Abstract:

A somatic embryogenesis system from immature zygotic embryos of Pinus thunbergii was established. The effects of basic medium, 2,4-D and 6-BA on embryogenic callus induction were studied, and the effects of ABA and PEG on somatic embryo maturation and plant regeneration were investigated. The results showed that cultured on DCR medium supplemented with 4 mg·L^-12,4-D and 2 mg·L^-16-BA, the embryogenic callus induction rate was 3.33%; and on DCR medium containing 30 mg·L^-1 ABA and 25 g·L^-1 PEG, the number of somatic embryo per gram embryogenic callus was up to 72, and the somatic embryo germination rate was 63.8% and plantlet conversion rate from the germinated somatic embryos was 43.5%. High quality somatic embryos could improve the germination rate and plantlet conversion rate. Up to 50% of the transplanted plantlets were successfully survived one month in soil. This study would provide a new way for rapid and large-scale propagation of wilt-resistant P. thunbergii.

Key words: Pinus thunbergii, embryogenic callus, somatic embryo, plantlet regeneration