石斛‘火鸟’茎尖诱导类原球茎的组培快繁技术研究

Tissue Culture of Soot Apices for Induction of PLBs of Dendrobium nobile ‘Huoniao'

以石斛‘火鸟’Dendrobium nobile‘Huoniao’茎尖为外植体,用不同植物生长调节剂及不同基础培养基对原球茎的诱导、增殖、分化及生根培养进行试验。结果表明,类原球茎的诱导最适宜的基本培养基为MS,生长调节剂为0.2 mg·L^(-1)的2,4-D,诱导率达到92%。不同浓度NAA处理,以1.0 mg·L^(-1)的增殖效果最好,类原球茎生长较好,增殖系数达3.55倍。类原球茎的分化培养以0.5 mg·L^(-1) NAA效果最好。添加5%椰乳,1 g·L^(-1)活性碳最有利于石斛壮苗生根。试验显示‘火鸟’类原球茎诱导、增殖和分化培养条件分别为:MS+2 mg·L^(-1) 6-BA+0.5mg·L^(-1) NAA+0.2 mg·L^(-1) 2,4-D;1/2MS+0.05 mg·L^(-1) KT+1.0 mg·L^(-1) NAA;1/2MS+0.5 mg·L^(-1) 6-BA+0.5 mg·L^(-1)NAA。在光照培养箱中光照强度1 500 Lx和温度25℃条件下,‘火鸟’组培苗移栽成活率达86%。

Experiments were conducted on induction, multiplication, differentiation and rooting of shoot apices of Dendrobium nobile ‘Huoniao＇ as explants treated by different plant growth regulators and basic medium. The results showed that the best basic medium and growth regulator was MS and 0.2 mg·L^-1 of 2,4-D for induction of protocorm-like bodies（PLBs） with induction rate of 92%. 1.0 mg·L^-1 of NAA had the best effect of proliferation of PLBs, with growth coefficient of 3.55 time. 0.5 mg·L^-1 of NAA had the best effect of differentiation of PLBs. Addition of 5% coconut milk and 1.0 g·L^-1 activated carbon had advantages of rooting and seedling growth. The conclusions for the experiments were as follows, the best condition for induction, proliferation and differentiation was MS ＋2 mg·L^-1 6-BA ＋ 0.5 mg·L^-1 NAA ＋0.2 mg·L^-1 2,4-D, 1/2MS ＋ 0.05 mg·L^-1 KT ＋ 1.0 mg·L^-1 NAA, and 1/2MS ＋0.5 mg·L^-1 6-BA ＋ 0.5 mg·L^-1 NAA. The survival rate of in-vitro plantlets was 86% under 25℃ and 1 500 Lx light intensity in light incubator.