NaOH scarification and stratification improve germination of Iris lactea var. chinensis seed

Abstract

Iris lactea seed is characterized mainly by physiological dormancy. Two experiments were conducted to investigate the effect of NaOH treatment and stratification on Iris seed germination. In Experiment 1, seeds were treated with 14.38 M NaOH for O to 28 hours. In Experiment 2, NaOH treated and nontreated seeds were stratified nnder 7 °C and moistened condition for 0 to 40 days. As results, NaOH treatment for 20 hours effectively removed seedcoat and improved germination percentage from 0% to 56% compared to control (0 hoars). However, germination percentage started to decrease after 20 hoars. Stratification for 40 days further improved germination percentage of NaOH treated seeds to >80%, but did not affected seeds without NaOH treatment. Results demonstrate that combination of NaOH treatment and stratification is an effective practice to break Iris seed dormancy and improve germination percentage.