SALINITY AND PHYSIOLOGY OF PASSIFLORA EDULIS
Passiflora edulis plants were grown in sand culture and subjected to salinity to determine its influence on physiological characteristics. Solution was made by adding addition of sea salt to half-Hoaglands solution with an increase in 1 dS/m every other day until 4 dS/m was reached. Control plants received half-Hoaglands solution, and three separate studies were conducted. Measurements were made after six weeks of treatment. Sodium accumulation in leaves was less than that of chloride accumulation. Whole plant root conductance was reduced by salinity, but this response was mediated by reduced root growth. Hydraulic conductivity of roots did not differ between control and treated plants when standardized to a unit dry weight or area basis. Xylem potential was reduced by salinity to a greater relative degree during pre-dawn than during midday. Maximum net photosynthesis and light use efficiency were reduced more by salinity than was CO2 use efficiency. Chlorophyll fluorescence indicated the stress the plants experienced during daily sunlight exposure was not permanent, as maximum quantum efficiency recovered during the nocturnal period. Salinity did not influence dark respiration of leaves or osmotic potential of roots and leaves. Results indicate the purple passion fruit may rank as moderately sensitive to salinity stress.
Marler, T.E. (2013). SALINITY AND PHYSIOLOGY OF PASSIFLORA EDULIS. Acta Hortic. 975, 293-298
gas exchange, hydraulic conductivity, passion fruit, salinity, xylem potential