Full Length Research Paper

Methods to break seed dormancy of Astragalus cyclophyllon

A.R. Keshtkar, H. R. Keshtkar*, S. M. Razavi and S. Dalfardi

Faculty of Natural Resources, University of Tehran, Karaj, Iran.

*Corresponding author. E-mail: hkeshtkar97@yahoo.com.

Accepted 20 August, 2008

The aim of this study was to enhance the germination rate of Astragalus cyclophyllon seeds which have a very low germination rate under normal conditions. The seeds were soaked for 72 h in 100, 200, 300, 400 and 500 ppm gibberellic acid (GA₃) solution, H₂SO₄ concentrations (50 and 98%) at two treatment times (5 and 10 min) and 60, 80 and 100ºC hot water at two treatment times (5 and 10 min) before placing in Petri dishes. The fresh seeds (non-stratified) of A. cyclophyllon had 55% germination. Analysis of variance indicated that both GA3 and H₂SO₄ concentrations had significant effects on seed germination and final germination percentage. The highest germination percentage (81%) was obtained when the seeds were treated with 500 ppm GA₃. The results showed that hot water treatments are not useful methods for breaking the seeds dormancy.

Key words: Chemical stratification, gibberellins, mechanical scarification.