Physiological responses in passion fruit to drought stress and attempt to reduce the stress by cross-protection with heat treatment
Physiological responses in passion fruit to drought stress was investigated.
Plants, propagated by cutting, grown in pots were not irrigated for 12 days, and then irrigated for 9 days.
During the drought and re-irrigation treatments, photosynthetic rate (Pn), stomatal conductance (gs), maximum quantum efficiency of photosystem II (Fv/Fm), leaf water potential (Ψw), and vegetative growth were measured.
In addition, for testifying the effects of cross-protection using heat treatment on reducing drought stress, the plants immediately after rooting were subjected to heat treatment at 35, 45, and 55°C for 90 min.
And so, the experiment was conducted with a two-factor factorial design.
After 5-day drought treatment the stress was not severe, while after 12-day that was severe; soil water potentials were -10, -20, and -600 kPa after 3-, 5-, and 12-day drought treatment, respectively.
Interaction between drought and heat treatment was not significant for all data and heat treatment did not reduce drought stress.
At mild drought stress, gs decreased rapidly, while Pn decreased slowly; after 3- and 5-day drought treatment, gs decreased by 85 and 93% and Pn decreased by 55 and 84%. After 12-day, Pn was lower than limit of detection and gs decreased by 95%. By re-irrigation, Pn and gs were recovered.
After 5- and 12-day drought treatment, Ψw were -0.54 and
-0.67 MPa in drought treatment and -0.29 and -0.20 MPa in control.
The Ψw was not recovered fully by re-irrigation.
Fv/Fm was not decreased by drought stress.
Unexpanded and new leaves were not wilted by drought treatment while matured leaves were wilted, though after re-irrigation those were recovered.
There was no leaf fall during the experiment.
By drought treatment, vine extension and leaf formation were suppressed.
After re-irrigation, leaf in the drought treatment increased at the same rate as in the control, while vine extension was still suppressed slightly.
Kondo, T. and Koyama, A. (2023). Physiological responses in passion fruit to drought stress and attempt to reduce the stress by cross-protection with heat treatment. Acta Hortic. 1372, 51-56
DOI: 10.17660/ActaHortic.2023.1372.7
https://doi.org/10.17660/ActaHortic.2023.1372.7
DOI: 10.17660/ActaHortic.2023.1372.7
https://doi.org/10.17660/ActaHortic.2023.1372.7
leaf water potential, maximum quantum efficiency of photosystem II, photosynthetic rate, soil water potential, stomatal conductance, water stress
English
1372_7
51-56