Potential of Podophyllotoxin production in some Iranian ecotypes of Linum album under in vitro Condition

Linum album as one of the endemic perennial plants in Iran is a natural source of lignan compounds. In the present study, the seeds of L. album were collected from its natural habitats in four regions of Iran (Aliabad, Jowkar, Dasht-e Arzhan, Taleqan). The effects of ecotype and gibberellic acid (GA) pretreatment were evaluated on germination traits of L. album seeds in a factorial based on completely randomized design with four replications. Also, the capacity of studied ecotypes in regard to secoisolariciresinol (SECO), podophyllotoxin (PTOX) and 6-methoxy-podophyllotoxin (6-MPTOX) production was assayed under in vitro condition by high performance liquid chromatography (HPLC) based on completely randomized design with four replications. In all studied ecotypes of L. album, seed germination percentage, germination rate and seedling growth was significantly improved in response to GA pretreatment. The obtained sterilized seedlings were used as in vitro explants that were successfully propagated in MS medium without any growth regulators. The in vitro proliferation rate in ecotype of Jowkar in terms of shoot number and plantlet biomass was significantly higher than the other ecotypes. The highest SECO and PTOX contents were extracted in the Dasht-e Arzhan plantlets which were higher (up to four times) than the other ecotypes. Also, the plantlets of Dasht-e Arzhan, Taleqan and Jowkar ecotypes showed the highest content of 6-MPTOX. According to germination, morphological and phytochemicals traits, the ecotype of Dasht-e Arzhan can be considered as a good candidate for breeding programs of improving PTOX production in this plant.