EFFECT OF WATERLOGGING AND KINETIN ON THE STABILITY OF LEAF MEMBRANES, LEAF OSMOTIC POTENTIAL, SOLUBLE CARBON AND NITROGEN-COMPOUNDS AND CHLOROPHYLL CONTENT OF RICINUS PLANTS

Plants of castorbean (Ricinus communis L.) were waterlogged for 15 day s and were sprayed with 0, 10, 50 and -100 mgL(-1) of kinetin. The sta bility of leaf membranes was assessed by determining leakage of electr olytes from leaf discs exposed to heat (51 degrees C) and dehydration (40% PEG) stress. The membranes of waterlogged plants were more stable than control plants. Discs taken from waterlogged plants were less in jured by heat than by dehydration stress. The reverse was true in cont rol plants. Waterlogging increased proline and total free amino acids content but decreased leaf osmotic potential, chlorophyll, soluble sug ars, hydrolysable carbohydrates, soluble proteins and dry matter conte nt. Application of kinetin increased the stability of leaf membranes, chlorophyll, soluble sugars, soluble proteins and dry matter content. Statistical treatments of data show that waterlogging (WL), Kinetin (K ) and their interaction significantly affected the parameters tested. The only statistically non significant effect was waterlogging on tota l free amino acids content. The single factors (K and WL) and their in teraction (WL x K) have dual roles in their dominant and subsidiary ef fect (as indicated by eta(2) values). The results proved that kinetin can alleviate the effect of waterlogging on the parameters tested.