Breaking of seed dormancy in Iris suaveolens Boiss. et Reuter under in vitro conditions

Iris species have great economic importance for their use in ornamental and pharmaceutical industry. Flora of Turkey reports about 43 local taxons of which 16 are endemic. Iris suaveolens Boiss. et Reuter is an endemic species with high seed dormancy and has high tolerance to cold and drought. This study focused on seed dormancy break of I. suaveolens under in vitro conditions. In the first experiment, the seeds were given stratification treatment on MS medium containing different concentrations of BAP with or without NAA. The 2nd experiment reports effects of alternative combinations of cold (at 4°C, 24 h dark) – warm (16 h light photoperiod) conditions on medium containing different concentrations of plant growth regulators on agar solidified MS medium. Both experiments showed about 8.33% seed germination against 64.5% seed viability as confirmed by tetrazolium test. All germinating seeds were abnormal and very weak. In the third experiment, 10 minutes acid scarified seeds cultured at 24°C in 16 h light photo period on MS medium achieved 60.0% germination. Similar treatment under cold + dark condition was inhibitory and failed to show identical results. This underlines the importance of acid scarification, photoperiod and warm treatments of I. suaveolens seeds to break seed dormancy. All germinated seeds showed normal growth and development under field conditions.