Phosphorus reduces salinity stress in micropropated potato

The present study was conducted to determine whether varying the sodium chloride (NaCl) concentrations in Murashige and Skoog (MS) basal medium could affect radiophosphorus (³²P) uptake, and whether high NaCl stress was moderated by the availability of inorganic phosphorus (Pi) to micropropagated potato (Solanum tuberosum L. cv. Russet Burbank). The kinetics of³²P uptake in micropropagated potato plantlets was studied over a 48-hr interval in MS medium containing 1.25 mM Pi and varying concentrations of NaCl (0 to 120 mM). The³²P activity of the top-most trifoliate leaf increased considerably with time, but decreased significantly as medium NaCl concentrations increased. The³²P activity of the root tips at 48 hr was greater, but translocation of Pi into leaves was less, as medium NaCl concentration increased. As medium Pi concentration was increased from 0 to 2.5 mM, in the presence of 120 mM NaCl,³²P activity decreased in root tips but translocation into the topmost leaves occurred more efficiently.