DRY-MATTER PARTITIONING DURING THE PROPAGATION OF HIPPEASTRUM-HYBRIDUM AS AFFECTED BY LIGHT

Dry matter partitioning was investigated in bulbils propagated from tw in-scales and in 1-year-old bulbs of Hippeastrum hybridum (cv. Apple B lossom) under different light regimes. Irrespective of the light regim es imposed there was a steady decrease in the dry weight and starch of the scales used for bulbis propagation. The dry weight and leaf area of bulbils propagated in continuous darkness were lower than of those of continuous light and dark-light treatments. When dark-grown bulbils were transferred to the light (dark-light treatment) their leaves gre ened rapidly and expanded to the size of those grown in continuous lig ht. In the initial phase of development, bulbs of plants from 1-year-o ld bulbs functioned as an efficient source of assimilates for shoot an d root growth. Starch reserves and sucrose were mobilized for the grow th of roots and leaves. This flux was reversed when the plants reached the 50th day after planting in full light, and the 75th day after pla nting in 50% light, indicating that the bulbs changed from being sourc es to sinks.