Propagation of Ornamental Plants
18(3): 77-86, 2018
IN VITRO PROPAGATION OF ‘LAZARUS’ SPECIES THUJA SUTCHUENENSIS FRANCH.
Jiangqun Jin1*, Quanshui Guo2, Suying Han3, Li Zhu4, Yanqin Liu1, and Yuhan Chen1
1 Chongqing Institute of Medicinal Plant Cultivation, 34 Foshan East Road, Sanquan Town, Nanchuan District, 408435 Chongqing, China, *Fax: + 86 023 714 80128,
2 Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, State Key Laboratory of Forest Ecological Environment and Forestry Bureau, No. 1 Courtyard Dongxiaofu, Xiangshan Road, Haidian District, 100091 Beijing, China
3 Laboratory of Cell Biology, Research Institute of Forestry, Chinese Academy of Forestry, No. 1 Courtyard Dongxiaofu, Xiangshan Road, Haidian District, 100091 Beijing, China
4 Inspection and Testing Center of Wuhai City, 13 Chuangye Road, Binhe District, 016000 Wuhai City, Inner Mongolia Autonomous Region, China
Thuja sutchuenensis Franch. is a ‘Lazarus’ species endemic to the limestone karst forests in the Daba Mountains of China. This species is critically endangered due to reproductive problems. The micropropagation of young T. sutchuenensis through axillary shoots was reported. Axillary shoots were grown on four media supplemented with different combinations of plant growth regulators (PGRs) for multiplication and three media supplemented with activated charcoal (AC) for elongation. The greatest capacity for axillary shoot induction was achieved on half-strength Schenk and Hildebrandt (SH) medium with 2 mg l-1 6-(4-Hydroxy-3-methylbut-2-enylamino) purine (Zeatin), and the Gupta and Durzan (DCR) medium supplemented with 2 g l-1 AC was the most suitable medium for shoot elongation. However, the axillary shoot tips began to die after repeated subcultures were grown on half-strength SH medium. Therefore, DCR was the best medium for the growth of T. sutchuenensis axillary shoot tips, but half-strength SH can serve as an occasional multiplication medium to increase the number of shoots, if necessary. It is important for media with PGRs to be alternately replaced with AC-supplemented media to avoid plantlet vitrification or browning caused by the accumulation of PGRs or secondary metabolites in repeated subcultures. The ex vitro cultured shoots immersed in 200 mg l-1 IBA rooted after 3 months of culture, with a rooting rate of 61.3%.
Key words: coniferous, endangered species, in vitro, ex vitro, micropropagation, rooting