Potencial fisiológico de sementes de brássicas com ênfase no teste de envelhecimento acelerado Physiological potential of Brassica seeds with emphasis to the accelerated aging test

O presente trabalho comparou diferentes testes para a avaliação do potencial fisiológico de sementes de brássicas, com ênfase no teste de envelhecimento acelerado (TEA). Foram utilizados quatro lotes de sementes de repolho, cultivar Coração de Boi, quatro de sementes de couve-brócolis, cultivar Piracicaba Precoce, e cinco de sementes de couve, cultivar Georgia. Foram realizados os testes de germinação, primeira contagem de germinação, emergência de plântulas, condutividade elétrica e envelhecimento acelerado. Neste, foram empregados três procedimentos: tradicional (água), solução saturada (40 g 100 mL-1) e solução diluída (11 g 100 mL-1) de NaCl, a 42°C, por períodos de 48, 72 e 96 horas. Foi utilizado o delineamento inteiramente casualizado, com quatro repetições e análises isoladas para cada teste. Os testes de primeira contagem de germinação e velocidade de emergência de plântulas apresentaram potencial para avaliação do potencial fisiológico de sementes de repolho e couve-brócolis. Já para sementes de couve, os testes de emergência de plântulas e condutividade elétrica foram os mais eficientes. TEA também foi eficiente na avaliação do potencial fisiológico de sementes de brássicas. Para repolho, a melhor distinção entre o potencial fisiológico das sementes através do TEA aconteceu seguindo o procedimento tradicional e empregando solução diluída de NaCl, ambos por 48 e 72 horas, e solução saturada de NaCl por 72 e 96 horas. Para couve-brócolis, todas as variações do TEA testadas foram eficientes na identificação dos lotes de semente de qualidade superior. Já para couve, os melhores resultados foram obtidos aplicando TEA na metodologia tradicional por 96 horas e solução diluída por 72 horas. Observou-se ainda que, em comparação com o uso de água, a utilização de solução salina no TEA inibiu sensivelmente o crescimento e desenvolvimento de fungos.<br>The present work compared different tests for the evaluation of the physiological potential of Brassica seeds with emphasis to the accelerated aging test (AAT). Four lots of cabbage seeds cv. Coração de Boi, four lots of broccoli seeds cv. Piracicaba Precoce and five lots of collard seeds cv. Georgia were used. Tests of germination, first germination counting, seedling emergence, electrical conductivity and accelerated aging were accomplished. In this test three procedures were used: traditional (water), saturated NaCl solution (40 g/100 mL) and diluted NaCl solution (11 g/100 mL), at 42°C for 48, 72 and 96 hours. The experiment followed a completely randomized design with four replicates and individual evaluations for each test. The tests of first germination counting and speed of seedling emergence presented potential for evaluation of the physiological potential of cabbage and broccoli seeds. For collard seeds, the tests of seedling emergence and electrical conductivity were the most efficient. The AAT was also efficient in the evaluation of the physiological potential of Brassica seeds. For cabbage, the best distinction among the physiological potential of the seeds through the AAT was obtained following the traditional procedure and with diluted NaCl solution, both for 48 and 72 hours, and with saturated NaCl solution for 72 and 96 hours. For broccoli seeds, all of tested AAT procedures were efficient in the identification of the seed lots of superior quality. For collard seeds, the best results were obtained with the AAT in the traditional methodology for 96 hours and with diluted NaCl solution for 72 hours. It was observed that, in comparison to the use of water, the use of saline solution in the AAT inhibited sensibly the fungi growth and development

Deforestation Impacts on Bat Functional Diversity in Tropical Landscapes

<div><p>Functional diversity is the variability in the functional roles carried out by species within ecosystems. Changes in the environment can affect this component of biodiversity and can, in turn, affect different processes, including some ecosystem services. This study aimed to determine the effect of forest loss on species richness, abundance and functional diversity of Neotropical bats. To this end, we identified six landscapes with increasing loss of forest cover in the Huasteca region of the state of Hidalgo, Mexico. We captured bats in each landscape using mist nets, and calculated functional diversity indices (functional richness and functional evenness) along with species richness and abundance. We analyzed these measures in terms of percent forest cover. We captured 906 bats (Phyllostomidae and Mormoopidae), including 10 genera and 12 species. Species richness, abundance and functional richness per night are positively related with forest cover. Generalized linear models show that species richness, abundance and functional richness per night are significantly related with forest cover, while seasonality had an effect on abundance and functional richness. Neither forest cover nor season had a significant effect on functional evenness. All these findings were consistent across three spatial scales (1, 3 and 5 km radius around sampling sites). The decrease in species, abundance and functional richness of bats with forest loss may have implications for the ecological processes they carry out such as seed dispersal, pollination and insect predation, among others.</p></div