Byrsonima Verbascifolia Research Articles

Floral visitors of the muricizeiro Byrsonima verbascifolia (L.) rich in the Atlantic forest of northeast Brazil

The muric tree (Byrsonima verbascifolia (L.) Rich) is a native fruit plant used by humans for various purposes, from edible fruits to the medicinal uses of its leaves, bark, and fruits. Bees are the main pollinators of wild and cultivated plants, and without pollination, there is no formation of fruits and seeds, so floral visitors perform ecosystem services in exchange for pollen, nectar, and oil. Muricizeiro offers pollen and oils to its floral visitors, which attracts several species of native bees to its inflorescences, mainly Centris and Epicharis bees, specialists in oil collection. Thus, the presence of muric trees close to the planting area can contribute to the pollination of the cultivated plants. The objective of this study was to survey floral visitors to muricizeiro in São Cristóvão. The work was carried out in the Emília Maria settlement in São Cristóvão, Sergipe, where the floral visiting bees of muricizeiro were captured with an entomological net, for ten days, in the morning and afternoon. Twelve bee species belonging to the Apidae and Halictidae families were collected, with the most abundant species being Euglossa chalybeata (38.41%) and Eulaema nigrita (25.42%). The presence of Eulaema nigrita is related to environmental changes during the implementation of agriculture. The specimens were deposited in the entomological collection of the IFS/Campus São Cristóvão.

Murici (Byrsonima verbascifolia): A high bioactive potential fruit for application in cereal bars

In order to popularize and use murici fruit (Byrsonima verbascifolia) in processed foods, the aim of the study was to characterize the fresh fruit as to its antioxidant capacity, volatile and bioactive compounds and to evaluate the effect of murici content on total carotenoids and sensory attributes in enriched cereal bars. For the development of cereal bars, a Plackett-Burman design was elaborated, containing eight independent variables: glucose syrup, oats in thick flakes, corn flakes, rice flakes, dehydrated murici, soy lecithin, hydrogenated vegetable fat, and brown sugar. Fresh murici were characterized for proximate composition, total and individual carotenoids, antioxidant capacity, volatile compounds, and microbiological analysis. The murici was mainly a good source of fiber (6.4%) and lipids (7.3%), with significant levels of total carotenoids (15.3 μg of β-carotene/g) and antioxidant capacity by FRAP method and ABTS method. The volatile fraction of murici mainly contains esters with descriptors such as cheese and fruity. The experimental design used helped obtain the formulations of cereal bars with murici and demonstrated that the content of carotenoids increases as the amount of added fruit increases.

Bioactivity and bioaccessibility of phenolic compounds from Brazilian fruit purees

In this study, the phenolic content, antioxidant capacity, antimicrobial activity and bioaccessibility in different fruit purees were evaluated. Strawberry (Fragaria ananassa Duch.), starfruit (Averrhoa carambola) and other fruits native from Brazil, such as açaí (Euterpe oleracea), acerola (Malpighia emarginata), araçá (Psidium guineenses), cambuci (Campomanesia phaea), jabuticaba (Myrciaria cauliflora), murici (Byrsonima verbascifolia), panã (Annona crassiflora) and pitanga (Eugenia uniflora) were evaluated. Among the fruits studied, acerola exhibited high antioxidant activity and high concentration of total phenolic compounds. Individual bioactive compounds were determined by UPLC-QToF-MS. A wide range of organic acids, flavonoids and phenolic acids were found in the samples. Fruit puree extracts (6–25 mg/mL) inhibited bacterial growth, especially those from strawberry, acerola, starfruit and pitanga. Overall, up to 8% of the TPC were bioaccessible after gastrointestinal digestion. The findings support the notable potential of fruit purees as sources of bioactive compounds of industrial interest.

How does mistletoe infection affect seasonal physiological responses of hosts with different leaf phenology?

Plants should have the ability to perceive physiological changes within their branches when infected by mistletoes, adjusting the use of resources between infected and uninfected branches which can be crucial for their survival in the long-term. Here we investigated how branches infected by the mistletoe Passovia ovata (Pohl ex DC.) Tiegh. and uninfected branches within the same individual tree respond to seasonal environmental changes across two hosts of contrasting leaf phenology (the evergreen Miconia albicans (SW.) Triana and the deciduous Byrsonima verbascifolia (L.) DC.). We measured key leaf traits (instantaneous gas exchange rates, diurnal courses of stomatal conductance, leaf water potential, specific leaf area and leaf macronutrient concentrations) during the peak of the wet and dry season in a seasonal savanna of central Brazil. Pre-dawn leaf water potentials were consistently more negative for infected branches of both hosts, suggesting that overnight water refilling of infected branches was more limited. However, infected and uninfected branches exhibited similar leaf water potentials at midday, suggesting that they undergo similar imbalances in water supply and demand during periods of high atmospheric evaporative demand. Infected and non-infected branches of the evergreen mistletoe showed tighter regulation of water loss, whereas infected branches of the deciduous host were less constrained in regulating leaf transpiration. We also found differences for nutrient concentrations: N, P and K were lower, while Ca was higher in leaves of infected branches. Physiological changes induced by mistletoe infection affected host performance, and were reflected in water and nutrient use differences between infected and uninfected branches. Our findings show that infection responses by mistletoes can be detected between branches within individual trees, and that host species with distinct patterns of leaf phenology are capable to adjust, at the individual level, to cope with mistletoe's imposed physiological stress throughout the year.

A novel trophobiotic interaction between a Neotropical stink bug and an ant species: Insights into potential benefits to the host plant

Trophobiotic interactions occur when phytophagous insects provide a sugary liquid, the honeydew, for ants and obtain defence against predators or parasitoids. The plants may indirectly benefit from an increased ant foraging activity by reducing the herbivorous abundance. These three trophic interactions have been previously studied for several species, but mainly involving plants with extrafloral nectaries, which is a plant structure that also produce attractive substances for ants. Previous studies have reported an ant preference for honeydew over extrafloral nectary content. Therefore, trophobiosis can be an important mediator of ant-plant interactions. In this study, we describe a trophobiotic interaction between Edessa contermina stink bugs and Camponotus blandus ants on the Byrsonima verbascifolia plants occurring in a conservation area of Brazilian savanna. Stink bugs excreted a sugary liquid which was consumed by the ants, and C. blandus ants were observed consuming potential parasitoids. Stink bugs were more abundant in plants containing high food supply and shelter availability. The occurrence of ants depended of the number of inflorescences and trunk circumference of B. verbascifolia. Ant abundance, however, was positively correlated with stink bug abundance and the number of inflorescences. Herbivory was not explained by neither plant architecture nor ant abundance. This high ant activity may benefit plants from a protection against herbivory, but we did not detect this effect during the study period. Hence, the interaction among ants and plants was apparently commensal. We concluded that plant traits were important in ant attraction, but stink bugs foraging also increased ant activity on the plant, but mainly on inflorescences. Therefore, the plant may benefit from an increased defence of inflorescences rather than leaves.

Structure and composition of the insect community associated with flower buds and inflorescences of Byrsonima verbascifolia (Malpighiaceae)

ABSTRACT The threat addressed to tropical biomes such as the Brazilian Cerrado leads to an urgent need for understanding the natural history of plant-insect interactions within ecosystems. Byrsonima verbascifolia is an evident Cerrado plant found to be economically and culturally important. This plant species is commonly found in that biome, showing a close association with insects since their flower buds and inflorescences contain attractive oil glands for a wide variety of them. In this study, we investigated whether communities of flower-visiting insects and ants associated with B. verbascifolia in the flower bud phase differ from those in the flowering phase. The abundance, richness and diversity of insect visitors to flower buds were similar in relation to inflorescences. However, low similarity of the composition of bud/inflorescence-visiting insects was observed. On the other hand, ants associated with plants in the anthesis phase showed a significantly higher abundance in relation to plants with flower buds, although the diversity was similar in both phases. Ant richness was higher in plants containing greater proportions of open inflorescences than buds, although this difference was only marginally significant. The ant community similarity in plants with buds and inflorescences was higher. Results suggest that different available resources (oil, pollen and petals) in buds and inflorescences of B. verbascifolia recruit a community of insect visitors with distinct composition, which was less affected in relation to the ant community. These findings show that visitors and ants do not use the same flower resource, once there are differences in terms of resources available in both flower buds and inflorescence stages.

α-Glucosidase and non-enzymatic glycation inhibitory potential of Eugenia dysenterica fruit pulp extracts

Considering the nutritional benefits of fruits on human health, this study aimed to screen 11 fruits found in the Brazilian Savanna for glycoside hydrolases inhibitors with antioxidant and anti-glycation properties. Aqueous and ethanol extracts of pulps were used in enzymatic assays to evaluate the inhibitory potential against α-amylase and α-glucosidase, as well as antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays) and anti-glycation (BSA-fructose model) capacities. Ethanol extracts of Campomanesia xanthocarpa, Byrsonima verbascifolia and Eugenia dysenterica had the lowest DPPH IC50 values (<0.25 mg/ml), while ethanol extracts of Genipa americana and B. verbascifolia had the highest ORAC values (>0.60 mmol trolox equivalents/g). The extracts of E. dysenterica showed potential to inhibit glycation (IC50 < 0.40 mg/ml) and α-glucosidase (IC50 < 20 μg/ml). Liquid-liquid fractionation of the extracts of E. dysenterica fruit pulp resulted in the ethyl acetate fraction showing higher antioxidant (DPPH IC50 10 μg/ml and ORAC 1.3 mmol trolox equivalents/g) and anti-glycation (IC50 0.10 mg/ml) capacities, and α-glucosidase inhibition activity (IC50 11 μg/ml). HPLC-ESI-MS/MS analysis suggested the presence of antioxidant molecules in E. dysenterica fruit pulp, such as ferulic and gallic acids, myricetin, quercetin and kaempferol-pentosides. Non-conventional fruits found in the Brazilian Savanna, a global biodiversity hotspot, with antioxidant and anti-glycation properties, could be potential sources of nutraceuticals to combat oxidative stress, which is present in many pathologies. In addition, the capacity of E. dysenterica to inhibit α-glucosidase and non-enzymatic glycation makes it especially useful for in vivo studies related to diabetes mellitus.

Caracterização física e química de gabiroba e murici

The knowledge of the physical and chemical characteristics of the Cerrado fruits is of fundamental importance, from the commercial point of view, to add value and quality to the final product. Thus, the present work aimed to evaluate the physical and chemical characteristics of gabiroba fruits (Campomanesia adamantium (Cambess.) O. Berg) and murici (Byrsonima verbascifolia (L.) Rich). Fruit samples were collected in 12 matrices with 25 fruits per matrix for both species. The physical characteristics of fruits and seeds were evaluated: longitudinal and transverse diameter, and mass. The chemical characteristics studied were: pH, soluble solids, acidity in citric acid, humidity and ashes. Fruits of gabiroba presented average values ​​of: longitudinal length (13.99 mm); transverse (14.40 mm); mass of the fruit (2.359 g); pH (3.767); soluble solids (11.78°Brix); acidity in citric acid (11.20 mg g -1), humidity (78.24%); and ashes (21.40%). It was observed that the physical variables evaluated in fruits of murici obtained the respective values ​​for longitudinal length (14.53 mm); transverse (15.36 mm); and mass of the fruit (2.61 g). The matrices 3, 6, 8 and 12 of murici produced fruits with higher soluble solids contents, whose values ​​were: 12.12; 11.42; 11.55; and 10.29°Brix.

Relationships between moisture content and flammability of campestral Cerrado species in Jalapão

The objective of this study was to analyze the relationships between moisture content and the flammability of campestral Cerrado species in the Jalapao region. For that, six species were collected (Trachypogon spicatus, Aristida sp., Davilla elliptica, Byrsonima verbascifolia, Hirtella ciliata and Dalbergia miscolobium) and analyzed in four moisture levels (H1, H2, H3 and H4). The tests were performed in the epirradiator, with 50 replicates of 1 g sample for each species, to obtain the ignition frequency (IF), the mean time to ignition (MTI), the time of combustion (MTC) and flame height (MFH). Correlations between moisture and other variables were r = 0.94 (MTI), r = -0.43 (MTC), r = -0.87 (MFH) and r = -0.73 (IF). The linear regression equations had R²aj values of 0.87 (MTI); 0.15 (MTC); 0.74 (MFH) and 0.50 (IF). There was influence of humidity in the change of flammability variables, however, there was little variation in the flammability values (FV), except for the species Aristida sp., and Dalbergia miscolobium, showing the high flammability of most species, even at the highest levels of moisture content.

Fingerprinting metabolomics in tropical mistletoes: A case study with facultative aluminum-accumulating species

Aluminum (Al) toxicity is a hot topic due to the high sensitivity of cultivated plants. Despite the large investment in the last century in understanding the mechanisms used by sensitive and Al-excluding species to avoid Al uptake from soil, little attention has been devoted to understanding the mechanisms used by native Al-accumulating species to deal with Al-toxicity. Passovia ovata (Pohl ex DC.) Kuijt and Struthanthus polyanthus Mart. are mistletoes with a facultative Al-accumulating behavior. In the Brazilian Cerrado they are commonly found infecting Al-accumulating (Miconia albicans (Sw.) Steud.) and non-accumulating (Byrsonima verbascifolia (L.) DC.) species. Taking into account the importance of organic complexes in the detoxification of the highly toxic Al3+ ions, it is to be expected that mistletoes differ in their metabolomic profile when feeding on species differing in Al accumulation. Here we tested this hypothesis using an untargeted LC–MS approach to investigate the influence of Al on the metabolome of P. ovata and S. polyanthus infecting M. albicans and B. verbascifolia under field conditions. We observed differences in the metabolic profiles between mistletoes growing on Al-accumulating and Al-excluding hosts, and also observed a positive correlation between Al leaf-accumulation and the metabolic profile. Using the OPLS-DA, we identified quinic acid (phenolic compound) as a metabolic biomarker distinguishing mistletoes grown under high and low Al availability.

Mechanisms of storage and detoxification of Al in two tropical mistletoes

Passovia ovata (Pohl ex DC.) Kuijt and Struthanthus polyanthus Mart. are hemiparasitic mistletoes that can grow on Al-accumulating and Al-excluding woody species in the Brazilian Cerrado. It is unclear to what extent this hemiparasitic lifestyle implies facultative Al accumulation by the mistletoes and if so, what are the Al tolerance mechanisms in these species. Using a field-work experiment composed by two facultative Al-accumulating mistletoe species (P. ovada and S. polyanthus) infecting Al-accumulating (Miconia albicans (Sw.) Steud.) and Al-excluding (Byrsonima verbascifolia (L.) DC.) hosts, we (1) investigated Al accumulation and leaf nutritional status of the mistletoes, (2) characterized the storage sites and the forms of Al accumulated in their leaves, and (3) determined differences in levels of simple organic acids associated with Al detoxification. Leaf nutrients and Al accumulation in mistletoes followed the host elements availability. In both mistletoe species infecting the Al-accumulating host M. albicans, Al was mainly allocated to the phloem fibres, and Al-citrate was the main form of Al. Contrastingly, in the hosts’ leaves Al was present mainly in the form of oxalate complexes. When growing on B. verbascifolia, the Al excluding host, the two mistletoes neither showed symptoms of Al storage nor formation of Al-organic acid complexes. In conclusion, mistletoes growing on Al-accumulating trees tolerate high Al tissue levels by allocating Al in phloem fibres and by its chelation with citrate.

Environmental conditions modulate plasticity in the physiological responses of three plant species of the Neotropical savannah

Plasticity in plants could be changed due to abiotic factors, tending to increase fitness across environments. In the Neotropical savannah, a strong water deficit during the dry season is one of the main factors limiting the plasticity in physiological responses of plants. The present study aims to assess the plasticity in physiological responses and vegetative phenology of three plant species of the Neotropical savannah (Cerrado in Brazil) during the dry and the rainy seasons. The three species, Byrsonima verbascifolia, Roupala montana, and Solanum lycocarpum, occur in Serra do Cipo in the state of Minas Gerais, Brazil. The development and vegetative phenology of individuals of these three species were evaluated over the course of 1 year. In February 2012 (rainy season) and August 2012 (dry season), stomatal conductance (g s), water potential (Ψ), photosynthetic quantum yield, and concentration of leaf photosynthetic pigments were measured. The relative distance among the physiological parameters of all individuals within each season was measured using the relative distance plasticity index. B. verbascifolia has pronounced senescence in July and lost leaves completely by the early September, while R. montana and S. lycocarpum have green leaves throughout the year. The three studied species had greater control of stomatal opening during the dry season. S. lycocarpum and R. montana had negative water potential values in the dry season and in the middle of the day in both seasons. In the dry season, the three species exhibited a decrease in F v/F m, with values between 0.7 and 0.75. The relative distance plasticity index varied from 0 to 1. R. montana demonstrated the greatest plasticity and S. lycocarpum had lower plasticity. Then, a seasonal effect on physiological response was observed in all three model-species, with lower values for leaf water potential and stomatal conductance, and increased photoinhibition, in the dry season. Ecophysiological traits, such as stomatal conductance and leaf water potential, exhibited the greatest plasticity. In addition, there was a seasonal effect on the plasticity in physiological responses of the three plants species of the Neotropical savannah. The results are contradicting the idea that water restriction in the dry season would reduce the plasticity in most species of the Neotropical savannah.

Effect of extraction following different drying times on the viability of Byrsonima verbascifolia seeds

Effect of extraction following different drying times on the viability of Byrsonima verbascifolia seeds

Food, shelter or competitors? Overlapping of life stages and host plant selection in a Neotropical stink bug species

ABSTRACTPhytophagous insects may choose host plants based on conditions that enhance offspring performance. However, some insect species may also select plants based on attributes that enhance their own performance regardless of the consequences for offspring survival. An approach evaluating both hypotheses could provide a more comprehensive understanding of the host plant selection by phytophagous insects. In this study, we described the life stages of a Neotropical stink bug, Edessa contermina, co-occurring on Byrsonima verbascifolia plants in a conservation area of the Brazilian Savannah. We also empirically evaluated how food supply, shelter availability and competitors’ density on the host plants affected the densities of nymphs, adults and mating pairs. We identified and described five life stages of E. contermina. The amount of plant resources did not explain the nymph, adult and mating pairs’ density. However, adults and mating pairs chose plants with a low density of nymphs, probably because egg laying on the host plants with a high density of competitors may negatively affect offspring performance.

Peripheral and central antinociceptive effects of the butanolic fraction of Byrsonima verbascifolia leaves on nociception-induced models in mice.

Byrsonima verbascifolia (Malpighiaceae), commonly known as 'murici', is used in folk medicine, for example, in the treatment of inflammation. The anti-inflammatory activity of the butanolic fraction of B. verbascifolia leaves (BvBF) was previously reported by our group, and the present study was designed to evaluate their antinociceptive effects. BvBF (25, 50, and 100mg/kg) administered intraperitoneally (i.p.) inhibited acetic acid induced abdominal writhing. In the formalin test, BvBF (10, 30 and 100mg/kg, i.p.) caused a reduction in licking time in both the neurogenic and inflammatory phases. Moreover, we demonstrated that BvBF (30 and 100mg/kg, i.p.) caused an increase in the latency to response in the hot-plate test. These results demonstrate that BvBF possesses marked peripheral and central antinociceptive activities. Pre-treatment with the non-selective receptor antagonist naloxone (5mg/kg, i.p.) abolished the antinociceptive effects of BvBF (100mg/kg, i.p.) in the neurogenic phase of the formalin and hot-plate tests. The anti-inflammatory activity of BvBF (previously reported) as well as the participation of the opioidergic system seems to be responsible, at least in part, for these antinociceptive effects. Finally, BvBF at the doses investigated (25, 50 and 100mg/Kg) did not cause any toxicity signals, showing that the antinociceptive activity is devoid of sedative and hypomotility effects.

Leaf histochemistry analysis of four medicinal species from Cerrado

Chemical components act in plant defense and protection, but many of them are extracted and used medicinally. For Cerrado, active chemical components are used in the treatment of diseases, which strengthens the necessity for pharmacological studies of plants of that environment. The objective was to evaluate the histochemistry of the leaf blade of Byrsonima verbascifolia (L.) DC., Malpighiaceae, Campomanesia adamantium (Cambess.) O.Berg, Myrtaceae, Roupala montana Aubl., Proteaceae, and Solanum lycocarpum A. St.-Hil., Solanaceae, species that have been reported as producers of secondary metabolites for pharmacological use. The 3rd node leaves (median, intercostal and margin regions) were collected, fixed, included in Paraplast® or 2-hydroxyethyl methacrylate, sectioned in microtome, stained and photographed on microscope. This analysis aimed to find leaf regions which produced chemical compounds. For histochemical tests, intercostal areas were selected from median region leaf of the 3rd node. Samples fresh and newly collected and fixed and embedded in Paraplast® were used. Tests were conducted for lipids, terpenoids, phenolic compounds, alkaloids, sugars and proteins. Alkaloids were observed only in R. montana, as well as the results for phenolic compounds. Flavonoids are present in B. verbascifolia and R. montana. The lipid composition was showed for the chemical compounds of B. verbascifolia and C. adamantium, which proved to be part of the essential oils or resins oils in C. adamantium idioblasts. The chemical compounds of B. verbascifolia, C. adamantium and R. montana are present mainly in idioblasts among the parenchyma and epidermal cells. C. adamantium has secretory cavities, but only with lipid content. The identification of chemical compounds has not been possible in mature leaves of S. lycocarpum.

Anti-inflammatory effects of the butanolic fraction of Byrsonima verbascifolia leaves: Mechanisms involving inhibition of tumor necrosis factor alpha, prostaglandin E2 production and migration of polymorphonuclear leucocyte in vivo experimentation

The leaves of Byrsonima verbascifolia (Malpighiaceae) are traditionally used to treat various diseases including inflammatory conditions. The main goal of this study was to evaluate the in vivo anti-inflammatory activity of the polar constituents from the butanolic fraction of B. verbascifolia leaves (BvBF), as well as to investigate the mechanisms involved in the anti-inflammatory activity. The polar constituents were identified by liquid chromatography coupled to diode array detector and mass spectrometry (LC-DAD–MS) and matrix-assisted laser desorption/ionization – time-of-flight mass spectrometry (MALDI-TOF MS) to obtain a complete chemical profile of the fraction. Forty-five compounds were detected in the BvBF by LC-DAD–MS/MS, including condensed tannins, phenolic acids, flavonoids (flavones and flavonols) and other compounds. In addition, several condensed tannins were identified by MALDI-MS/MS, which are composed predominantly by procyanidin units (PCY) and up to six flavan-3-ol units. The BvBF exhibited significant antioxidant and anti-inflammatory activities. The BvBF inhibited paw edema and polymorphonuclear (PMN) leukocyte migration to the footpad and pleural cavity induced by carrageenan. Furthermore, a minor dose (12.50mg/kg) of BvBF effectively decreased tumor necrosis factor alpha (TNF-α) and prostaglandin E2 (PGE2) levels in the footpad. These findings suggest that the mechanism of the anti-inflammatory action in the BvBF is linked to the inhibition of the production of inflammatory mediators such as TNF-α and PGE2 and the PMN cell migration.

Leaf morphophysiology of a Neotropical mistletoe is shaped by seasonal patterns of host leaf phenology.

Several mistletoe species are able to grow and reproduce on both deciduous and evergreen hosts, suggesting a degree of plasticity in their ability to cope with differences in intrinsic host functions. The aim of this study was to investigate the influence of host phenology on mistletoe water relations and leaf gas exchange. Mistletoe Passovia ovata parasitizing evergreen (Miconia albicans) hosts and P. ovata parasitizing deciduous (Byrsonima verbascifolia) hosts were sampled in a Neotropical savanna. Photosynthetic parameters, diurnal cycles of stomatal conductance, pre-dawn and midday leaf water potential, and stomatal anatomical traits were measured during the peak of the dry and wet seasons, respectively. P. ovata showed distinct water-use strategies that were dependent on host phenology. For P. ovata parasitizing the deciduous host, water use efficiency (WUE; ratio of photosynthetic rate to transpirational water loss) was 2-fold lower in the dry season than in the wet season; in contrast, WUE was maintained at the same level during the wet and dry seasons in P. ovata parasitizing the evergreen host. Generally, mistletoe and host diurnal cycles of stomatal conductance were linked, although there were clear differences in leaf water potential, with mistletoe showing anisohydric behaviour and the host showing isohydric behaviour. Compared to mistletoes attached to evergreen hosts, those parasitizing deciduous hosts had a 1.4-fold lower stomatal density and 1.2-fold wider stomata on both leaf surfaces, suggesting that the latter suffered less intense drought stress. This is the first study to show morphophysiological differences in the same mistletoe species parasitizing hosts of different phenological groups. Our results provide evidence that phenotypical plasticity (anatomical and physiological) might be essential to favour the use of a greater range of hosts.

PYRENE MORPHOLOGY OF THREE SPECIES OF Byrsonima Rich. ex Kunth (Malpighiaceae)1

ABSTRACT The species of the genus Byrsonima Rich. ex Kunth are of great medicinal and economic importance, but they are still poorly studied with respect to their propagules. This study describes, illustrates and comparse morphological aspects of the pyrenes of Byrsonima crassifolia (L.) Kunth, Byrsonima verbascifolia (L.) DC. and Byrsonima coccolobifolia Kunth occurring in areas of savannah of Boa Vista, Roraima. The pyrenes are globoid, obovoid to ovoid, with endocarp dark brown in color, with a corrugated and reticulate surface and corneous consistency. They possess distinctly septate locules with or without seeds, the outer wall of which are dark brown in color with corneous consistency and thin black inner walls also with corneous consistency. The number of locules and seeds per pyrene among the species varies. The seeds are exalbuminous, globoid, obovoid to ovoid, with a thin, smooth integument and are light-brown in color. They have radicular lobes and hypostasis. The embryo is continuous and axial with cylindrical spirally rolled cotyledons. The diameter of pyrenes of Byrsonima crassifolia is greater than in the other two species. The pyrenes of B. coccolobifolia are longer and heavier, while those of B. verbascifolia are lighter and the seeds have greater lengths, widths and thickness compared to the other two species studied. The three species have similar morphologies, differing in the size and weight of pyrenes and seeds.

Cell Viability, Mitotic Index and Callus Morphology of Byrsonima verbascifolia (Malpighiaceae)

The combined analysis of cell viability, mitotic index and callus morphology of species of commercial interest may favor the identification of cell masses with embryogenic characteristics at early stages of cultivation, allowing the development or improvement of protocols for in vitro plant regeneration through indirect embryogenesis. Byrsonima verbascifolia L. (DC.) (Malpighiaceae) is a Brazilian medicinal species native to the Cerrado, which has a low seed germination rate due to tegument dormancy. This study aimed to identify cells with embryogenic characteristics during growth of callus of B. verbascifolia, by assessing cell viability, mitotic index and cell morphology. Callus was induced from leaf explants and inoculated on MS medium with 4.52 μM 2,4-D and 4.44 μM benzylaminopurine (BAP). Friable calli were obtained at four distinct growth phases: lag (until the 30th), exponential (from 31st to the 70th day), linear (from 71st to the 100th day) and decline (from 101st to the 120th day). Calli with 20 and 30 days showed cells with embryogenic characteristics, that is, isodiametric shape, juxtaposed, with small vacuoles, thin cell wall and presence of amyloplasts. After 120 days, calli were mostly elongated cells with lower cell viability and mitotic index.