The abundance and diversity of fruit flies and their parasitoids change with elevation in guava orchards in a tropical Andean forest of Peru, independent of seasonality.

Lower elevations are generally thought to contain a greater abundance and diversity of insect communities and their natural enemies than higher elevations. It is less clear, however, how changes in seasons influence this pattern. We conducted a 2-year study (2013‒2014) in guava orchards located in a tropical Andean forest of Peru to investigate differences in fruit flies (Diptera: Tephritidae) and their parasitoid communities at two elevations and over two seasons. Fruit fly traps were installed, monitored, and guava fruits were sampled from eight orchards at low (800-950 m above sea level) and high (1,700-1,900 m above sea level) elevations and during the dry and rainy seasons. At each orchard, adult fruit fly trap captures and emergence of fruit flies and their parasitoids from guava fruit were quantified to determine their abundance and species composition. There was a greater abundance and species richness of fruit flies captured in traps at lower elevations, as well as higher abundance and species evenness of fruit flies that emerged from fruit, indicating that lower elevations are associated with larger fruit fly populations. The abundance, species richness and diversity of parasitoids were also greater at lower elevations. Consequently, guava fruit infestation and fruit fly parasitism rates were also greater at lower elevations. Seasonality also influenced fruit fly populations with a greater number of flies emerging from guava fruit and more fruit infested in the rainy season. However, seasonality had no effect on parasitoid population parameters or rate of parasitism, nor did it interact with elevation as an influence of populations of fruit flies or their parasitoids in guava orchards. This study highlights the importance of examining both elevation and seasonality for a better understanding of the population dynamics of fruit flies and their parasitoids in tropical agroecosystems.

Management alternatives for Carmenta theobromae (Busck, 1910) (Lepidoptera: Sesiidae) and Simplicivalva ampliophilobia (Lepidoptera: Cossidae), limiting pests of guava in Colombia.

The larval stages of Carmenta theobromae Busck (1910) and Simplicivalva ampliophilobia Davis, Gentili-Poole and Mitter (2008) attack the subcortical zone and pith in guava trees, respectively, in the first productive nucleus of fruit trees in Colombia: Hoya del Río Suárez (HRS). The presence of pest insects has been reported in 98% of the farms sampled in HRS (n = 124), with up to 96 and 11 simultaneous larvae per tree, respectively. Although the aspects of the basic biology and life cycle of both pests have been resolved, there are no strategies for managing populations in the field. Therefore, the aim of this study was to evaluate different management alternatives under laboratory and field conditions in HRS. In laboratory conditions, a completely randomized design was used in two separate experiments, each with six treatments: T1: Spinosad (a mixture of Spinosad A and D); T2: S-1,2-di(ethoxycarbonyl) ethyl 0,0-dimethylphosphorodithioate (chemical control); T3: Lecanicillium lecanii; T4: Beauveria bassiana; T5: Mix of B. bassiana and B. brongniartii, and T6: distilled water (control). The number of dead larvae per replicate per treatment was evaluated (DL), with experimental units of five and three larvae, respectively. In the field, to the two best alternatives found for each pest in the laboratory, pruning and keeping the area around the plants free of weeds were added as cultural management, in two separate additional experiments, each with three larvae as experimental unit per treatment. For C. theobromae, the best laboratory alternatives were chemical control (DL: 3.78) and L. lecanii (DL: 2.33), followed without statistical differences by B. bassiana (DL: 1.67). In the field, the virulence of B. bassiana improved (DL: 3), and together with pruning and keeping the area around the plants clear of weeds (DL: 3), they stood out as the best alternatives. For S. ampliophilobia under laboratory conditions, the best alternatives were Spinosad (2.74) and chemical control (DL: 2.66), without significant difference. In the field, there were no statistical differences between the alternatives, except for the control. This statistical parity of cultural practices, and biological and chemical management is an argument in favor of the use of the former to the detriment of the third, especially when the harmful effects of the molecule S-1,2 di (ethoxycarbonyl) ethyl 0, 0-dimethyl phosphorodithioate have been proven in air, water and agricultural soils, in addition to its association with thyroid cancer in humans. This is a strong argument to favor the use of synergies of cultural and biological management methods framed in IPM, as opposed to the use of chemical agents whose harmful effects are strongly documented, and whose use is becoming increasingly prohibited.

RNA-sequencing based gene expression landscape of guava cv. Allahabad Safeda and comparative analysis to colored cultivars.

BACKGROUND: Guava (Psidium guajava L.) is an important fruit crop of tropical and subtropical areas of the world. Genomics resources in guava are scanty. RNA-Seq based tissue specific expressed genomic information, de novo transcriptome assembly, functional annotation and differential expression among contrasting genotypes has a potential to set the stage for the functional genomics for traits of commerce like colored flesh and apple color peel. RESULTS: Development of fruit from flower involves orchestration of myriad molecular switches. We did comparative transcriptome sequencing on leaf, flower and fruit tissues of cv. Allahabad Safeda to understand important genes and pathways controlling fruit development. Tissue specific RNA sequencing and de novo transcriptome assembly using Trinity pipeline provided us the first reference transcriptome for guava consisting of 84,206 genes comprising 279,792 total transcripts with a N50 of 3603 bp. Blast2GO assigned annotation to 116,629 transcripts and PFam based HMM profile annotated 140,061 transcripts with protein domains. Differential expression with EdgeR identified 3033 genes in Allahabad Safeda tissues. Mapping the differentially expressed transcripts over molecular pathways indicate significant Ethylene and Abscisic acid hormonal changes and secondary metabolites, carbohydrate metabolism and fruit softening related gene transcripts during fruit development, maturation and ripening. Differential expression analysis among colored tissue comparisons in 3 cultivars Allahabad Safeda, Punjab Pink and Apple Color identified 68 candidate genes that might be controlling color development in guava fruit. Comparisons of red vs green peel in Apple Color, white pulp vs red pulp in Punjab Pink and fruit maturation vs ripening in non-colored Allahabad Safeda indicates up-regulation of ethylene biosynthesis accompanied to secondary metabolism like phenylpropanoid and monolignol pathways. CONCLUSIONS: Benchmarking Universal Single-Copy Orthologs analysis of de novo transcriptome of guava with eudicots identified 93.7% complete BUSCO genes. In silico differential gene expression among tissue types of Allahabad Safeda and validation of candidate genes with qRT-PCR in contrasting color genotypes promises the utility of this first guava transcriptome for its potential of tapping the genetic elements from germplasm collections for enhancing fruit traits.

First record of in vitro formation of ectomycorrhizae in Psidium cattleianum Sabine, a native Myrtaceae of the Brazilian Atlantic Forest.

Like many other species of trees native to the Brazilian Mata Atlântica (Atlantic Forest), the Myrtaceae, such as the Red Araza (Psidium cattleianum Sabine), are widely cited as arbuscular mycorrhizal formers. Nevertheless, recent studies show evidence that Myrtaceae from different tropical, subtropical and neotropical ecosystems can also prompt the formation of ectomycorrhizae, indicating that this species' ectomycorrhizal status should be further explored. Because of this, this research effort studied the in vitro interaction between the Red Araza and two ectomycorrhizal fungi isolates, belonging to the Pisolithus microcarpus (D17) and Scleroderma citrinum (UFSC-Sc133) species. An analysis was performed to determine the formation of ectomycorrhizal structures, or lack thereof, and the developmental differences between the in vitro mycorrhized and non-mycorrhized plants. The analysis proved that indeed an ectomycorrhizal association was developed between the Red Araza, and the D17 and UFSC-Sc133 isolates, a fact never before registered in the existing literature. After an in vitro period of 110 days, it was confirmed that the D17 and UFSC-Sc133 isolates formed mycorrhizal colonization of 91.6% and 15.7%, respectively. Furthermore, both isolates also promoted root thickening, and the formation of a fungal mantle and a Hartig net. However, when compared to the Control plants, the fungal isolates did not contribute to an increase in the development of the subject plants, possibly due to the specific experimental conditions used, such as a high humidity environment and high availability of nutrients in the symbiotic substrate.

Carotenoid Profile, Antioxidant Capacity, and Chromoplasts of Pink Guava (Psidium guajava L. Cv. 'Criolla') during Fruit Ripening.

Pigments of pericarp and pulp of pink guava (Psidium guajava L. cv. 'Criolla') were investigated to elucidate the profile and the accumulation of main carotenoids during four stages of fruit ripening by using HPLC-DAD and APCI-MS/MS analysis. Seventeen carotenoids were identified, and changes in their profile during fruit ripening were observed. The carotenoids all-trans-ß-carotene, 15-cis-lycopene, and all-trans-lycopene were present in all ripening stages, but all-trans-lycopene was found to be predominant (from 63% to 92% of total carotenoids) and responsible for the high lipophilic antioxidant capacity determined by spectrophotometric assays. By using light and transmission electron microscopy, the development of chromoplasts in pericarp and pulp was demonstrated. The accumulation of all-trans-lycopene and all-trans-ß-carotene coincided with the development of large crystals; the chromoplasts of pink guava belong, therefore, to the crystalline type.

Global Potential Distribution of Bactrocera carambolae and the Risks for Fruit Production in Brazil.

The carambola fruit fly, Bactrocera carambolae, is a tephritid native to Asia that has invaded South America through small-scale trade of fruits from Indonesia. The economic losses associated with biological invasions of other fruit flies around the world and the polyphagous behaviour of B. carambolae have prompted much concern among government agencies and farmers with the potential spread of this pest. Here, ecological niche models were employed to identify suitable environments available to B. carambolae in a global scale and assess the extent of the fruit acreage that may be at risk of attack in Brazil. Overall, 30 MaxEnt models built with different combinations of environmental predictors and settings were evaluated for predicting the potential distribution of the carambola fruit fly. The best model was selected based on threshold-independent and threshold-dependent metrics. Climatically suitable areas were identified in tropical and subtropical regions of Central and South America, Sub-Saharan Africa, west and east coast of India and northern Australia. The suitability map of B. carambola was intersected against maps of fruit acreage in Brazil. The acreage under potential risk of attack varied widely among fruit species, which is expected because the production areas are concentrated in different regions of the country. The production of cashew is the one that is at higher risk, with almost 90% of its acreage within the suitable range of B. carambolae, followed by papaya (78%), tangerine (51%), guava (38%), lemon (30%), orange (29%), mango (24%) and avocado (20%). This study provides an important contribution to the knowledge of the ecology of B. carambolae, and the information generated here can be used by government agencies as a decision-making tool to prevent the carambola fruit fly spread across the world.

Co-Infestation and Spatial Distribution of Bactrocera carambolae and Anastrepha spp. (Diptera: Tephritidae) in Common Guava in the Eastern Amazon.

Field infestation and spatial distribution of introduced Bactrocera carambolae Drew and Hancock and native species of Anastrepha in common guavas [Psidium guajava (L.)] were investigated in the eastern Amazon. Fruit sampling was carried out in the municipalities of Calçoene and Oiapoque in the state of Amapá, Brazil. The frequency distribution of larvae in fruit was fitted to the negative binomial distribution. Anastrepha striata was more abundant in both sampled areas in comparison to Anastrepha fraterculus (Wiedemann) and B. carambolae The frequency distribution analysis of adults revealed an aggregated pattern for B. carambolae as well as for A. fraterculus and Anastrepha striata Schiner, described by the negative binomial distribution. Although the populations of Anastrepha spp. may have suffered some impact due to the presence of B. carambolae, the results are still not robust enough to indicate effective reduction in the abundance of Anastrepha spp. caused by B. carambolae in a general sense. The high degree of aggregation observed for both species suggests interspecific co-occurrence with the simultaneous presence of both species in the analysed fruit. Moreover, a significant fraction of uninfested guavas also indicated absence of competitive displacement.

Morphometric Differentiation Among Anastrepha fraterculus (Diptera: Tephritidae) Exploiting Sympatric Alternate Hosts.

Anastrepha fraterculus (Wiedemann) is currently considered a complex of cryptic species infesting fruits from Mexico to Argentina and represents an interesting biological model for evolutionary studies. Moreover, detecting and quantifying behavioral, morphological, and genetic differentiation among populations is also relevant to the application of environment-friendly control programs. Here, phenotypic differentiation among individuals coexisting in the wild in a Northern region of Argentina was unveiled and associated with host choice. Six morphometric traits were measured in sympatric flies exploiting three different host species. Phenotypic variation was shown to be host-dependent regardless of geographical or temporal overlap. Flies collected from synchronous alternate hosts (peach and walnut) differed from each other despite the lack of geographical isolation. By contrast, flies emerging from guavas that ripen about two months later than peach and walnut showed no significant differentiation in comparison to flies collected from walnuts, but they differ significantly from flies originating from peaches. This result is consistent with the hypothesis that the same population of flies shifts from walnuts to guavas throughout the year, whereas the population of flies that uses peaches as a host is probably exploiting other alternate hosts when peach availability decreases. Further research is needed to study the underlying mechanism. Results are consistent with previous molecular markers (inter-simple sequence repeat-ISSR) research on flies stemming from the same hosts and the same area, suggesting that differentiation among flies emerging from alternative hosts occurs at both genetic and phenotypic levels. The contribution of host preference in long-term genetic differentiation is discussed.

Steinernema jeffreyense n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from South Africa.

During a non-targeted survey for entomopathogenic nematodes in South Africa, a new species of Steinernema was isolated from a soil sample collected from underneath a guava tree, close to the shore at Jeffrey's Bay. The nematode was isolated by means of the insect-baiting technique using last-instar larvae of Galleria mellonella. It is described herein as Steinernema jeffreyense n. sp. The nematode can be separated from other described, closely related species in terms of the morphological and morphometric characteristics of the different life stages, and in terms of the characterization and phylogeny of DNA sequences of the internal transcribed spacer (ITS) rDNA of the 18S gene, and of the D2D3 region of the 28S rDNA gene. The new species is placed molecularly in the arenarium-glaseri-karii-longicaudatum group characterized by the following morphological characters: infective third-stage juvenile with a body length of 926 (784-1043) µm, distance from head to excretory pore of 87 (78-107) µm, tail length of 81 (50-96) µm, with an E% of 109 (86-169), and eight evenly spaced ridges (i.e. nine lines) in the middle of the body. First-generation males have a spicule length of 88 (79-95) µm and gubernaculum length of 57 (51-61) µm. Male mucron is absent in both generations. First-generation females have an asymmetrical protuberance and a short, double-flapped epiptygmata, with both flaps directed to the front. The tail of the first-generation female is shorter than the anal body width, with a mucron on the dorsal tail tip, with D% = 78 (59-99). Cross-hybridization with S. khoisanae, S. tophus and S. innovationi showed the new species to isolate reproductively from the others. The analyses of ITS rDNA and D2D3 sequence of the 18S and 28S rDNA genes support the studied nematode isolate to be a valid new species belonging to the 'glaseri' group (Clade V).

Development of Anastrepha fraterculus (Diptera: Tephritidae) Related to the Phenology of Blueberry, Blackberry, Strawberry Guava, and Surinam Cherry Fruits.

Anastrepha fraterculus (Wiedemann, 1830) is the main pest of temperate climate orcharding. The study investigated the development of A. fraterculus related to phenological stage of blueberry, blackberry, strawberry guava, and Surinam cherry trees. The phenological stages I (green fruits), II (intermediate ripening stage of fruits), and III (fruits close to harvesting) were determined, and they are from 8th, 10th, and 11th week; 6th, 8th, and 9th week; 8th, 13th, and 16th week; and 5th, 6th, and 7th week after the first flowering of blueberry, blackberry, strawberry guava, and Surinam cherry trees, respectively. We collected fruits from orchards to determine the infestation index using the formula: number of pupa/fruit weight. To investigate the development of A. fraterculus, we determined the following biological parameters: egg-to-adult period, weight of pupae, oviposition period, fecundity, number of pupae, and number of infested fruits. The infestation index for the fruits collected in the field was greater in strawberry guava and Surinam cherry fruits. In the laboratory, the development of A. fraterculus occurred in stage III of blueberry. In blackberry, besides stage III, we also observed the development in stage II, however, at lower infestation. In strawberry guava, the development of A. fraterulus occurred in stages II and III, and the development in both stages was similar. For Surinam cherry, the development occurred in the three phenological stages with similar values for biological parameters. Overall, of the four hosts studied, the strawberry guava and Surinam cherry fruits allowed a better biological development of A. fraterculus, corroborating its preference for fruits native to Brazil.

Limits to the host range of the highly polyphagous tephritid fruit fly Anastrepha ludens in its natural habitat.

Anastepha ludens (Diptera: Tephritidae) is a highly polyphagous fruit fly that is able to develop in a wide range of hosts. Understanding the limits of this pest's host range could provide valuable information for pest management and plant breeding for pest resistance. Previous studies have shown that guavas (Psidium guajava (Myrtaceae) L.), are not attacked under natural conditions by A. ludens. To understand this phenomenon, guavas were exposed to natural infestation by A. ludens and to other fruit fly species that infest guavas in nature (Anastrepha striata Schiner, Anastepha fraterculus (Wiedemann), Anastepha obliqua (Macquart)). Once the susceptible phenological stage of guavas was determined, fruit infestation levels were compared between A. ludens and A. striata. Choice and non-choice tests were performed under field-cage conditions. Under field conditions, guavas were susceptible to A. striata and A. fraterculus attack all the way from when fruit was undeveloped to when fruit began to ripen. No infestation by A. ludens was recorded under natural conditions. Similar results were obtained when forced exposures were performed, indicating that unripe guavas were preferred by A. striata over ripe fruit, and that infestation rates were higher at early fruit maturity stages. Under forced oviposition conditions, A. ludens larvae were unable to develop in unripe guavas but did so in fully ripe fruit. However, A. ludens fitness parameters were dramatically affected, exhibiting reduced survival and reduced pupal weight compared to conspecifics that developed in a natural host, grapefruit. We confirm that P. guajava should not be treated as a natural host of this pestiferous species, and suggest that both behavioral aspects and the fact that larvae are unable to adequately develop in this fruit, indeed represent clear limits to A. ludens's broad host range.

Root based responses account for Psidium guajava survival at high nickel concentration.

The presence of Psidium guajava in polluted environments has been reported in recent studies, suggesting that this species has a high tolerance to the metal stress. The present study aims at a physiological characterization of P. guajava response to high nickel (Ni) concentrations in the root-zone. Three hydroponic experiments were carried out to characterize the effects of toxic Ni concentrations on morphological and physiological parameters of P. guajava, focusing on Ni-induced damages at the root-level and root ion fluxes. With up to 300µM NiSO4 in the root-zone, plant growth was similar to that in control plants, whereas at concentrations higher than 1000µM NiSO4 there was a progressive decline in plant growth and leaf gas exchange parameters; this occurred despite, at all considered concentrations, plants limited Ni(2+) translocation to the shoot, therefore avoiding shoot Ni(2+) toxicity symptoms. Maintenance of plant growth with 300µM Ni(2+) was associated with the ability to retain K(+) in the roots meanwhile 1000 and 3000µM NiSO4 led to substantial K(+) losses. In this study, root responses mirror all plant performances suggesting a direct link between root functionality and Ni(2+) tolerance mechanisms and plant survival. Considering that Ni was mainly accumulated in the root system, the potential use of P. guajava for Ni(2+) phytoextraction in metal-polluted soils is limited; nevertheless, the observed physiological changes indicate a good Ni(2+) tolerance up to 300µM NiSO4 suggesting a potential role for the phytostabilization of polluted soils.

Multiplex PCR in determination of Opiinae parasitoids of fruit flies, Bactrocera sp., infesting star fruit and guava.

Malaysia is a tropical country that produces commercial fruits, including star fruits, Averrhoa carambola L. (Oxalidales: Oxalidaceae), and guavas, Psidium guajava L. (Myrtales: Myrtaceae). There is a high demand for these fruits, and they are planted for both local consumption and export purposes. Unfortunately, there has been a gradual reduction of these fruits, which has been shown to be related to fruit fly infestation, especially from the Bactrocera species. Most parasitic wasps (Hymenoptera: Braconidae: Opiinae) are known as parasitoids of fruit fly larvae. In this study, star fruits and guavas infested by fruit fry larvae were collected from the Malaysian Agricultural Research and Development Institute. The parasitized larvae were reared under laboratory conditions until the emergence of adult parasitoids. Multiplex PCR was performed to determine the braconid species using two mitochondrial DNA markers, namely cytochrome oxidase subunit I and cytochrome b. Two benefits of using multiplex PCR are the targeted bands can be amplified simultaneously using the same reaction and the identification process of the braconid species can be done accurately and rapidly. The species of fruit flies were confirmed using the COI marker. The results obtained from our study show that Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae), Fopius arisanus (Sonan), and Pysttalia incisi (Silvestri) were parasitoids associated with Bactrocera carambolae (Drew and Hancock) (Diptera: Tephritidae) infested star fruits. Fopius arisanus was also the parasitoid associated with Bactrocera papayae (Drew and Hancock) infested guavas. Maximum parsimony was been constructed in Opiinae species to compare tree resolution between these two genes in differentiating among closely related species. The confirmation of the relationship between braconids and fruit fly species is very important, recognized as preliminary data, and highly necessary in biological control programs.

Predicting plant invasions under climate change: are species distribution models validated by field trials?

Climate change may facilitate alien species invasion into new areas, particularly for species from warm native ranges introduced into areas currently marginal for temperature. Although conclusions from modelling approaches and experimental studies are generally similar, combining the two approaches has rarely occurred. The aim of this study was to validate species distribution models by conducting field trials in sites of differing suitability as predicted by the models, thus increasing confidence in their ability to assess invasion risk. Three recently naturalized alien plants in New Zealand were used as study species (Archontophoenix cunninghamiana, Psidium guajava and Schefflera actinophylla): they originate from warm native ranges, are woody bird-dispersed species and of concern as potential weeds. Seedlings were grown in six sites across the country, differing both in climate and suitability (as predicted by the species distribution models). Seedling growth and survival were recorded over two summers and one or two winter seasons, and temperature and precipitation were monitored hourly at each site. Additionally, alien seedling performances were compared to those of closely related native species (Rhopalostylis sapida, Lophomyrtus bullata and Schefflera digitata). Furthermore, half of the seedlings were sprayed with pesticide, to investigate whether enemy release may influence performance. The results showed large differences in growth and survival of the alien species among the six sites. In the more suitable sites, performance was frequently higher compared to the native species. Leaf damage from invertebrate herbivory was low for both alien and native seedlings, with little evidence that the alien species should have an advantage over the native species because of enemy release. Correlations between performance in the field and predicted suitability of species distribution models were generally high. The projected increase in minimum temperature and reduced frosts with climate change may provide more suitable habitats and enable the spread of these species.

Maintenance of a living understory enhances soil carbon sequestration in subtropical orchards.

Orchard understory represents an important component of the orchards, performing numerous functions related to soil quality, water relations and microclimate, but little attention has been paid on its effect on soil C sequestration. In the face of global climate change, fruit producers also require techniques that increase carbon (C) sequestration in a cost-effective manner. Here we present a case study to compare the effects of understory management (sod culture vs. clean tillage) on soil C sequestration in four subtropical orchards. The results of a 10-year study indicated that the maintenance of sod significantly enhanced the soil C stock in the top 1 m of orchard soils. Relative to clean tillage, sod culture increased annual soil C sequestration by 2.85 t C ha(-1), suggesting that understory management based on sod culture offers promising potential for soil carbon sequestration. Considering that China has the largest area of orchards in the world and that few of these orchards currently have sod understories, the establishment and maintenance of sod in orchards can help China increase C sequestration and greatly contribute to achieving CO2 reduction targets at a regional scale and potentially at a national scale.

Odour-active compounds in guava (Psidium guajava L. cv. Red Suprema).

BACKGROUND: Solid phase microextraction and simultaneous distillation-extraction combined with GC-FID, GC/MS, aroma extract dilution analysis and odour activity values were used to analyse volatile compounds from guava (Psidium guajava L. cv. Red Suprema) and to estimate the most odour-active compounds. RESULTS: The analysis led to the detection of 141 compounds, 121 of which were positively identified. The composition of guava fruit volatiles included 43 esters, 37 terpenes, 18 aldehydes, 16 alcohols, ten acids, six ketones, four furans and seven miscellaneous compounds. CONCLUSION: Seventeen odorants were considered as odour-active compounds, with (E)-ß-ionone, ethyl hexanoate, ethyl butanoate, hexanal, (Z)-3-hexenal, hexyl acetate, (E)-2-hexenal and limonene contributing most to the typical guava aroma of this cultivar.

The guava tree as bioindicator during the process of fuel replacement of an oil refinery.

This study was performed to verify whether the exchange of the fuel used in the boilers of a crude oil refinery located in Cubatão (SE Brazil) would result in alterations on gas exchange, growth and leaf injuries in saplings of Psidium guajava 'Paluma'. The purpose of the refinery was to reduce the SO2 emission, but using natural gas as fuel could increase the concentrations of O3 precursors in the atmosphere. Thus a biomonitoring was performed with a native species sensitive to O3. The plants were exposed in five areas (CM1, CM5, CEPEMA, Centro, and RP) at different distances to the refinery, both before and after the fuel exchange. We performed six exposures under environmental conditions, with length of ca. 90 days each. With the utilization of natural gas, the saplings presented reductions in carbon assimilation rate under saturating light conditions (Asat, µmolCO2m(-2)s(-1)) and the stomatal conductance (gs, molH2Om(-2)s(-1)), and increase in height, number of leaves, and dry mass of leaves and shoots. There were also reductions in root dry mass and in the root/shoot ratio. The saplings also presented O3-induced leaf injuries. The responses of P. guajava 'Paluma' were altered after the fuel exchange as a result of a new combination of pollutants in the atmosphere. The fuel exchange has not resulted in environmental benefit to the surrounding forest; it has only altered the contamination profile of the region.

Biology and systematics of gall-inducing triozids (Hemiptera: Psylloidea) associated with Psidium spp. (Myrtaceae).

Psidium myrtoides (Myrtaceae) shelters the gall inducer Nothotrioza myrtoidis gen. et sp. n. (Hemiptera: Psylloidea) which is described and illustrated here. Nothotrioza belongs to the family Triozidae and is probably most closely related to Neolithus, a monotypic Neotropical genus associated with Sapiun (Euphorbiaceae). Three species are recognized within Nothotrioza: the type species N. myrtoidis sp. n. associated with Psidium myrtoides, N. cattleiani sp. n. (misidentified by Butignol & Pedrosa-Macedo as Neotrioza tavaresi) with Psidium cattleianum, and N. tavaresi (Crawford) comb. n. (from Neotrioza) with an unidentified species of Malpighiaceae, respectively. A lectotype is designated here for Neotrioza tavaresi. Also, the diversity of insect galls associated with P. myrtoides and the biology of N. myrtoidis were examined. N. myrtoidis presents five instars and an annual life cycle synchronised with the phenology of P. myrtoides. Gall size was proportional to the insect developmental stages, and rates of parasitism and mortality were 15.7 % and 29.8 %, respectively. The red colour is an important macroscopic diagnostic feature of the gall that could be associated with parasite-free condition of the galling insect. The biological features presented by the system Psidium myrtoides--Nothotrioza myrtoidis are in accordance with other systems involving sucking galling insects, however, it is exceptional by its univoltine life cycle associated with a perennial plant in the Neotropics. The galls induced by the three known Nothotrioza spp. are morphologically similar, i.e. closed, globoid and unilocular, as well as the opening mechanism for releasing the adults.

Somatic embryogenesis for efficient micropropagation of guava (Psidium guajava L.).

Guava (Psidium guajava L.) is well known for edible fruit, environment friendly pharmaceutical and commercial products for both national and international market. The conventional propagation and in vitro organogenesis do not meet the demand for the good quality planting materials. Somatic embryogenesis for efficient micropropagation of guava (P. guajava L.) has been developed to fill up the gap. Somatic embryogenesis and plantlets regeneration are achieved from 10-week post-anthesis zygotic embryo explants by 8-day inductive treatment with different concentrations of 2,4-dichlorophenoxy acetic acid (2,4-D) on MS agar medium containing 5% sucrose. Subsequent development and maturation of somatic embryos occur after 8 days on MS basal medium supplemented with 5% sucrose without plant growth regulator. The process of somatic embryogenesis shows the highest relative efficiency in 8-day treatment of zygotic embryo explants with 1.0 mg L(-1) 2,4-D. High efficiency germination of somatic embryos and plantlet regeneration takes place on half strength semisolid MS medium amended with 3% sucrose within 2 weeks of subculture. Somatic plantlets are grown for additional 2 weeks by subculturing in MS liquid growth medium containing 3% sucrose. Well-grown plantlets from liquid medium have survived very well following 2-4 week hardening process. The protocol of somatic embryogenesis is optimized for high efficiency micropropagation of guava species.

Productividad y selectividad del medio de cultivo a partir de guayaba agria (psidium araca) en el crecimiento de levaduras nativas del género candida sp / Productivity and selectivity of culture medium from the sour guava (psidium araca) in the growth of native yeast candida sp

El presente trabajo se llevó a cabo para evaluar la eficiencia del medio de cultivo a partir de guayaba agria (Psidium araca) frente a medios comerciales en el crecimiento de tres cepas nativas: Candida guillermondii, Candida famita y Candida sp. Se evaluó el crecimiento microbiano a diferentes concentraciones de fruta, 5, 10, 25 y 50% p/v, tomando como control los medios comerciales: Malta, Sabouraud y agar papa dextrosa (PDA). La productividad y selectividad del medio de guayaba agria fue determinada mediante el método Ecométrico en un tiempo de 48 horas. Los análisis estadísticos aplicados para evaluar y comparar el crecimiento de las cepas en los medios comerciales y en el medio de guayaba agria a diferentes concentraciones demostraron lo siguiente: Candida guillermondii presentó crecimiento mayor o igual a 25 y 50% p/v comparado con los medios comerciales; Candida famata y Candida sp presentaron mejores crecimientos al 5% p/v, con respecto a los diferentes medios comerciales. Los resultados demostraron que el medio de cultivo es altamente productivo y no selectivo, lo que representa una alternativa en la conservación, el mantenimiento y el desarrollo de las levaduras estudiadas.

This work was carried out to evaluate the efficiency of the culture medium from sour guava (Psidium araca) against commercial media in the growth of three native strains: Candida guillermondii, Candida famata and Candida sp. Microbial growth was evaluated at different concentrations of fruit, 5, 10, 25, 50% w /v, using as control the commercial media: Malta, Sabouraud and PDA (Potato Dextrose Agar). The productivity and selectivity of the sour guava medium was determined by the Ecometric method in a time of 48 hours. The applied statistical analysis to evaluate and compare growth of strains in commercial culture medium and in the medium from sour guava at different concentrations showed: Candida guillermondii grew greater than or equal to 25 and 50% w / v compared with commercial medium, Candida famata and Candida sp showed better growth at 5% w / v, with respect to commercial medium. The results showed that the medium is highly productive and non-selective representing an alternative to the conservation, maintenance and development of the yeasts.