香榧体细胞胚发生的初步研究

Somatic embryogenesis of Torreya grandis ‘Merrillii'

以香榧Torreya grandis‘Merrillii’胚为外植体,研究了基本培养基、复合添加物、碳源以及植物生长调节物质对愈合组织形成的影响,筛选出胚性愈合组织诱导和增殖的适宜条件,并初步进行了体细胞胚的诱导与萌发试验。结果表明:Schenk and Hildebrandt(SH)是最佳基本培养基,碳源以蔗糖最好,在SH中添加谷氨酰胺,愈合组织诱导率显著高于其他处理,达50.8%;低浓度的萘乙酸(NAA)或2,4-二氯苯氧乙酸(2,4-D)能够促进愈合组织的诱导,NAA的促进作用比2,4-D明显,当NAA的质量浓度为0.1 mg.L-1时,愈合诱导率显著高于其他处理,达60.1%;SH+0.1 mg.L-1NAA+30 g.L-1蔗糖是愈合组织形成的最佳条件,SH+0.05 mg.L-1NAA+30 g.L-1蔗糖为胚性愈合组织形成和增殖的最适宜培养基;胚性愈合组织在添加有脱落酸(ABA)和聚乙二醇(PEG)6000的SH培养基上,可形成体胚,以1/2SH作为萌发培养基,体胚在1 200 lx光照下的萌发效果比黑暗条件下好。

To establish somatic embryogenesis protocols for Torreya grandis ＇Merrillii＇, immature embryos were used as explants. The effects of different basal mediums （SH, MS, BS）, organic additives （glutamine （Glu）, casein hydrolysate （CH）, myo-inositol）, carbon sources （sucrose, glucose, maltose）, and plant growth regula- tors （PGRs） （N6-benzylaminopurine （BA）, Kinetin （KT）, 2,4-dichlorophenoxyacetic acid （2,4-D） or BA, KT, a-naphthaleneacetic acid （NAA） for the initiation of primary callus were tested. Optimal PGRs for induc- tion and proliferation of embryogenic tissue were determined, and a study on somatic embryo induction （SH supplemented with 0.05 mg-L-1 6-BA and 0.25 mg.L-1 2,4-D, SH supplemented with 0.05 mg＇L-l 2,4-D and SH supplemented with 0.05 mg-L-~ NAA respectively） and germination （SH supplemented with ABA or PEG） was carried out. Results showed that callus initiation frequency for SH supplemented with Glu was significantly higher （P 〈 0.05） than other treatments, with 50.8%. The optimal carbon source was sucrose and the optimal concentration was 3%. To improve primary callus induction, an initiation medium containing a low concentra- tion of 2,4-D or NAA was most efficient. The highest callus induction frequency was with SH medium and 0.1 mg L-1 NAA. For formation and proliferation of embryogenie tissue, the optimal medium was SH supplemented with 0.05 mg L-1 NAA. When callus was inoculated onto 1/2 SH medium supplemented with ABA and PEG 6000, somatic embryos were produced. Germination quality of somatic 1 200 lx light compared to in the clark. [Ch, 3 fig. 3 tab. 21 ref.]