Seed dormancy of beardless wildrye (Elymus triticoides Buckl.) [Germination, inhibition, oxygen]

The use of beardless wildrye (Elymus triticoides Buckl.) as a forage grass is limited by slow germination and poor stand establishment. Little research has been done on the germination of beardless wildrye. The purpose of this research was to study the germination behavior of beardless wildrye in an effort to define factors contributing to slow germination. We studied the effect of temperature on imbibition and germination, and the effects of stratification, seed size, embryo excision and high oxygen concentrations on germination. Temperature did not affect total imbibition, however, imbibition at 30 and 20 C induced greater germination when transferred to a 15-25 C alternating germination environment. The application of oxygen induced the greatest germination response of all treatments (57%). Excised embryos germinated rapidly and percentage germination was equal to viability of the seed lot. The response to oxygen and the rapid and complete germination of excised embryos indicates that dormancy in beardless wildrye is imposed by the outer coverings of the seed. Germination was not influenced by seed size.