优良木薯品种新选048离体快繁技术

Rapid propagation in vitro technology for fine cassava variety Xinxuan 048

【目的】探讨木薯新品种新选048的离体快速繁殖技术，为扩大种苗生产提供参考。【方法】以带腋芽的幼嫩茎段为外植体，研究不同季节取材、不同灭菌方法、不同用量植物生长调节剂以及不同培养方式对新选048离体快繁过程的影响。【结果】相对于冬季、夏季，春季采集的腋芽萌发快、生长势旺，污染率为22．1％，成活率为69．3％。在8～12min内，随着0．1％HgCl2、2．0％NaCl0灭菌时间的延长，外植体污染率降低，但褐化率随之升高；不同处理中，以0．1％HgCl2处理10min对外植体的灭菌效果较好。在继代增殖培养基中，随着6-BA用量（0．02～1．00mg／L）的升高，诱导的愈伤组织长度、鲜重和干重均不断增加，而不定芽的增殖系数、组培苗的鲜重和干重呈先升高后降低的变化趋势，但不定芽高度逐渐降低；以添加0．05mg／L6-BA的增殖效果最好，最高增殖系数为6．1倍，组培苗鲜重和干重综合表现较好。采用固体培养基培养的木薯不定芽增殖系数和组培苗干重最高，且诱导的不定芽长势均一、生长势旺；采用液体培养基培养的不定芽株高和组培苗鲜重最高，而间歇式浸没培养诱导的木薯不定芽增殖系数、株高、组培苗鲜重和干重均较低。在1／3MS＋0．02mg／LNAA＋20．0g/L蔗糖＋6．0g/L琼脂粉的生根培养基中不定芽生根率达100．0％，根多且长，呈乳白色。【结论】成功建立了木薯品种新选048以带腋芽的茎段为外植体的快速繁殖体系，可为其种苗生产提供新的途径。

[Objective]The present study was conducted to develop rapid propagation technology of cassava variety Xinxuan 048 in order to provide references for expanding its seed-using seedling prodution. [Method]The young stems with axillary bud was used as explants, the effects of different sampling seasons, sterilization methods, various concentra- tion of 6-BA and different culture media on the process of plautlets culture were investigated. [Result]As compared with samling in winter and summer, the axillary buds of stem samped in spring germinated lastly and grew well, it had low contamination rate of 22.1% and higher survival rate of 69.3%. In the range of 8-12 min, the explants showed decreasing contamination rate and increasing browning rate with prolonging sterilizing time of 0.1% HgCl2 and 2.0% NaC10, and the sterilizing effects was found the best by sterilization of 0.1% HgCl2 for 10 min. In the process of subculture, with the increase of 6-BA（0.02-1.00 mg/L）, the induced callus presented increasing length, fresh and dry weight. The multiplication coefficient, fresh and dry weight of induced plantlets showed a change trend of increase at first and decrease later, while the height decreased gradually. The subculture medium adding with 0.05 mg/L 6-BA had the best muhiplication effects for higher fresh and dry weight of plantlet and the highest multiplication coefficient （6.1）. In half solid culture medium, the induced adventitious buds presented the highest coefficient and dry weight of plantlets, strong growth vigor in order. In liquid culture medium, the induced adventitious buds had the highest height and fresh weight. The induced adventitious buds by using TIS culture had the lower multiplication coefficient, height, fresh and dry weight. The suitable medium for rooting was 1/3MS＋0.02 mg/L NAA＋20.0 g/L sugar＋6.0 g/L agar, and the rooting rate was 100.0%, the induced root was long and white. [Conclusion]The rapid propagation system of cassava cultivar Xinxuan 048 is established by using stem with axillary buds, which would provide new method on producing seed-using seedling.