Crescimento e partição de carboidratos em plantas de Sebastiania membranifolia submetidas ao alagamento

Abstract

The aim of this study was to evaluate the growth and carbohydrate partitioning in seedlings of Sebastiania membranifolia in response to flooding. Seedswere germinated in BOD type chamber at 25 ºC, on moistened germitest paper. Theseedlings were acclimatized for 20 days in a growth chamber and then transplanted intopolypropylene bags containing substrate consisting of sand , manure and soil (1:1:1), and transferred to a greenhouse protected with 50% shading for 40 days. At the end of this period three treatments were established: control (well watered), root flooded and completely flooded. The flooding was accomplished by placing the bags containing the plants individually in buckets with greater capacity. The evaluations were conducted at intervals of 12 days for a total period of 36 days, with four replicates for each treatment and evaluation period. The number of leaves, branches, stem height and dry weight of these parts, increased linearly in control plants over the period analyzed. For the flooded roots treatment, these parameters increased only until the 24th day, and in completely flooded plants, in general, this stress did not allow the growth of plants. The content of total soluble sugars, reducing sugars and starch were significantly lower in completely flooded plants, both in the leaves and in the roots. Root flooded plants had significant starch reduction in the roots, with values of the last measurement equal to those observed in completely flooded plants. These results suggest that S. membranifolia may be a promising species for revegetation of depleted areas subject to intermittent flooding.