Differences in free sterols content and composition associated with somatic embryogenesis, shoot organogenesis and calli growth of flax.

摘要

A single medium was used for induction of somatic embryogenesis and shoot organogenesis from flax (Linum usitatissimum) hypocotyls. With this system, a comparative study was performed to determine the free sterols content and composition in non-organogenic, shoot organogenic and embryogenic calluses as well as in regenerated shoots and somatic embryos grown under the same hormonal supplementation. Induction of somatic embryogenesis and shoot organogenesis of flax was associated with an increase oftotal sterols in the competent calluses and an increased ratio of stigmasterol to beta-sitosterol in derived embryos and shoots. On the contrary, in non-organogenic calluses, the ratio stigmasterol to beta-sitosterol decreased during the exponential growth phase due to a drastic rise in the beta-sitosterol content. This effect as well as callus growth were higher with 0.5 mg/litre 2,4-D than with 0.6 mg/litre IBA.