Abstract:

A plantlet regeneration protocol was developed for Pinus elliottii. Adventitious bud formation was obtained from mature embryos of P. elliottii by a soaking-treatment with liquid medium containing 6-benzyladenine (6-BA) at different concentration for 12, 24 and 36 h respectively, followed by culture on 1/2 modified Gresshoff and Doy medium (GD) without hormone. The highest differentiation frequency and the largest number of adventitious buds were obtained in the pretreatment with 60 mg·L^-1 6-BA for 12 h, 24 h respectively. Relatively high frequencies of large buds were obtained after a pretreatment with 30 mg·L^-11 6-BA for 24 h. On subculture medium, adventitious buds derived from a pretreatment with 60 mg·L^-1 6-BA elongated slowly and were smaller in size than those pretreated with 30 mg·L^-1 6-BA. The concentration of 6-BA up to 80 mg·L^-1 would inhibit the formation of adventitious buds. Roots were formed when excised shoots planted on 1/2 GD supplemented with naphthalene acetic acid (NAA) 0.05 mg·L^-1 for 4 weeks, and the rooting rate was 50%. The survival rate was 60% when the rooting shoots were moved to the greenhouse.

Key words: Pinus elliottii, mature embryo, adventitious bud, plantlet regeneration