The effect of the symbiosis between arbuscular mycorrhizal fungi (AMF) and plants of yellow passion fruit, submitted to water stress during seven days, 40 days after the inoculation, was studied in an experiment using a completely randomized design, with factorial arrangement and the following treatments: (a) with and without water stress; (b) inoculation with Gigaspora albida, Gigaspora margarita or Glomus etunicatum and uninoculated control; (c) two inoculum levels: 200 and 400 spores/plant, with four replicates. The soil was a Red Yellow Podzol (3 mg of P/dm³). Measurements of diffusive resistance, transpiration and leaf temperature were taken from four leaves of each treatment, and the growth was evaluated by height, leaf area and total dry biomass. Data were analized by the NTIA statistic program. Development of inoculated plants was not affected by the stress while uninoculated plants did not grow under any condition. Non mycorrhizal seedlings did not show wilt symptoms, probably due to their small size. In general, seedlings associated to AMF and submitted to stress showed higher values of diffusive resistance and leaf temperature and lower transpiration rates than those not stressed. Among the inoculated seedlings, those associated with G. etunicatum presented lower diffusive resistance and higher transpiration only when compared with G. albida. In general, mycorrhization was beneficial to passion fruit seedlings, increasing growth even under water stress.
plant growth; transpiration; diffusive resistance; leaf temperature; mycorrhiza
