The effect of soil polluted by diesel oil on the germination of seeds and the growth of Schinus terebinthifolius Raddi seedlings was analyzed at different times after contamination of the soil. The experiments were conducted under greenhouse conditions, with four treatments and five repetitions. The four treatments included: soil contaminated 30 (T30), 90 (T90) or 180 (T180) days before planting as well as a non-polluted soil (T0) (control). Soil saturated to 50% of its maximum retention capacity (MRC) was contaminated with diesel oil at a rate of 92.4 mL per kg. The germination rate and germination speed index (GSI) were significantly affected only in T30. The development of the plants was affected significantly in all the treatments, with reductions of biomass and eophyll area. It could be concluded that diesel oil significantly affected the germination, GSI and seedling growth of S. terebinthifolius, but the toxic effect decreased over the time.

Visando contribuir para o conhecimento das respostas morfoanatômicas de espécies arbóreas à hipoxia, efeitos do alagamento em órgãos vegetativos de Aegiphila sellowiana foram estudados. Indivíduos jovens foram mantidos em substrato drenado e alagado por 50 e 80 dias. Houve mortalidade de 40% das plantas alagadas. As sobreviventes produziram fissuras peridérmicas na base do hipocótilo, raízes diageotrópicas e lenticelas hipertrofiadas em hipocótilos e raízes. Em plantas alagadas: (1) as raízes secundárias apresentaram maior diâmetro, córtex mais espesso, células corticais maiores, espaços intercelulares maiores, cilindro vascular e elementos de vaso menores; (2) as raízes primárias em estrutura secundária e hipocótilos apresentaram súber e feloderme mais espessos; (3) as folhas apresentaram nervura mediana e mesofilo mais espesso, tricomas mais abundantes e estômatos menores. Constatou-se que A. sellowiana é intolerante ao alagamento do solo, fato evidenciado pela morte de parte das plantas. Entretanto, as sobreviventes apresentaram modificações morfoanatômicas que conferem tolerância. Sugere-se que a capacidade diferencial de tolerância apresentada entre os indivíduos pode ser resultado da presença de diferentes genótipos dentro do conjunto de plantas utilizado neste estudo.

In order to uncover the morpho-anatomical responses of tree species to hypoxia, we studied the effects of flooding on vegetative organs of Aegiphila sellowiana. Young individuals were kept in drained and flooded soil for 50 and 80 days. Under flooding, there was a mortality rate of 40%. The surviving plants produced peridermic fissures, superficial roots and hypertrophied lenticels. Secondary roots of flooded plants presented greater diameter, thicker cortex, greater diameter of the cortical cells, larger intercellular spaces, and thinner vessel elements and vascular tissues. In the main roots under secondary growth and hypocotyls, cork and phelloderm became thicker under flooding. Leaves of flooded plants presented thicker midrib, larger mesophyll, higher number of trichomes and smaller stomata. Considering that part of the plants subject to flooding have died, it is possible to suggest that A. sellowiana is intolerant of soil inundation. However, the surviving plants showed morpho-anatomical modifications that could have conferred some tolerance to them. Thus, the differential tolerance observed among individuals of A. sellowiana indicates a variability of genotypes in the samples used in this study.