Effect of VA mycorrhiza on improving drought and chilling tolerance of bean plants (Phaseolus vulgaris L.)

Growth, productivity and water relations of Phaseolus vulgaris is L. var. F lexo were measured in responce to mycorrhizal inoculation with Glomus intra radices under both drought and chilling conditions and at different phospho rus levels. Experiments were conducted in a well controlled greenhouse and in a phytotrone at the research station of the Institute for Vegetable Scie nce at Durnast, Bavaria, Germany. Growth and yield of water-stressed plants were enhanced by mycorrhiza inoculation depending on the phosphorus level applied to plants. Chilling-stressed plants showed higher leaf water potent ial in responce to mycorrhizal inoculation. Electrolyte leakage of chilled- stressed plants showed no significant effect between mycorrhizal and non-my corrhizal plants. The results indicate that VA mycorrhiza improves water st atus during chilling stress and this effect was more pronounced under droug ht conditions. The effect of VA mycorrhiza at different P-levels on water r elations of bean plants under drought and chilling conditions and the effec ts on growth and yield after recovery from stress are discussed.