NAA、2,4-D对崇明水仙(Narcissus tazetta var.chinensis)愈伤组织的诱导及再生的不同影响

目前水仙组织培养过程中愈伤组织的诱导是一大难题.本文以带鳞片的鳞茎盘为外植体,研究了2,4-D、NAA 2种类型的生长素对水仙组织培养中愈伤组织诱导的影响.结果表明,高浓度的2,4-D (3.0～4.0 mg/L)结合6-BA能诱导无色瘤状愈伤组织,中等浓度的2,4-D (0.5 mg/L)有利于芽点的诱导和瘤状愈伤组织的增殖,而较低浓度的2,4-D (0.1 mg/L)有利于诱导出小鳞茎,也能促使瘤状愈伤组织再生成苗.而NAA结合6-BA不能诱导愈伤组织的形成.高浓度的NAA不仅诱导未分化的分生组织细胞分裂,也能促进分化的细胞进行分裂,从而使形成白色凸起状结构.另外,培养基中这2种激素互换可以使组织培养过程中形成的愈伤组织或白色突起发生相互转换.这些结果说明,水仙组织培养过程中愈伤组织的诱导和不同形态的器官发生与培养基中生长素种类和浓度关系密切.

Effects of NAA and 2,4-D on the Induction of Calli and Organogenesis in Narcissus tazetta var.chinensis

It is still a challenging issue to induce growth of calli in tissue culture of Narcissus.Here,we compared the effects of 2,4-D and NAA on the induction of calli using explants of bulb scales of Narcissus tazetta var.chinensis.The results showed that morphogenesis induced by the two auxins was significantly different.Higher concentration of 2,4-D (3.0~4.0 mg/L),in combination of 6-BA,demonstrated the capacity to induce colorless embryogenic calli.This kind of callus can be easily regenerated and proliferated.Moderate concentration of 2,4-D (0.5~1 mg/L) stimulated the production of shoot buds from scale explants.Additionally,such moderate concentration was also effective in the proliferation of somatic embryogenic calli.Low concentration of 2,4-D (0.1 mg/L) was sufficient for the regeneration of plantlets from colorless calli.NAA in combination with 6-BA did not showed the capacity of inducing embryogenic calli from scales.High levels of NAA promoted the development of white bulges,which developed from active cell division of both differentiated cells and meristem cells.Furthermore,the exchange of different type of auxin also altered the type of morphogenetic features,i.e.replacement of NAA by 2,4-D altered the type of morphogenetic features from white bulges to embryogenic calli,and vice versa.These results suggested that different calli induction and organogenesis were dependent on the auxin type and their concentrations in the medium.This study provides the theoretic foundation for the rapid culture of Narcissus tazetta var. chinensis.