Effect of prechilling and GA3 on seed germination of Ferula assa-foetida and Prangos ferulacea

Dormancy breaking and germination requirements were investigated in seeds of Ferula assa-foetida L. and Prangos ferulacea (L) Lindl. Seeds of both species were collected from south and central rangelands of Iran and were subjected to different treatments. The evaluated treatments included various levels of gibberellic acid (GA3), prechilling and a combination of GA3 and prechilling (GA-prechilling). In contrast to treated seeds, non-treated seeds did not germinate. Germination of both species increased at higher concentrations of GA3. In the case of F. assa-foetida the highest germination percentage (52%) was obtained when the seeds were treated with 250ppm GA-prechilling. For P. ferulacea seeds, the highest germination percentage (73%) was found when exposed to 1000ppm GA-prechilling. Both species (especially P. ferulacea) responded positively to different periods of prechilling (30/60 d). For both species, germination rate was positively correlated with germination percentage.