Temperature Relations of Germination in Acer platanoides L. Seeds

Abstract

The aim of this study was to describe the effect of temperature on the germination response of Acer platanoides L. seeds and the possible influence of dormancy. Moist chilled seeds (fruits) from eight trees were germinated at eight constant temperatures from 3 to 32C for 30 days. The highest germination was obtained at temperatures below 10C and the highest rate of germination was between 22 and 28C. The critical lower temperature for germination was estimated to be -2.6C, and the critical upper temperature between 30 and 35C. Temperatures above 10-15C increasingly inhibited the germination of seeds. Some of the non-germinated seeds were able to germinate after a second chilling period, possibly as a consequence of further release of primary dormancy and an indicated secondary dormancy. Seed survival decreased with increasing temperatures above 15C. The rate of germination was correlated with the accumulated thermal time at suboptimal temperatures. In conclusion, a constant temperature of 10C is recommended for testing the germination of seeds of A . platanoides.