In vitro induction of tetraploidy in Linum album Kotschy ex Boiss. using oryzalin treatment

Linum album Kotschy ex Boiss. is one of the endemic species of Linaceace family in Iran, having podophyllotoxin (PTOX) metabolite. This substance is a pharmaceutically important natural product belonging to the lignans group. It is used as a precursor for the synthesis of important anti-cancer drugs. Industrial production of this component is not economically feasible because of its complex chemical structure. Therefore, various strategies have been used to increase the production of PTOX in plants. In this study, tetraploidy was induced in nodal segments with different concentrations of oryzalin (0, 15, 25, 50 µM) for 24, 48, 72 and 96 h. The results indicated that the viability and the number of produced shoots in each nodal segment were reduced by increasing concentrations and times of oryzalin. Tetraploid plants were identified by flow cytometry, and 2C DNA content of diploids and tetraploids were estimated to be 4.34 and 8.36 pg, respectively. The highest induction efficiency percentage (19%) of tetraploidy was achieved from 25 µM of oryzalin for 48 h. Tetraploid induction caused 1.66 and 1.48 fold-increase in PTOX content in the leaves and stems of tetraploids compared with those of diploids, respectively. The results of this study indicated that the induction of tetraploidy could be an effective technique to increase this valuable metabolite in Linum album.