© 1993 Heron Publishing—Victoria, Canada
Needle polyamine concentrations and potassium nutrition in Scots pine
Tytti Sarjala and Seppo Kaunisto
The Finnish Forest Research Institute, Parkano Research Station, SF-39700 Parkano, Finland / Received October 28, 1992
Summary
The response of free polyamines (putrescine, spermidine and spermine) in needles of Scots pine (Pinus sylvestris L.) to varying needle potassium concentrations was investigated in two potassium fertilization experiments on drained peatlands.
A significant negative correlation was observed between putrescine and potassium concentrations in needles. Putrescine responded
more sensitively to decreasing needle K concentrations during the growing season than during the winter. Putrescine accumulation
started when
needle potassium concentrations were above 5.5 mg gdw–1 in summer and above 5.0 mg gdw–1 in winter. A decrease in needle potassium concentrations below 4.3 mg gdw–1 in summer and below 3.5 mg gdw–1 in winter resulted in an exponential increase in putrescine concentrations. Putrescine accumulation was initiated well above
the needle potassium concentrations generally considered indicative of deficiency.
The exponential increase in putrescine concentrations in winter occurred within the range of needle potassium concentrations
that has been identified as indicating severe potassium deficiency.
Keywords:
Pinus sylvestris, potassium deficiency, putrescine, spermidine, spermine.
