Gibberellic Acid Promotes Seed Germination in Penstemon digitalis cv. Husker Red

Authors

Anderson Machado de Mello, Universidade Federal de Santa Maria
Nereu Augusto Streck, Universidade Federal de Santa Maria
Erin E. Blankenship, University of Nebraska-LincolnFollow
Ellen Paparozzi, University of Nebraska–LincolnFollow

Document Type

Article

Date of this Version

2009

Citation

HORTSCIENCE VOL. 44(3) JUNE 2009

Comments

Copyright 2009 American Society for Horticultural Science. Used by Permission.

Abstract

Penstemon seed often shows an inconsistent or a low germination percentage. Although most select cultivars are propagated by cuttings, for export to other countries, seed is preferred. Three experiments were conducted to determine if soaking seed in gibberellic acid (GA₃) would increase seed germination of Penstemon digitalis cv. Husker Red. GA₃ concentrations used were 0, 10, 50, 100, 200, and 500 mg∙L^–1 (first experiment); 0, 500, 1000, and 1500 mg∙L^–1 (second experiment); and 0, 500, and 1000 mg∙L^–1 (third experiment). The first and second experiments were conducted in a growth chamber, whereas the third experiment was conducted in both a growth chamber and greenhouse with seeds either covered or not covered by the mix. In all experiments,GA₃ increased the percentage and rate of seed germination. The 1000 mg∙L^–1 GA₃ was the best treatment. In the third experiment, percentage and rate of seed germination were the highest for seeds grown inside of the growth chamber, probably as a result of the consistency of temperatures and darkness. In the greenhouse, the percentage of seeds that germinated and the rate of germination were similar whether or not the seeds were covered with mix and whether they received either the 500 or 1000 mg∙L^–1 GA₃ treatment.