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1.
An. acad. bras. ciênc ; 90(1): 59-71, Mar. 2018. tab, graf
Article Dans Anglais | LILACS | ID: biblio-886898

Résumé

ABSTRACT Varronia curassavica, a subshrubby medicinal species associated with restinga in the Atlantic Forest, has been exploited by local people and the pharmaceutical industry. Indeed, restingas have experienced a continuous process of degradation, and thus, with species and ecosystem both at risk, efforts to support conservation actions are required. The present study aimed to evaluate aspects of V. curassavica reproductive biology. To accomplish this, morphological characterization was performed by monitoring flowering events. The availability of nectar and pollen, as well as the frequency and behavior of floral visitors and dispersers, was also evaluated. This species exhibits both heterostyly and protogyny. Anthesis is diurnal, and flowers last less than a day. The high number of flower and fruit abortions suggests that mechanisms, such as self-incompatibility intra-morphs and easily detached flowers, contribute to reduced fruit production. The high diversity of floral visitors indicate a generalist pollination syndrome. Diptera, Hymenoptera and Lepidoptera were the main pollinators, and nectar was the main resource sought by these insects. Fruits were dispersed by birds and ants. It can be concluded that the interaction of V. curassavica with several species is a key factor in its own survival and for maintaining the biological diversity of restinga.


Sujets)
Boraginaceae/anatomie et histologie , Boraginaceae/physiologie , Fleurs/anatomie et histologie , Fleurs/physiologie , Plantes médicinales/physiologie , Valeurs de référence , Reproduction/physiologie , Spécificité d'espèce , Facteurs temps , Biodiversité , Pollinisation/physiologie , Dispersion des plantes
2.
Ciênc. cult. (Säo Paulo) ; 50(6): 408-16, Nov.-Dec. 1998.
Article Dans Anglais | LILACS | ID: lil-234531

Résumé

The emergence of biotechnologies and new plant breeding programs occurs in a contex of the green revolution based system. These programs could be based on the rational use of biodiversity and directed to sustainable agriculture. In Third World countries the system shows signs of exhaustion. Brazil is the country with the world's largest genetic diversity of plants, comprising over 55,000 identified species of an estimated total ranging from 350,000 to 550,000. The use of such biodiversity brings about the discussion on the interests of northern hemisphere countris - rich in financial resources and technology yet poor in genetic resources - and Southern Hemisphere countris - poor in financial resources and rechnology but very rich in biological diversity. In these countries the so-called appropriate biotechnologies may become "windows of opportunities" for the characterization, conservation and use of such diversity. It is urgent, however, that these countries create conditions and capacities to characterize, conserve and use their resources in the short term.


Sujets)
Agriculture , Biotechnologie , Écosystème , Brésil , Variation génétique
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