EFFECT OF TEMPERATURE AND PHOTOPERIOD ON THE RAFFINOSE CONTENT OF SPRUCE ROOTS

The influence of temperature and photoperiod on raffinose synthesis in spruce roots (Picea abies (L.) Karst.) was investigated under control led environmental conditions in a phytotron. The raffinose content of the roots increased when the plants were subjected simultaneously to a change from long to short days and from summer-like day and night tem peratures to a climate which was more than 10-degrees-C colder. Only a very slight raffinose accumulation resulted from a change of daylengt h or temperature alone, but a subsequent additional change of temperat ure or daylength, respectively, caused an increase in the raffinose co ntent, yet only to half the amount found when both climate factors cha nged simultaneously. When the shoot was left under non-inducing condit ions, but the root was cooled, the raffinose content increased in the root, but not in the shoot. The root was also capable of inducing raff inose if the shoot was cut off after a few days of cold adaptation of the whole plant. For all climate changes the sucrose content changed m uch less than the raffinose content. Induction of raffinose was compar able in mycorrhizal and in non-mycorrhizal roots.