卷荚相思组培快繁技术研究

目的]建立16年生卷荚相思优树组培快繁技术体系。方法]以16年生卷荚相思优树的当年新生枝条带腋芽茎段为材料,对卷荚相思外植体进行消毒、初代培养、增殖培养、生根培养和移植等。结果]表明:通过对16年生卷荚相思成年优树采条进行扦插,以扦插苗建立采穗圃,选取采穗圃中当年生健康无病虫害枝条的中段为外植体,最佳消毒方式为75%的酒精处理0.5 min和0.1%的升汞处理18 min,其存活率达69.33%,芽诱导率达86.67%;最佳初代培养基为改良MS+蔗糖40 g·L-1,出芽率为91.33%。最佳增殖培养基为MS+6-BA 0.5 mg·L-1+NAA 0.1 mg·L-1+蔗糖30 g·L-1,35 d增殖倍数可达3.50倍;最佳生根培养基为1/2 MS+IBA 0.25 mg·L-1+NAA 0.5 mg·L-1+蔗糖40 g·L-1,15 d生根率为96.11%;将生根苗移植至以沙为基质的营养杯中,存活率为71.11%。结论]研究解决了16年生卷荚相思成年优树外植体污染率高和芽诱导率低等问题,建立的组培快繁技术体系对今后加快卷荚相思良种选育及优质苗木大量扩繁具有重要作用。

Technique of Tissue Culture of Acacia cincinnata

Objective] To establish the technique system of tissue culture for 16-year-old Acacia cincinnata elite tree. Method] Newborn branches with axillary buds from 16-year-old elite tree were collected as explants to study the sterilization strategy, primary culture, multiplication culture, rooting and transplant of A. cincinnata. Result] A cutting orchard was established by using the newborn branches of 16-year-old A. cincinnata elite trees as cuttings. It was proved that the middle part of stem segments collected from the orchard was the best. As sterilized with 75% alcohol for 0.5 min and 0.1% HgCl₂ for 18 min, the survival rate and shooting rate of explants were 69.33% and 86.67% respectively; the best primary culture medium was modify MS+ sucrose 40 g·L^-1, with germination rate 91.33%; the highest multiplication index was 3.50 after 35 d cultured on MS+6-BA 0.5 mg·L^-1+NAA 0.1 mg·L^-1+sucrose 30 g·L^-1; the best medium for rooting was 1/2MS+IBA 0.25 mg·L^-1+ NAA 0.5 mg·L^-1+ sucrose 40 g·L^-1 with rooting rate 96.11% after cultured 15 d. The survival rate reached 71.11% after being transplanted the rooted plantlets to nutrition cup with sand. Conclusion] This study would help to resolve the problems of sterilization and shoot induction of mature A. cincinnata elite tree, and the tissue culture technique could contribute to A. cincinnata breeding program and large-scale seedling propagation.