For prompt germination the seed of Russian olive (Elaeagnus angustifolia L.) required 9 to 12 weeks of after-ripening at a temperature of 5° C. When fruit and endocarp were removed, 50–60% of the non-after-ripened seed germinated. Complete germination was obtained by removing the endocarp and the seed coats. The germination inhibition appeared to be related to non-leachable inhibitors in both of these structures, and their influence was almost entirely restricted to the radicle end of the embryo. Kinetin was very effective in breaking the dormancy linked to the seed coats but did not influence dormancy when the endocarp was present.
Received for publication November 5, 1969. Contribution No. 210, Department of Plant Science, University of Manitoba.
This research was supported by a grant from the National Research Council of Canada.
Present address: Research Station, Research Branch, Canada Department of Agriculture, St. Jean, Quebec.