Propagation of Ornamental Plants
20(1): 12-21, 2020
SOMATIC EMBRYOGENESIS AND HISTOLOGICAL OBSERVATION
OF XANTHOCERAS SORBIFOLIA BUNGE.
Na Zhang1,2, Yunxiang Zhang1, Jinping Guo3*, and Shujun Chang1
1 College of Forestry, Shanxi Agricultural University, 1 Mingxian South Road, 030801 Taigu, Shanxi, China
2 Shanxi Academy of Forestry Sciences, 105 Xinjian South Road, 030012 Taiyuan, Shanxi, China.
3 College of Graduate Studies, Shanxi Agricultural University, 1 Mingxian South Road, 030801 Taigu, Shanxi, China, *Fax: + 86354 6288 227, *E-mail: email@example.com
An efficient and reproducible system for direct somatic embryogenesis was established in Xanthoceras sorbifolia Bunge, using cotyledon explants of immature seeds. The most important factor inducing somatic embryogenesis was the type and combination of plant growth regulators. The embryogenic callus was induced on Murashige and Skoog (MS) medium supplemented with 2,4-Dichlorophenoxyacetic acid (2,4-D) alone, and somatic embryos were induced from the callus. The highest frequency of callus induction (100.0%) was observed on medium supplemented with 1.0 mg l-1 2,4-D. The highest frequency of somatic embryo (10.8%) was induced on medium with 1.0 mg l-1 2,4-D. Somatic embryos were induced directly on MS medium containing N6-benzyladenine (BA) or 1-Phenyl-3-(1,2,3,-thiadiazol-5-yl) urea (Thidiazuron, TDZ) in combination with α-naphthaleneacetic acid (NAA). BA was more effective than TDZ in combination with NAA in the frequency of somatic embryo induction. The highest frequency of somatic embryo induction (89.4%) was observed on medium supplemented with 2.0 mg l-1 BA and 0.2 mg l-1 NAA. Concentrations of BA lower or higher than 2.0 mg l-1 resulted in significant decrease of the frequency of somatic embryo induction. The percentage of conversion was 73.6% when somatic embryos were cultured on the MS medium supplemented with 2.0 mg l-1 BA and 0.2 mg l-1 NAA. Histological analysis and scanning electron micro-photographs confirmed the direct initiation, development, and germination of somatic embryos from cotyledon explants.
Key words: cotyledon explants, in vitro, micropropagation, ornamental plant, plant growth regulator