湿地松成熟合子胚直接器官发生及植株再生

Plantlet Regeneration via Organogenesis from Mature Embryos of Pinus elliottii

以湿地松成熟胚为外植体诱导不定芽发生，初步建立植株再生体系。先用含不同浓度6-BA的液体培养基处理湿地松成熟胚12～36h，吸干后转移到无激素的培养基上培养。6周后，经60mg·L。6-BA液体培养基预处理12h的胚不定芽诱导率最高达69％，预处理24h平均每个外植体产芽数达到最高（9～12个），但芽体较小，在继代培养基中伸长较慢；经30mg·L^-1 6-BA液体培养基预处理的胚不定芽诱导频率较低，仅25％～38％，但芽体健壮，在继代培养基中伸长较快；6-BA浓度大于80mg·L^-1时不利于不定芽分化。不定根诱导的研究结果表明，NAA对不定芽生根具有促进作用，在改良1／2GD＋NAA005mg·L^-1培养基中培养4周后，生根率达50％，移栽成活率为60％左右。

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 ^-1 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 /he rooting shoots were moved to the greenhouse.