Germination of Setaria chevalieri caryopses

Abstract

Summary Germination studies were made on Setaria chevalieri caryopses (seeds). The seeds imbibed readily upon moist incubation. An after‐ripening period which followed a cyclic patlern was necessary for maximum germination. Freshly harvested seed germinated in the presence of light, but only very sporadically in the dark. The germination of dark incubated seed was improved if the seeds were subsequently exposed to light. This photodormancy became less pronounced with dry storage. Treatment with red light increased germination. but was reversed by far‐red light suggesting that a phytochrome system operates in the seeds. Sodium azide treatments did not stimulate germination in the dark but were effective in the presence of light.

EVIDENCE FOR AN ENDOGENOUS CYCLE OF DORMANCY IN DRY STORED SEEDS OF POA TRIVIALIS L.

“…Cyclic changes in seed dormancy occur in many species which exhibit seasonal patterns of emergence (Baskin & Baskin, 1978Froud-Williams, Drennan & Chancellor, 1984) but such changes have not been reported during dry-storage (Karssen, 1980/81a). However, Erasmus & van Staden (1983) have observed that caryopses of Setaria chevalieri germinated less after 10 weeks of dry-storage than either immediately after collection or after 24 weeks of dry-storage. Nonetheless, this represents a period of after-ripening to break post-harvest dormancy rather than cyclic changes per se.…”