Genetic control underlying the flowering-drought tolerance trade-off in the Antarctic plant Colobanthus quitensis.

Plants inhabiting environments with stressful conditions often exhibit a low number of flowers, which can be attributed to the energetic cost associated with reproduction. One of the most stressful environments for plants is the Antarctic continent, characterized by limited soil water availability and low temperatures. Induction of dehydrins like those from the COR gene family and auxin transcriptional response repressor genes (IAAs), which are involved in floral repression, has been described in response to water stress. Here, we investigated the relationship between the water deficit-induced stress response and the number of flowers in Colobanthus quitensis plants collected from populations along a latitudinal gradient. The expression levels of COR47 and IAA12 genes in response to water deficit were found to be associated with the number of flowers. The relationship was observed both in the field and growth chambers. Watering the plants in the growth chambers alleviated the stress and stimualted flowering, thereby eliminating the trade-off observed in the field. Our study provides a mechanistic understanding of the ecological constraints on plant reproduction along a water availability gradient. However, further experiments are needed to elucidate the primary role of water availability in regulating resource allocation to reproduction in plants inhibiting extreme environments.

Frequent fires alter tree architecture and impair reproduction of a common fire-tolerant savanna tree.

Several Cerrado tree species have traits and structures that protect from fires. The effectiveness of a trait depends on the fire regime, especially the frequency. We used Vochysia elliptica, a common Cerrado tree, as a model to test whether different fire frequencies alter crown architecture and flower, fruit and seed production. We analysed the effect of fire on the production of inflorescences, fruits and seeds, as well as seed germination and tree architecture of 20 trees in each of three plots of a long-term ecological experiment managed with different fire regimes: burned every 2 years (B), burned every 4 years (Q) in mid-dry season and an area protected from fire (C). We found a large negative effect of fire frequency on crown architecture and on flower and fruit production. Trees in C and Q had significantly more main branches and a larger crown area than trees in B. At its peak, a tree in C was expected to produce 2.4 times more inflorescences than Q, and 15.5 times more than B, with similar magnitudes for fruits. Sixty per cent of trees in B and 10% in Q produced no fruits. The differences in architecture might explain the reduction in sexual reproduction due to a smaller physical space to produce flowers at the branch apices. Resource limitation due to plant investment to replace burned vegetative parts may also decrease sexual reproduction. Our results indicate potentially severe consequences of high fire frequencies for population dynamics and species persistence in Cerrado communities.

Growth and reproduction respond differently to climate in three Neotropical tree species.

The response of tropical forests to anthropogenic climate change is critically important to future global carbon budgets, yet remains highly uncertain. Here, we investigate how precipitation, temperature, solar radiation and dry- and wet-season lengths are related to annual tree growth, flower production, and fruit production in three moist tropical forest tree species using long-term datasets from tree rings and litter traps in central Panama. We also evaluated how growth, flower, and fruit production were interrelated. We found that growth was positively correlated with wet-season precipitation in all three species: Jacaranda copaia (r = 0.63), Tetragastris panamensis (r = 0.39) and Trichilia tuberculata (r = 0.39). Flowering and fruiting in Jacaranda were negatively related to current-year dry-season rainfall and positively related to prior-year dry-season rainfall. Flowering in Tetragastris was negatively related to current-year annual mean temperature while Trichilia showed no significant relationships of reproduction with climate. Growth was significantly related to reproduction only in Tetragastris, where it was positively related to previous year fruiting. Our results suggest that tree growth in moist tropical forest tree species is generally reduced by drought events such as those associated with strong El Niño events. In contrast, interannual variation in reproduction is not generally associated with growth and has distinct and species-specific climate responses, with positive effects of El Niño events in some species. Understanding these contrasting climate effects on tree growth and reproduction is critical to predicting changes in tropical forest dynamics and species composition under climate change.

Flowering levels, harvest season and yields of cupuassu (Theobroma grandiflorum) / Níveis de floração, período de safra e produção do cupuaçuzeiro (Theobroma grandiflorum)

Cupuassu (Theobroma grandiflorum), a specie native to Amazonia, has been planted commercially in Brazil to satisfy the demand for the flavorful juice obtained from the pulp around its seeds. The trees are notorious for low and irregular fruit production. Data gathered over two seasons from trees in a germplasm collection in Pará, Brazil, showed that some of them fruited more regularly than others. Differences in fruit production correlated to differences in flower production. Tree-to-tree variation in flower production, fruit production, and consistency of both over time suggest considerable scope for improving yields by selection. Hand pollinations resulted in a much higher frequency of fruit set than open pollinations, indicating that lack of effective pollination is also a reason for low yield. However, attempts to increase the level of effective pollination are handicapped by low knowledge about the pollinators of cupuassu and their behavior.

Cupuaçu (Theobroma grandiflorum) é uma espécie nativa da Amazônia que vem sendo plantada comercialmente no Brasil para satisfazer a demanda pelo seu suco, de sabor marcante, obtido da polpa que envolve as suas sementes. As árvores não notórias pela sua baixa e irregular produtividade. Dados obtidos de dois períodos produtivos, de árvores de uma coleção de germoplasma no estado do Pará, Brasil, mostraram que algumas delas frutificam mais irregularmente que outras. Diferenças na produção de frutos foram correlacionadas à diferenças na produção de flores. Variações entre plantas nas produções de flores e de frutos, e a repetibilidade de ambos ao longo do tempo sugerem melhoria das colheitas por seleção. Polinizações manuais resultaram em aumento no pegamento dos frutos, indicando que a falta de polinizador efetivo é também um causa da produtividade baixa. Entretanto, tentativas para aumentar o nível de polinização efetiva são dificultadas pelo pouco conhecimento sobre os agentes polinizadores do cupuaçu e seu comportamento.

Flowering levels, harvest season and yields of cupuassu (Theobroma grandiflorum)

Cupuassu (Theobroma grandiflorum), a specie native to Amazonia, has been planted commercially in Brazil to satisfy the demand for the flavorful juice obtained from the pulp around its seeds. The trees are notorious for low and irregular fruit production. Data gathered over two seasons from trees in a germplasm collection in Pará, Brazil, showed that some of them fruited more regularly than others. Differences in fruit production correlated to differences in flower production. Tree-to-tree variation in flower production, fruit production, and consistency of both over time suggest considerable scope for improving yields by selection. Hand pollinations resulted in a much higher frequency of fruit set than open pollinations, indicating that lack of effective pollination is also a reason for low yield. However, attempts to increase the level of effective pollination are handicapped by low knowledge about the pollinators of cupuassu and their behavior.

Cupuaçu (Theobroma grandiflorum) é uma espécie nativa da Amazônia que vem sendo plantada comercialmente no Brasil para satisfazer a demanda pelo seu suco, de sabor marcante, obtido da polpa que envolve as suas sementes. As árvores não notórias pela sua baixa e irregular produtividade. Dados obtidos de dois períodos produtivos, de árvores de uma coleção de germoplasma no estado do Pará, Brasil, mostraram que algumas delas frutificam mais irregularmente que outras. Diferenças na produção de frutos foram correlacionadas à diferenças na produção de flores. Variações entre plantas nas produções de flores e de frutos, e a repetibilidade de ambos ao longo do tempo sugerem melhoria das colheitas por seleção. Polinizações manuais resultaram em aumento no pegamento dos frutos, indicando que a falta de polinizador efetivo é também um causa da produtividade baixa. Entretanto, tentativas para aumentar o nível de polinização efetiva são dificultadas pelo pouco conhecimento sobre os agentes polinizadores do cupuaçu e seu comportamento.

Produção de flores cortadas no estado de Minas Gerais / Production of cut flowers in the state o Minas Gerais

As flores de corte são importantes produtos da floricultura brasileira, as características da produção mineira são, no entanto, desconhecidas. Objetivou-se realizar um estudo da produção de flores de corte no estado de Minas Gerais, aplicou-se um questionário aos produtores do Estado , no período de 2003 a 2005. As visitas foram feitas in loco e os produtores foram identificados por meio de visitas nas áreas produtivas e os questionários foram respondidos por eles próprios. Analisando-se as respostas contidas nos questionários, identificou-se que a produção de flores de corte no estado de Minas Gerais é uma atividade realizada por 188 produtores, numa área plantada de aproximadamente 290,6836 ha As principais espécies cultivadas no Estado são: rosa (151,5710), sempre-vivas (57,26 ha), copo-de-leite (16,0255 ha), cravo (12,6290 ha) e helicônia (11,7600 ha). A produção é vendida para o todo o Brasil e também exportada para países da Europa, Ásia e América do Norte. Os principais produtos exportados são: rosas de corte, orquídeas de corte e sempre-vivas.

Cut flowers are important products of Brazilian floriculture. The characteristics of Minas Gerais production are, nevertheless, unknown. So, with the purpose of performing a study of the cut flower production in the state of Minas Gerais, a questionnaire was applied to flower growers of Minas Gerais state, in the period of 2003 to 2005. The visits were paid in loco and the growers were identified by means of visits to the flower-growing areas and the questionnaires were answered by them. By analyzing the answers contained in the questionnaires, it was identified that the cut flower production in the state of Minas Gerais is a business accomplished by 188 growers in a planted area of about 290.6836 ha. The main species grown in the state are: rose (151.5710 ha), sempre-vivas (57.26 ha), cala lilly flowers (16.0255 ha), carnation (12.6290 ha) and heliconia (11.7600 ha). The production is sold all over Brazil and it is also exported to countries of Europe, Asia and North America. The main exported produces are: cut roses, cut orchids and sempre-vivas.

Comunicação de riscos relacionada a agrotóxicos no Pólo floricultor de Nova Friburgo, RJ / Risk communication related to pesticides in the Hub florist Nova Friburgo, RJ

O uso intensivo de agrotóxicos nas lavouras desacompanhado de políticas normativas e de controle resulta numa série de impactos sobre a saúde humana e sobre o meio ambiente. As intoxicações sofridas pelos trabalhadores rurais podem estar atreladas a vários fatores como, por exemplo, a dificuldade de compreensão das informações sobre os agrotóxicos. Uma solução seria uma assistência técnica mais eficaz e dissociada das casas comerciais, fato cada vez mais presente, acarretando o aumento no consumo desses produtos. Em alguns casos, o acesso às informações fica restrito somente à leitura de bulas e rótulos dos produtos utilizados, sendo a única fonte de comunicação de riscos existente. É um dado preocupante, já que é reconhecido o baixo nível de escolaridade dos agricultores. O presente estudo tem como objetivo analisar o processo de comunicação de riscos relacionado aos agrotóxicos no trabalho rural do Pólo Floricultor de Nova Friburgo/RJ, através de um estudo de recepção de informações, por parte de agricultores, referente aos rótulos e bulas dos principais agrotóxicos utilizados por eles durante o seu processo de trabalho. Através de uma abordagem qualitativa, foram aplicados questionários semi-estruturados a 29 dos 30 produtores de flores locais, avaliando o seu processo de trabalho, seus anseios e o conhecimento acerca das questões que envolvem o uso dos agrotóxicos. A análise dos dados identificou uma série de situações relacionadas com o nível de informações e a sua interpretação pelos trabalhadores; o manejo indevido atribuído ao desconhecimento dos reais riscos que estão expostos é uma delas...

The intensive use of pesticides for crop protection results in impacts on human and environmental health status, particularly when this use is not associated with normative policies and control actions. Major rural workers poisonings can be straight associatedto a number of factors, including difficulties to comprehend the available information. One of many solutions should be a more effective and independent technical assistance,dissociated with commercial interests – a serious situation usually more seen and that can be pointed as one of the main determinants of pesticides use increase in the last few years. In some cases, information access is restricted to labels reading, constituting the only information resource available for a large group of rural workers. This situation is even more serious considering these professionals’ low formal-educational background. The present study aims to analyze pesticides risk communication process in a rural,flower-producer community of Nova Friburgo municipality, Rio de Janeiro State – Brazil, through an information-reception study focusing labels reading. Through a qualitative health research approach, semi-structured questionnaires were applied to 29of the 30 local flower producers aiming to characterize local work processes, workers beliefs and perceptions, as well as to identify their ability to correctly understand pesticides labels information (visual and written). Results showed that this information is not correctly understood by workers, leading to some unsafe work practices such asinappropriate pesticides formulation and use and several exposures situations, as well as the non-adoption of protective gear. These data point the need of a more effective risk communication policy, particularly involving the community...