Efeitos da sucessão florestal sobre a anurofauna (Amphibia: Anura) da Reserva Catuaba e seu entorno, Acre, Amazônia sul-ocidental Effect of the forest succession on the anurans (Amphibia: Anura) of the Reserve Catuaba and its periphery, Acre, southwestern Amazonia

O trabalho teve como objetivo verificar a abundância, riqueza e a composição da anurofauna em diferentes estágios sucessionais em uma floresta do Acre (10º04'S, 67º37'W) e seu entorno. Os dados foram obtidos entre agosto de 2005 a abril de 2006 em doze parcelas, localizadas em três áreas diferentes da floresta. Em cada área foram escolhidos quatro tipos de ambientes: floresta primária (mata), floresta secundária (capoeira), entorno (matriz) e floresta secundária (sucessão). Observou-se a presença de 27 espécies distribuídas em sete famílias. Maior abundância foi constatada na matriz dois e capoeira três, e a menor na sucessão um. A maior riqueza foi constatada na matriz dois, com o maior número de espécies exclusivas. A abundância de anuros correlacionou-se significativamente com a circunferência das árvores e lianas. A riqueza de anuros correlacionou-se marginalmente com a circunferência das árvores. A maior riqueza em ambientes de capoeiras e matriz pode ser explicada em grande parte pela existência nesses locais de poças d'água, maior heterogeneidade estrutural e poderem constituir estágios intermediários de perturbação. Esses estágios têm sido apontados como fatores que promovem e mantêm níveis elevados de biodiversidade. Ambientes com níveis intermediários de perturbação são importantes para a conservação da anurofauna.<br>The objective of this work it was verify the abundance, richness, and the anuran composition in plots of vegetation of different succession stages in a forest and the matrix that surrounds it, of Acre (10º04'S, 67º37'W). The sampling was carried out between August 2005 and April 2006 in twelve plots located in three different sites in the forest. In each site four kinds of environments were chosen: primary forest (wood), secondary forest (capoeira), periphery (matrix) and secondary forest (succession). A total of twenty-seven species distributed in seven families was found. Greater abundance was registered in the plots of matrix two and capoeira three and the least in succession one. The richness was greater in matrix two, with the greater number of exclusive species. The abundance of anurans correlated significantly, with the average circumference at the breast height of the trees of the plots. The richness however correlated only marginally, with this structural feature. The larger richness in plots of capoeira and matrix can be explained partially by the existence of temporary ponds and more structural heterogeneity is able constitute intermediary stages in a gradient of perturbation and this can increase the biodiversity. Thus environments with intermediary levels of disturbance are important for the conservation of the diversity of anuran amphibians

Biotechnology approaches to overcome biotic and abiotic stress constraints in legumes

Biotic and abiotic stresses cause significant yield losses in legumes and can significantly affect their productivity. Biotechnology tools such as marker-assisted breeding, tissue culture, in vitro mutagenesis and genetic transformation can contribute to solve or reduce some of these constraints. However, only limited success has been achieved so far. The emergence of “omic” technologies and the establishment of model legume plants such as Medicago truncatula and Lotus japonicus are promising strategies for understanding the molecular genetic basis of stress resistance, which is an important bottleneck for molecular breeding. Understanding the mechanisms that regulate the expression of stress-related genes is a fundamental issue in plant biology and will be necessary for the genetic improvement of legumes. In this review, we describe the current status of biotechnology approaches in relation to biotic and abiotic stresses in legumes and how these useful tools could be used to improve resistance to important constraints affecting legume crops.E. Prats is funded by an European Marie Curie Reintegration Grant, N. Rispail by (FP5) Eufaba project. Our work in this area is supported by Spanish CICYT project AGL-2002-03248 and European Union project FP6-2002-FOOD-1-506223. K. Singh’s work in this area is supported in part by the Grains Research and Development Corporation (GRDC) and the Department of Education, Science and Training (DEST) in Australia.Peer reviewe