Germination of pretreated Scots pine seeds after long-term storage

Abstract

Improvement of seed quality by pretreatments is indispensable in current mechanized plant production. Pretreated seeds are usually sown immediately, but in some cases they also have to be stored. The aim of our work was to study the changes in germination indices of pretreated Scots pine (Pinus sylvestris L.) seeds and the impact of the incubation temperature on germination after long-term storage. Pretreated and nontreated Scots pine seeds of three forest stands and a seed orchard were stored for about 10 years at the temperatures of 2°C and –18°C. The changes in germination indices were studied using germination tests and radiography. The germination indices of both pretreated and nontreated seeds were impaired during long-term storage. In general the changes were greater in cold than in frozen storage. Decline of the germination indices was more obvious in pretreated seed orchard than in forest stand seeds. The germination indices of forest stand seeds, whether pretreated or not, was preserved equally well in cold storage, while in orchard seeds germination indices prevailed better in nontreated seed batches. Forest stand seeds incubated at 10°C maintained their germination indices better than seeds incubated at 5°C, while in orchard seeds the effect was not as obvious.