EFFECT OF ROSE BENGAL AND LIGHT ON GROWTH OF BARLEY SEEDLINGS

Abstract

When barley seeds were allowed to germinate in the presence of rose bengal (a polyhalogenated fluorescein) and light, a reduction in shoot length, root length, and number of roots per plant was observed. Rose bengal also completely prevented the formation of root hairs in light and permitted the development of a minimal number of root hairs in the dark. Exposure of 48-hour-old, dark-grown seedlings to visible light resulted in a reduction in the total length of roots produced as compared with seedlings kept in the dark. When similar seedlings were exposed to the same intensity of light in the presence of rose bengal, greater reduction in the total length of roots was obtained. Production of root hairs was again inhibited by rose bengal in both light and dark. Some resumption of growth of rose bengal treated seedlings was obtained when the seedlings were washed after treatment and permitted to grow an additional period in the absence of rose bengal. This recovery was much less for seedlings which had been illuminated than it was for seedlings which developed in the dark.