Bahia. Amplification of DNA fragments of 1.2kb from nested PCR primed by the pairs 16mF2/mR1 and 16F2n/R2 revealed the presence of phytoplasma in the tissue of plants from all sampled regions. Molecular detection of the agent allowed confirmation of the diagnosis based on the symptomatology; demonstrated the strong association between diseased plants and a phytoplasma, confirming previous investigations based on electron microscopy;, and revealed the present occurrence of the agent in the States of Bahia, Parana, Rio de Janeiro, Sergipe, and Sao Paulo.

Peach brown rot incidence related to pathogen infection at different stages of fruit development in an organic peach production system

Brown rot, caused by Monilinia fructicola, is the most widespread disease for organic peach production systems in Brazil. The objective of this study was to determine the favorable periods for latent infection by M. fructicola in organic systems. The field experiment was carried out during 2006, 2007 and 2008 using the cultivar Aurora. After thinning fruits were bagged using white paraffin bags, and the treatments were performed by removing the bags and exposing the fruit for four days to the natural infection during each of seven fruit stages from pit hardening to harvest. Throughout the entire growing season, the conidial density and the weather variables were measured and related to the disease incidence using multiple regression analyses. At the fourth day after harvest in each season, the cumulative disease incidence was assessed, and it ranged from 40 to 98%. The incidence of brown rot on fruit that were exposed during the embryo growing stage was lower than that of unbagged fruit throughout the entire season in 2006 and 2008. The relative humidity and the conidia density were significantly correlated to disease incidence. Based on our results, M. fructicola can infect peaches during any stage of fruit development, and control of the disease must be revised to account for organic peach production systems. (C) 2011 Elsevier Ltd. All rights reserved.

An integrated molecular map of yellow passion fruit based on simultaneous maximum-likelihood estimation of linkage and linkage phases

The development of genetic maps for auto-incompatible species, such as the yellow passion fruit (Passiflora edulis Sims f.flavicarpa Deg.) is restricted due to the unfeasibility of obtaining traditional mapping populations based on inbred lines. For this reason, yellow passion fruit linkage maps were generally constructed using a strategy known as two-way pseudo-testeross, based on monoparental dominant markers segregating in a 1:1 fashion. Due to the lack of information from these markers in one of the parents, two individual (parental) maps were obtained. However, integration of these maps is essential, and biparental markers can be used for such an operation. The objective of our study was to construct an integrated molecular map for a full-sib population of yellow passion fruit combining different loci configuration generated from amplified fragment length polymorphisms (AFLPs) and microsatellite markers and using a novel approach based on simultaneous maximum-likelihood estimation of linkage and linkage phases, specially designed for outcrossing species. Of the total number of loci, approximate to 76%, 21%, 0.7%, and 2.3% did segregate in 1:1, 3:1, 1:2:1, and 1:1:1:1 ratios, respectively. Ten linkage groups (LGs) were established with a logarithm of the odds (LOD) score >= 5.0 assuming a recombination fraction : <= 0.35. On average, 24 markers were assigned per LG, representing a total map length of 1687 cM, with a marker density of 6.9 cM. No markers were placed as accessories on the map as was done with previously constructed individual maps.