象牙白花兰种子及茎尖培养与原球茎形态发生

Seed and Shoot-tip Tissue Culture and Morphogenesis of Protocorms in Cymbi- dium eburneum var. parishii( Rchb.f.)Hook.f.

象牙白花兰授粉后 5个月的种子开始具有较高的萌发率 ;椰乳或适量激素有利于种子的萌发 ;种子在萌发后胚发育形成原球茎 ,原球茎经过增殖 ,分化出叶片和根系 ,形成完整的小植株。从播种到小植株的形成历时约 7个月。茎尖在MS+NAA 0 .1 +BA 3 .0 (单位 :mg·L-1,下同 ) +椰乳 1 0 %的培养基上诱导产生原球茎 ;原球茎在MS +NAA 0 .1 +BA 5 .0的培养基上增殖 ,在无激素培养基上分化成芽 ;小芽在附加 7%香蕉汁和 3 %马铃薯汁的 1 / 2MS培养基上诱导出根而再生完整小植株。不同pH值、光照强度和培养方式对增殖效果有显著影响。

A propagation method of Cymbidium eburneum var. parishii( Rchb.f.)Hook.f.by in vitro culture of seeds and shoot tips,and the morphogenesis of protocorms from the cultured seeds are described in this paper.The germination capacity of young seed was very low but became prominently higher when it reached five months old.Although seeds could germinate on basal medium,addition of coconut milk,or NAA and KT to the medium clearly stimualted the germination of seed.After germination,The embryos developed into PLBs,which latter multiplicated and differentiated into leaves and roots,to form complete plantlet.It took more than seven months for seeds to develop to plantlets after sowing.Protocorm like bodies(PLBs)were induced from shoot tip explants in MS medium supplemented with NAA 0.1mg·L -1 ,BA 3.0mg·L -1 and coconut milk 10%.PLBs multiplicated in MS medium supplemented with NAA 0.1mg·L -1 and BA 5.0mg·L -1 .Plantlets were induced from PLBs in the media without any hormone.Roots were induced in 1/2 MS medium supplemented with 7% banana juice and 3% potato juice.The multiplication rate of PLBs were influenced by different light intensity,culture state and pH value significantly.