银杏胚的培养及不定芽的产生

Adventitious buds formation from immature or near mature embryo cultures of Ginkgo biloba

关键词:  银杏  未成熟胚  近成熟胚  不定芽

Key words:  Ginkgo biloba  immature embryo  near mature embryo  adventitious buds

摘要:

通过对银杏未成熟胚和近成熟胚的培养，研究其不定芽的发生情况。结果表明：（1）银杏的种胚存在生理后熟现象，10月上旬，胚未成熟，在360个种核中，小子叶胚数(1.0～3.0 mm)为26.1%，大子叶胚(3.0～5.0 mm)的种子数占总种核数的42.2%，种核的出胚率为71.1%；（2）大子叶胚和小子叶胚接种在不同的培养基上后，发现大子叶胚膨大，子叶伸长膨大，胚愈伤化程度小。而小子叶胚全部愈伤化，继续培养出现芽点，频率在35.0%以上；（3）大子叶胚继代在改良MS+0.2 mg•L 1IAA+0.75 mg•L 1 KT培养基后，发现子叶远基端有不定芽的产生，最高频率达20.0%；（4）近成熟胚在改良MS+NAA0.01 mg•L 1+6 BA1.0 mg•L 1培养基上，胚芽出芽率最高达42.5%，继续培养后发现有丛芽点的出现，再继续生长20 d后出现许多芽丛，芽数达3个，频率在30.0%以上。

Abstract:

The formation of adventitious buds of Ginkgo were studied by using near mature and immature embryos cultures. The results were as followed:(1)Ginkgo embryo had characteristic of physiological after ripening. The rate of small cotyledon embryos(1.0-3.0 mm) was 26.1%，the rate of large cotyledon embryos(3.0-5.0 mm)was 422% and the total rate of the seed with embryo was 71.1% in October； (2)The cotyledons from large cotyledon embryos became swollen and few callus was produced after cultured on different induction mediums，but the small cotyledon embryos of all could induced callus and the green spots were initiated on the surface of callus after subculuring two times； (3)The adventitious buds formed from cotyledon of large cotyledon embryos after subcultured on modified MS medium with 0.2 mg•L 1 IAA and 0.75 mg•L 1 KT. The highest emergence of adventitious buds was 20.0%； (4)The highest frequency of embryo bud germination of near mature embryos (42.5%)and the highest number of bundle buds per explant(3.0)were obtained on modified MS medium with 0.01 mg•L 1 NAA and 1.0 mg•L 1 6 BA.