Benefícios da suspensão de células vegetais para os fungos micorrízicos vesículo-arbusculares in vitro. II Efeitos da concentração e da viabilidade das células

The effects of addition of 0, 500, 1,000, 1,500, 3,000 and 6,000 of pueraria cell suspension per 20 ml of medium and cell viability on spore germination and germ tube growth of vesicular arbuscular mycorrhizal fungi were studied in agar and liquid media. Additions of 500 viable pueraria cells gave the greatest benefits to either germination or mycelial growth. On the other hand, addition of dead cells had no significant effects on the spores. This result indicates that the beneficial effects of plant cell suspension depend upon their metabolic activity. It was also found that the presence of viable plant cells did not stimulate independent growth of hyphae after detachment of the parent spore.Estudaram-se os efeitos da adição de 0,500, 1.000, 1.500, 3.000 e 6.000 células vegetais de puerária por 20 ml de meio e da viabilidade das mesmas sobre a germinação e crescimento micelial dos fungos micorrízicos vesículo-arbusculares em meio ágar-água e líquido. Os maiores benefícios, tanto para a germinação, quanto para crescimento micelial, foram obtidos com a adição de 500 células viáveis de puerária. A adição, ao meio, de células mortas não exerceu efeito significativo sobre os esporos, do que se infere que os benefícios das células vegetais sobre a germinação e crescimento micelial dependem da sua atividade metabólica. A presença de células viáveis não estimulou o crescimento independente do micélio destacado dos esporos

Beneficios da suspensão de células vegetais para os fungos micorrízicos vesículo-arbusculares in vitro. III Efeitos de diferentes meios de cultivo.

The effects of different culture medium of plant cells (B5, LS, MS, 5H and White) were evaluated in the presence or absence of Pueraria Pueraria phaseoloides (Roxb.) Benth cells upon germination and growth of mycelium of Scutellospora heterogama. Nondiluted MS medium extended the viability period of cells and at ten times (0,1X MS) dilution and addition of cells from Pueraria hypocotyls promoted the greatest benefit to germination and ramification of the mycelium of Gigaspora gigantea, Gigaspora margarita and Scutellospora heterogama. Despite the significant mycelium growth, colonization or sporulation by the VAM fungi in the culture medium containing plant cells were not observed.Avaliaram-se os efeitos de diferentes meios de cultivo de células vegetais (B5, LS, MS, SH, White) na presença e ausência de células de puerária Pueraria phaseoloides (Roxb) Benth sobre a germinação e crescimento micelial de Scutellospora heterogama. O meio MS não diluído prolongou o período de viabilidade das células, e quando diluído dez vezes (0,1 x MS), e com adição de células obtidas de hipocótilo de puerária promoveu os maiores benefícios para a germinação e ramificação do micélio de Gigaspora gigantea, Gigaspora margarita e Scutellospora hetero gama. Apesar do crescimento micelial abundante, em nenhum meio de cultivo com adição de células foram verificados sinais visuais de colonização das células ou esporulação dos fungos micorrízicos VA

Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)

Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R$^{2}$ = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R$^{2}$ = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution