We studied the germination of Baccharis dracunculifolia (Asteraceae), achene, a species that has colonizing traits, which makes it a potential candidate for forest rehabilitation. Achenes were collected in 1998 and were germinated at 15º, 20º, 25º and 30ºC under continuous light, and darkness conditions with four replicates with 25 achenes in each. We had also collected achenes in 1997, ând they were germinated at 20º and 25ºC, under the same conditions. The mean germination rate and emergency velocity index (EVI) were calculated to answer the following questions: (a) How does the germination behavior of B. dracunculifolia's achenes vary under different temperature and light conditions? (b) Is there any relationship between the total number of germinated achenes and the EVI? (c) How does achene storage affect the germination rate? Achenes that germinated at 15ºC both under light and dark conditions and at 20ºC under light achieved significantly higher germination rates than achenes that germinated in the other treatments (p < 0.05). Achenes of B. dracunculifolia showed a positive relationship between EVI and germination rates (y = 0.0802x - 0.0386, r² = 0.91, p < 0.05). Higher EVI's were found among achenes that germinated at 15º and 20ºC under light and 15ºC under dark treatments. Storage only affected the germination rates at 20ºC under light condition (p < 0.05).
Baccharis dracunculifolia; germination; light and temperature conditions
