ABSTRACT
Germination and post-seminal development are important stages for the establishment of plants and for determining their tolerance to diesel oil. Diesel-tolerant species can contribute to the recovery of contaminated areas, and leguminous plants are promising in the treatment of contaminated soil through nitrogen fixation. This study identified the effects of diesel oil-contaminated soil on the germination and seedlings of the leguminous species Mimosa bimucronata, M. flocculosa, and M. scabrella var. aspericarpa. The experiment comprised two treatments contaminated (4% concentration) and uncontaminated soil and was performed in a greenhouse for 90 days, with evaluations 30, 60, and 90 days after sowing. Germination was not affected, but most root and aerial system parameters were statistically lower in contaminated soil, indicating low initial development potential in soil contaminated with diesel oil. Moreover, the negative effects increased with higher exposure time to the contaminant.
Subject(s)
Fabaceae , Mimosa , Soil Pollutants , Biodegradation, Environmental , Germination , Soil , Soil Pollutants/toxicity , Soil Pollutants/analysisABSTRACT
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 percent 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.
ABSTRACT
The vascular system in the rhizome of ginger (Zingiber officinale R.) is arranged in three distinct systems: an inner system that form the principal vascular system of the rhizome, an intermediated system originating a thin camada of anastomosing vascular strands, having direct contact with the inner system and an outer system free of the anastomosis with the another vascular systems. The intermediated and inner system are associated with the root insertion and whole systems are relacioned with the formation of bud adventicious maintaing the same pattern of the rhizome and the communication between the outer and inner system occurs through the bridging to inner system leaf traces.
