Experimental Agriculture · 2009 · 11 citations · 16 references
Life SciencesPlant BiologyPlant SciencesCrop PhysiologyPlant EcophysiologyPlant PhysiologyDroughtDrought PhysiologyDrought Stress PhysiologyDrought TolerancePlant Water UseStomatal PhysiologyDrought StressDrought Stress EffectsGreenhouse CultivationPlant Drought PhysiologyPlant Water-use EfficiencyStomatal ConductanceWater PotentialWater Stress Physiology
SUMMARY Abscisic acid (ABA) accumulation in leaves of drought-stressed coconut palms and its involvement with stomatal regulation of gas exchange during and after stress were investigated. Two Brazilian Green Dwarf coconut ecotypes from hot/humid and hot/dry environments were submitted to three consecutive drying/recovery cycles under greenhouse conditions. ABA accumulated in leaflets before significant changes in pre-dawn leaflet water potential (Ψ PD ) and did not recover completely in the two ecotypes after 8 days of rewatering. Stomatal conductance was influenced by ABA under mild drought and by Ψ PD under severe drought. There were no significant differences between the ecotypes for most variables measured. However, the ecotype from a hot/dry environment showed higher water use efficiency after repeated cycles of water stress.
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