Shading minimizes the effects of water deficit in Campomanesia xanthocarpa (Mart) O Berg seedlings / Sombreamento minimiza o efeito do déficit hídrico em mudas de Campomanesia xanthocarpa (Mart) O Berg

The objective of this study was to evaluate the activity of antioxidant enzymes, the functioning of the photosystem II and quality of C. xanthocarpa seedlings cultivated under intermittent water deficit and shading levels and the influence of shading on recovery potential after suspension of the stress conditions. The seedlings were subjected to three levels of shading (0, 30, and 70%), six periods of evaluation (start: 0 days; 1st and 2nd photosynthesis zero: 1st and 2nd P0; 1st and 2nd recovery: 1stand 2nd REC; and END), and two forms of irrigation (control: periodically irrigated to maintain 70% substrate water retention capacity, and intermittent irrigation: suspension of irrigation). The plants subjected to intermittent irrigation conditions at 0% shading showed a reduction in water potential (Ψw) and potential quantum efficiency of photosystem II (Fv/Fm) and maximum efficiency of the photochemical process (Fv/F0) and an increase in basal quantum production of the non-photochemical processes (F0/Fm). Superoxide dismutase (SOD) activity was higher in the leaves than in the roots. The C. xanthocarpa is a species sensitive to water deficit but presents strategies to adapt to an environment under temporary water restriction, which are more temporary are most efficient under shading. The seedlings with water deficit at all levels of shading exhibited higher protective antioxidant activity and lower quality at 0% shading. The shading minimizes prevents permanent damage to the photosystem II and after the re-irrigation, the evaluated characteristics showed recovery with respect to the control group, except POD and SOD activities in the leaves.

O objetivo deste estudo foi avaliar a atividade de enzimas antioxidantes, o funcionamento do fotossistema II e a qualidade de mudas de C. xanthocarpa cultivadas sob déficit hídrico intermitente e níveis de sombreamento e a influência do sombreamento sobre o potencial de recuperação após suspensão das condições de estresse. As mudas foram submetidas a três níveis de sombreamento (0, 30 e 70%), seis períodos de avaliação (início: 0 dias; 1ª e 2ª fotossíntese zero: 1ª e 2ª P0; 1ª e 2ª recuperação: 1ª e 2ª REC; e final), e duas formas de irrigação (controle: periodicamente irrigado para manter 70% da capacidade de retenção de água do substrato, e irrigação intermitente: suspensão da irrigação). As plantas submetidas às condições de irrigação intermitente a 0% de sombreamento apresentaram redução do potencial hídrico (Ψw) e eficiência quântica potencial do fotossistema II (Fv/Fm) e máxima eficiência do processo fotoquímico (Fv/F0) e aumento da produção quantica basal dos processos não fotoquímicos (F0/Fm). A atividade da superóxido dismutase (SOD) foi maior nas folhas do que nas raízes. C. xanthocarpa é uma espécie sensível ao déficit hídrico, mas apresenta estratégias para se adaptar a um ambiente com restrição hídrica temporária, sendo mais eficientes sob sombreamento. As mudas com déficit hídrico em todos os níveis de sombreamento exibiram maior atividade antioxidante protetora e menor qualidade no sombreamento 0%. O sombreamento minimiza danos permanentes ao fotossistema II e após a re-irrigação, as características avaliadas apresentaram recuperação em relação ao grupo controle, exceto atividades de POD e SOD nas folhas.

Floral and reproductive biology and pollinators of Campomanesia guazumifolia (Cambess.) O. Berg., neglected species

Studies on the Myrtaceae family are mainly distributed in floristic surveys, reproductive studies of plant communities or related to family taxonomy. Based on this, the objective of the present study was to elucidate aspects of floral and reproductive biology and, of floral visitors from Campomanesia guazumifolia (Cambess.) O. Berg., a neglected species. Information was obtained on floral morphology and morphometry, anthesis, nectary, and structures attractive to pollinators, characterization of pollinators, receptiveness of stigma and maturing of the androecium components, and characterization of the reproductive system. Sete-capote tree has hermaphrodite flowers, and the floral opening occurs mainly during the daytime. Pollen grains was the main resource offered to pollinators. The flowers had mellow sweet odor, attracting mainly native bees and Apis melifera, which was characterized as effective pollinators. The species presents high reproductive efficiency and could be considered self-compatible; however, fertilization also occurs by cross-pollination.

Embryogenic potential of the callus of gabirobeira, Campomanesia adamantium(Cambess) O. Berg

Campomanesia adamantiumis a native plant species of Brazilian Cerrado with diverse economic potential and great medicinal importance. Its sexual propagation is impaired by the recalcitrance of its seeds, which prevents effective and profitable propagation. With the purpose of establishing commercial crops and minimizing the extractive use of vegetal resources, the aim of the present study was to induce embryogenic calli in nodal segments of gabirobeira, and to determine and characterize their embryogenic phase through the establishment of a growth curve based on cellular characteristics. Calli were induced using nodal segments inoculated in WPM culture medium without the addition of hormones (control) and with different concentrations of 2,4-D, IAA, IBA, NAA or picloram. Cytochemical and SEM analyses revealed cellular characteristics of the formation of meristematic centers that indicated 4.14 μM of picloram to be the best treatment for induction of embryogenic calli, and demonstrating their embryogenic potential. The treatment was used to establish a callus growth curve, from which it was inferred that calli should be transferred to new culture media on the 28thday to maintain cell viability.

Crescimento inicial de Campomanesia xanthocarpa O. Berg sob diferentes composições de substratos / Initial growth of Campomanesia xanthocarpa O. Berg under different substrate compositions

RESUMO: O objetivo do trabalho foi avaliar a influência de diferentes composições de substratos no crescimento inicial de Campomanesia xanthocarpa, bem como avaliar índices fisiológicos. O trabalho foi desenvolvido em Dourados-MS, no período de janeiro a outubro de 2008. Foi estudada a Campomanesia xanthocarpa sob cinco diferentes substratos (LVd/A/O= Latossolo Vermelho distroférrico+areia grossa lavada+Organosuper® (5:4:1 v/v); LVd/A/C= Latossolo Vermelho distroférrico+areia grossa lavada+cama-de-frango (5:4:1 v/v); LVd/A/O2= Latossolo Vermelho distroférrico+areia grossa lavada+Organosuper® (7:2:1 v/v); LVd/A/C2= Latossolo Vermelho distroférrico+areia grossa lavada+cama-de-frango (7:2:1 v/v); LVd/A= Latossolo Vermelho distroférrico+areia grossa lavada (6:4 v/v)), em vasos de 7 dm3, e mantidos em ambiente protegido com 100% de luminosidade. O substrato composto por Latossolo Vermelho distroférrico + areia grossa lavada proporcionou maior diâmetro de caule (8,29 mm), massa seca de raiz, caule e folhas (6,98; 4,49 e 9,06 g/planta, respectivamente) e aumento nos índices fisiológicos nas avaliações finais, indicando que este substrato pode ser utilizado no desenvolvimento de Campomanesia xanthocarpa.

ABSTRACT: The objective of this study was to evaluate the influence of different compositions of substrates on the initial growth of Campomanesia xanthocarpa and to evaluate the physiological rate. The study was conduct in the city of Dourados - state of Mato Grosso do Sul, Brazil, in the period from January to October 2008. The Campomanesia xanthocarpa was studying under five different substrates (LVd/A/O= Oxisol+coarse sand+Organosuper® (5:4:1 v/v); LVd/A/C= Oxisol+ coarse sand+ chicken manure (5:4:1 v/v); LVd/A/O2= Oxisol+ coarse sand+Organosuper® (7:2:1 v/v); LVd/A/C2= Oxisol+ coarse sand+chicken manure (7:2:1 v/v); LVd/A= Oxisol+ coarse sand (6:4 v/v)) in 7 dm3 pots and kept in a protected environment with 100% brightness. The substrate consisting of Oxisol + coarse sand provided greater stem diameter (8.29 mm), dry weight of the root, stem and leaf (6.98, 4.49 and 9.06 g / plant, respectively) and increased the physiological indices in the final evaluations, which indicates that this substrate can be used in the development of Campomanesia xanthocarpa.

Fructification phenology as an important tool in the recovery of iron mining areas in Minas Gerais, Brazil / Fenologia da frutificação como importante ferramenta na recuperação de áreas de mineração de ferro em Minas Gerais, Brasil

"Canga" is a name given to the ferruginous rocky fields that can be found in the "Quadrilátero Ferrífero" of Minas Gerais, Brazil. The endemism and species richness make them areas of special biological importance, regarded as high-priority for conservation. Nevertheless, they are being threatened by intense mining activity. Aiming to understand more about this flora, this study was performed in order to determine the maturation or dispersal period of the fruits of four Canga species, Alibertia vaccinioides K.Schum. (Rubiaceae), Coccoloba acrostichoides Cham. (Polygonaceae), Miconia sellowiana Naudin (Melastomataceae), and one probable new species of Calyptranthes Sw. (Myrtaceae). Although fruit maturation or dispersal tended to occur at the end of the dry season, some asynchrony was observed in these species, with food sources being available during most of the year. This shows that these species have the potential to attract animals the whole year round, and planting them for the recovery of iron mining areas may increase the community's self-regeneration capacity, leading to a more successful restoration process.

Canga é um nome dado para os campos rupestres ferruginosos encontrados no Quadrilátero Ferrífero de Minas Gerais. O endemismo e riqueza de espécies os tornam uma área de importância biológica especial, considerada prioritária para conservação. Além disso, tem sido submetida à intensa atividade mineradora. Este estudo objetivou determinar as épocas de maturação/dispersão de frutos de quatro espécies de ocorrência na canga, Alibertia vaccinioides K. Schum. (Rubiaceae), Coccoloba acrostichoides Cham. (Polygonaceae), Miconia sellowiana Naudin (Melastomataceae) e de uma provável espécie nova de Calyptranthes Sw. (Myrtaceae). Apesar da maturação/dispersão dos frutos ter apresentado uma tendência de ocorrer no final da estação seca, foi constatada uma assincronia do evento entre essas espécies, com disponibilidade de alimento aos animais frugívoros ao longo de grande parte do ano. O plantio dessas espécies para recuperação de áreas ferruginosas similares degradadas pela mineração poderá atrair fauna durante todas as estações, aumentando o potencial de autorregeneração da comunidade e o consequente sucesso no processo de restauração.

Impact of the invasive plant Syzigium jambos (Myrtaceae) on patterns of understory seedling abundance in a Tropical Premontane Forest, Costa Rica

Habitat fragmentation, along with other human-induced disturbances, increase the vulnerability of native habitats to be invaded by aggressive, ecologically released, exotic species. Syzigium jambos (L.) Alston (Myrtaceae, Rose Apple) is an important invader still spreading throughout Hawaii, the Antilles, Central and South America. This study examines the effects of S. jambos on plant understory diversity in a 25 ha Tropical Premontane Moist Forest in Atenas, Alajuela, Costa Rica, a protected watershed that supplies drinking water for several human communities. Our final objective is to develop a management strategy combining water protection with the preservation of a representative sample of the original plant diversity in the area. Thirty 2 x 2 m plots were distributed throughout the Municipal Forest maintaining a minimum of 10 m between plots, and 2 m from trails, to sample all understory seedlings and saplings of S. jambos, Coffea arabica (coffee) and tree seedlings. We found a clear dominance of S. jambos over all other understory plants. Of the total 1,285 sampled plants, S. jambos comprised 51%, coffee seedlings represented 14.78%, being the rest tree seedlings. Syzigium jambos had the highest density (5.46 plants/m2, S.D. = 6.44) compared to tree (3.67 plants/m2, S.D. = 3.44) and coffee seedlings (1.58 plants/m2, S.D. = 2.13). There was a highly significant negative relationship between the relative abundance of S. jambos and tree (r2 = 0.52, p < 0.00001) and coffee seedlings (r2 = 0.28, p < 0.002). The abundance of coffee seedlings did not affect the abundance of tree seedlings (r2 = 0.01, p < 0.58). Since the canopy of the Municipal Forest is relatively closed and composed of a monolayer of trees with almost no overlapping crowns, we found no relationship between canopy cover and the abundance of S. jambos. The height distribution indicated that the majority of S. jambos individuals were seedlings and saplings (height < or = 1.5 m)...

La fragmentación del hábitat, junto con otros disturbios antropogénicos, aumentan la vulnerabilidad de los ambientes nativos a la invasión por especies exóticas, agresivas y sin controles ecológicos. Syzigium jambos (L.) Alston (Myrtaceae, Manzana Rosa) es una invasora importante que todavía está extendiendose en Hawaii, Las Antillas, Centro y Suramérica. Este estudio examina los efectos de S. jambos sobre la diversidad de plantas del sotobosque en un Bosque Húmedo Premontano de 25 ha en Atenas, Alajuela, Costa Rica, una microcuenca protegida que suple de agua potable a varias comunidades. Nuestro objetivo final es desarrollar una estrategia de manejo que combine la protección del agua con la conservación de una muestra representativa de la diversidad de plantas original del área. Distribuimos 30 parcelas de 2 X 2 m en el Bosque Municipal manteniendo una distancia mínima de 10 m entre parcelas y 2 m lejos de los senderos, para muestrear las plántulas y brinzales de S. jambos, Coffea arabica (café) y árboles. Encontramos una clara dominancia de S. jambos sobre las demás plantas de sotobosque. De 1 285 plantas muestreadas S. jambos representó 51%, el café abarcó 14,78%, siendo el resto plántulas de árboles. Syzigium jambos tuvo la mayor densidad (5.46 plantas/m2, D.E. = 6.44) en comparación a plántulas de árboles (3.67 plantas/ m2, D.E. = 3.44) y de café (1.58 plantas/ m2, S.D. = 2.13). Hubo una relación negativa entre la abundancia relativa de S. jambos y las plántulas de árboles (r2 = 0.52, p < 0.00001) y café (r2 = 0.28, p < 0.002). La abundancia de las plántulas de café no afectó la abundancia de las plántulas de árboles (r2 = 0.01, p < 0.58). Ya que el dosel del Bosque Municipal es relativamente denso y se compone de una monocapa de árboles casi sin traslape entre copas, no encontramos relación entre la cobertura del dosel y la abundancia de S. jambos. La distribución de altura indicó que la mayoría de los individuos de S. jambos eran plántula...