Zelkova sinica Schneid. is naturally distributed in the northwestern region at an altitude of 300 to 2500 m in China (Chen and Huang, 1999; Editing Committee of Zhongtiao Mountain Tree species, 1995). It has been introduced into Korea, Japan, and the United States (Hawley, 1971). Z. sinica is one of the most popular landscape plants in China because of its adaptability to varied environmental conditions, strong disease resistance, outstanding crown, and beautiful fall color (Jin and He, 2005). Its hard wood is widely used for making furniture because of its beautiful and durable texture. Z. sinica has become a rare and endangered species in China as a result of overexploitation of the wild plants for commercial purposes and inefficient propagation methods (Fu and Jin, 1992). Seed propagation of Z. sinica is limited because seed germination was very low (10% to 20%) (Dou et al., 2009), and propagation of a specific cultivar is impossible because of seedling variability. Vegetative propagation of Z. sinica by cuttings may be subject to seasonal variations. There is an urgent need to develop an efficient protocol for the large-scale propagation of Z. sinica to meet the ever-increasing demand, conserve its germplasm, and genetic diversity.
Micropropagation offers a rapid means of clonal regeneration for reforestation, gardening, and germplasm conservation (Fenning and Gershenzin, 2002). Gao et al. (1996) reported that embryos, cotyledons, hypocotyls, terminal buds, and single nodes containing axillary buds of Z. serrata could regenerate in vitro shoots. Ito and Kondo (1995) found that BA was a good cytokinin for shoot induction from axillary buds of Z. serrata (Thunb.) Makino. Jin et al. (2009) reported a successful protocol of in vitro regeneration of Z. schneideriana using leaf explants. However, little information is available for plant regeneration of Z. sinica. The aim of this study was to develop in vitro regeneration and rooting for Z. sinica from immature embryos.
Biroščĺková, M., Spišáková, K., Lipták, Š., Pichler, V. & Ďurkovič, J. 2004 Micropropagation of mature wych elm (Ulmus glabra Huds.) Plant Cell Rpt. 22 640 644
Chen, H.Y. & Huang, C.G. 1999 Ulmaceae, p. 385. In: Editorial Committee of Chinese Floral (ed.). Flora Republicae Popularis Sinicae. Vol. 22. Science Press, Beijing, China
Dou, Q.Q., Jiao, X.J., Zhang, M., He, K.Y. & Huang, L.B. 2009 Physiological response of Z. schneideriana seedlings in the soil under NaCl stress Acta Botanica Boreali-Occidentalia Sinica 29 2063 2069
Editing Committee of Zhongtiao Mountain Tree species 1995 Zhongtiao Mountain tree species. Forestry Press, Beijing, China
Fenning, T.M. & Gershenzin, J. 2002 Where will the wood come from? Plantation forests and the role of biotechnology Trends Biotechnol. 20 291 296
Fu, L.G. & Jin, J.M. 1992 Plants red book of China—Rare and endangered plants. Vol. I. Science Press, Beijing, China
Ghimire, B.K., Seong, E.S., Goh, E.J., Kim, N.Y., Kang, W.H., Kim, E.H., Yu, C.Y. & Chung, I.M. 2010 High-frequency direct shoot regeneration from Drymaria cordata Willd. leaves Plant Cell Tissue Organ Cult. 100 209 217
Irvani, N., Solouki, M. & Omidi, M. 2010 Callus induction and plant regeneration in Dorem ammoniacum D., an endangered medicinal plant Plant Cell Tissue Organ Cult. 100 293 299
Ito, R. & Kondo, T. 1995 Tissue culture of axillary buds and seedlings of Zelkova serrata Bulletin of the National Forest Tree Breeding Center 13 27 32
Jin, X.L., Zhang, R.Q., Zhang, D.L., He, P. & Cao, F.X. 2009 In vitro plant regeneration of an endangered Zelkova schneideriana Hand.-Mazz. from leaf explants J. Hort. Sci. Biotechnol. 84 415 420
Lloyd, G. & McCown, B. 1980 Commercial feasible micropropagation of mountain laurel Kalmia latifolia by use of shoot tip culture Comb. Proc. Intl. Plant Propagators Soc. 30 421 427
SAS Institute Inc 2011 JMP, Version 7. SAS Institute Inc., Cary, NC
Susmita, S., Shukla, S.K. & Mishra, S.K. 2009 In vitro plant regeneration from seedling explants of Stereospermum personatum D.C.: A medicinal tree Trees Structure and Function 23 409 413
Thakur, R.C. & Karnosky, D.F. 2007 Micropropagation and germplasm conservation of Central Park Splendor Chinese elm (Ulmus parvifolia Jacq. ‘A/Ross Central Park’) trees Plant Cell Rpt. 26 1171 1177