On the water absorption by Pinus koraiensis seeds

Abstract

The process of water absorption by Pinus koraiensis seeds was studied with a view of clarifying the causes for their delayed germination. It can be divided into the following three phases:
(1) Quick increase during a few days after bedding,
(2) Slow or nearly no increase, and
(3) Second quick increase, nearly equal in amount to that in (1). A movement from the second phase to the third one can be hastened by some pretreatments.
The depth of dormancy in these seeds seems to be very different from each other, and is apparent as a difference in the period of the second phase. In most seeds this second phase seems to extend over several or more months. More than half of these seeds complete germination in about two weeks without their testas, which is remarkable in the seeds without both testas and inner coats. Such seeds have non-dormant embryos, and the water absorption by them in the third phase is inhibited mainly by their testas.