Role of Temperature, Light and Growth Regulators in Germination in Anemone coronaria L

Abstract

The optimal temperature range for germination of achenes of the De Caen type of cultivated A. coronaria L. was 10-20°C. Continuous irradiation with white light retarded germination, particularly at supraoptimal temperature. The retardation was caused by the far-red component of the light. Blue light was inactive by itself but synergized with far-red. Gibberellic acid (GA₃) promoted gerrnin- ation only at supraoptimal temperature (25°C). Abscisic acid (ABA) inhibited germination more at 20 than at 15°C. Rinsing the achenes with water completely removed the inhibition caused by 40 p.p.m. ABA. GA₃ at a concentration of 100 p.p.m. partly overcame the inhibition caused by ABA. The growth retardants (2-chloroethyl)trimethylammonium chloride and Amo-1618 [2'-isopropyl-4'- (trimethylammonium chloride)-5'-methylphenyl piperidine-1-carboxylate] inhibited germination more at 20 than at 15°C; Amo-1618 was more inhibitory. GA₃ at concentrations of 10-1000 p.p.m. partly overcame the inhibition by 100 p.p.m. Amo-1618, but not that by 1000 p.p.m. Partial stripping or cutting of the pericarp enhanced germination whereas complete removal inhibited it. During the first 6 days of incubation under the optimal conditions the embryo grows within the endosperm, thus accounting for the minimum lag period of 6 days prior to emergence of the seedling from the pericarp.