杨树派间远缘杂种小胡杨(Populus simonii×P.euphratica)组培快繁体系的构建

Construction of Rapid Propagation System for Tissue Culture of Intersectional Hybrid Populus simonii×P.euphratica

小胡杨是小叶杨和胡杨远缘杂交选育出的抗旱、耐盐碱优良品种,但是其硬枝扦插生根率低,限制了其大面积推广种植。构建小胡杨组培快繁体系既可实现良种快繁,又可为其持续遗传改良奠定基础。本研究以小胡杨无菌苗为材料,分别利用完全随机区组和单因素试验设计筛选出叶片不定芽再生及生根的适合培养基,并初步探索了再生植株的移栽条件。结果显示,小胡杨叶片不定芽再生的最佳培养基为MS+0.4 mg/L6-BA+0.4 mg/L KT+30 g/L蔗糖+6 g/L琼脂(pH=5.8~6.0),叶片分化率可达(97.61±4.12)%,平均每个外植体产生(1.80±0.66)个不定芽;最佳生根培养基为1/2MS+0.3 mg/L IBA+30 g/L蔗糖+6 g/L琼脂(pH=5.8~6.0),生根率可达(98.67±0.13)%,接种9 d就可生根,接种30 d后,平均根长达(7.27±0.41)cm,平均苗高为(6.44±0.07)cm,单株叶片数达(10.47±0.35)片;将生根培养30 d的再生植株移栽到草炭土∶珍珠岩∶蛭石=3∶1∶1混合的基质中,15 d后成活率可达83.33%。小胡杨组培快繁体系的建立,为实现其无性系大规模繁殖提供了技术支持,同时也为继续开展小胡杨双二倍体诱导奠定了基础。

Populus simoni×P.euphratica is a drought-tolerant and salt-tolerant variety derived from distant hybridization between P.simoni and P.euphratica.However,its hardwood cuttings have a low rooting rate,which limits its large-scale application in forestry plantation.Construction of rapid propagation system for tissue culture of P.simoni×P.euphratica could not only realize the rapid propagation of the variety,but also lay the foundation for its continuous improvement.In this study,sterile seedlings of P.simoni×P.euphratica were used to screen out the suitable medium for leaf adventitious bud regeneration and rooting based on completely randomized block and single factor experimental designs respectively,and the transplanting conditions of the regenerated plants was explored.The results showed that the best medium for adventitious bud regeneration from leaf explants was MS+0.4 mg/L 6-BA+0.4 mg/L KT+30 g/L sucrose+6 g/L agar(pH=5.8~6.0),and the leaf differentiation rate reached(97.61±4.12)%and the average number of adventitious buds per explant was(1.80±0.66).The best rooting medium was 1/2MS+0.3 mg/L IBA+30 g/L sucrose+6 g/L agar(pH=5.8~6.0),and the rooting rate was(98.67±0.13)%.It could take root after 9 days of inoculation.After 30 days of inoculation,the average root length was(7.27±0.41)cm,the average seedling height was(6.44±0.07)cm,and the number of leaves per plant reached(10.47±0.35).The regenerated plants after rooting for 30 days could be transplanted into the mixture of peat soil:perlite:vermiculite=3:1:1,and the survival rate reached 83.33%after 15 days.In this study,the establishment of rapid propagation system for tissue culture of P.simoni×P.euphratica provided technical support for the large-scale clonal propagation of the P.simoni×P.euphratica variety,and laid the foundation for P.simoni×P.euphratica amphidiploid induction as well.