“固液双层”培养法诱导马铃薯‘米拉’试管薯的研究

Microtuber induction of potato cultivar ‘Mira’ by “solid + liquid double-layer” culture

该研究以马铃薯‘米拉’品种的脱毒试管苗为材料,采用"固液双层"的培养方式,通过正交试验对其试管苗壮苗生长阶段和试管薯诱导阶段的培养基进行优化,并通过单因素试验研究蔗糖浓度、光照条件和CCC浓度对试管薯结薯的影响。结果表明:在"固液双层"培养中,‘米拉’壮苗培养阶段优化的培养基为改良MS培养基(硝酸铵为2 000 mg·L^(-1)、硝酸钾为2 000 mg·L^(-1))+500 mg·L^(-1)CCC+0.1%活性炭+0.1mg·L^(-1)DA-6+1 mg·L^(-1)6-BA+0.1 mg·L^(-1)NAA+3%蔗糖+6 g·L^(-1)琼脂,pH 5.8。试管薯诱导及生长阶段优化的培养基为MS_1培养基(微量元素和铁盐的用量为MS培养基的2倍)+1.5%活性炭+4 mg·L^(-1)6-BA+8%蔗糖。在试管薯诱导阶段,弱光4 h·d^(-1)培养诱导的试管薯,结薯指数、大薯率、薯块重量均优于暗培养。"固液双层"培养是一种低成本的方法,在组织培养室内就可以大量繁殖‘米拉’试管薯,并且能增加原种的数量,这种方法也能用于马铃薯其他栽培品种试管薯的诱导。

Virus-free plantlets of potato cultivar‘Mira’were used as experimental material to induce potato microtuber by a two-step culture method.In the first step,nodal cuttings(with one or two leaf)of potato plantlets were inoculated solid medium for culturing vigorous potato plantlats.After 20 d,liquid medium was added on the solid medium to proceed to the second step for induction of potato microtuber.The optimum culture media at the stages of culturing vigorous potato plantlets and induction of potato microtuber were obtained by means of orthogonal design,and the effects of sucrose concentration,light condition and CCC concentration on induction of potato microtuber were also studied.The results were as follows:the optimal medium at the stage of culturing vigorous potato plantlets was modified by MS medium(NH 4 NO 3 was changed to 2 000 mg·L^-1 and KNO 3 was changed to 2 000 mg·L^-1 in MS medium)+500 mg·L^-1 CCC+0.1%activated carbon+0.1 mg·L^-1 DA-6+1 mg·L^-1 6-BA+0.1 mg·L^-1 NAA+3%sucrose+6 g·L^-1 agar,pH 5.8,the optimal medium at the stage of induction of potato microtuber was MS 1 medium[two times of FeSO4(Na2 EDTA)and trace elements in MS medium]+1.5%activated carbon+4 mg·L^-1 6-BA+8%sucrose.The results also showed that illumination with dim light for 4 h·d^-1 could obtain potato microtubers with higher frequency of tuberization and big microtubers than dark treatment.The results indicated that“solid+liquid”double-layer culture can be applied for mass propagation of potato tubers‘Mira’at low cost in the plant tissue culture room,and can increase the number of pre-elite seed potatoes.This method can also be used for the production of microtuber of other potato cultivars.