Differential Water Tolerance and Ethanol Accumulation in Prunus Species under Flooded Conditions

The effect of waterlogging on ethanol accumulation in the stems and roots of water sensitive and tolerant species of Prunus was examined. No or little accumulation of ethanol was found in the fine roots, but a close correlation was apparent between ethanol accumulation in the tap roots and stems and the sensitivity to waterlogging. A rapid ethanol accumulation was found in peach (Prunus persica Batsch) and Japanese apricot (P. mume Sieb. et Zucc.), while a slight accumulation in Japanese plum (P. salicina Lindl.) and little in P. japonica Thunb.Peach trees grafted on P. japonica rootstocks showed the greater tolerance and much less ethanol accumulation in the roots and stems than those on peach rootstocks.A soil drench of aqueous ethanol at concentrations of 2, 7 and 20% reduced the shoot growth of young peach and P. japonica seedlings. P. japonica showed a slightly greater tolerance to 7% ethanol application, but no marked difference in the injury symptoms was observed between the two species.