杜梨组培苗两步生根技术体系优化

Optimizing two-step rooting techniques of in vitro cultured Pyrus betulifolia

为解决杜梨组培苗生根率低和移栽成活率低的问题,本研究以杜梨组培苗为试材,通过不定根诱导、不定根生长培养和试管苗驯化移栽环节,筛选出最适杜梨组培苗生长的培养基配方和炼苗方式。结果表明:1)健壮组培苗在添加了1.0mg/L吲哚乙酸(IAA)和1.0mg/L萘乙酸(NAA)的NN_(69)(Nitsch&Nitsch Medium)培养基中暗培养7d后进行不定根诱导,再转接至无生长素类物质的相同培养基中光照培养,组培苗生根率达96%;2)生根组培苗闭瓶炼苗和水培炼苗3周后移栽,成活率均达90%以上。综上所述,前期"高浓度生长素和黑暗培养"和后期"无激素和光照培养"的"两步生根法"适宜杜梨组培苗的生根诱导。杜梨组培苗生根技术的优化,为杜梨无性系砧木的商业化生产提供了技术支持。

In this study,to solve the problems of low rooting rate of Pyrus betulifolia somaclone and low survival rate of transplanting,in vitro shoots of Pyrus betulifolia were used to optimize the rooting medium for adventitious root induction and root growth,and training methods of plantlets.The results showed that:1)Ninety-six percent of in vitro shoots regenerated adventitious roots when the robust shoots were cultured on the NN_(69) medium supplemented with 1.0 mg/L IAA and 1.0 mg/L NAA under the darkness for 7 days,and then transferred to the same basic medium without auxins under lightening conditions;2)More than 90%of the rooted plantlets survived when hardened in closed jars or hydroponic for 3 weeks and transplanted in the greenhouse.In conclusion,the two-step rooting method including utilization of high concentration of auxins in culture medium combined with dark culture at the beginning and auxin-free medium with light culture at the second step is suitable to induce rooting of in vitro cultured P.betulifolia.Optimizing the rooting techniques of plantlets provided a technical support for commercially producing clonal rootstocks of P.betulifolia.