Plant Regeneration via Somatic Embryogenesis in Larix principis-rupprechtii Mayr
Date
2021
Authors
Jiang, Shuaifei
Chen, Xiaoyi
Gao, Ying
Cui, Ying
Kong, Lisheng
Zhao, Jian
Zhang, Jinfeng
Journal Title
Journal ISSN
Volume Title
Publisher
forests
Abstract
Prince Rupprecht’s larch (Larix principis-rupprechtii Mayr) is a native conifer in North China with great economic and ecological values. Somatic embryogenesis (SE) is a powerful tool for the mass clonal propagation in plants. In this study, we described a high-efficiency SE system via indirect pathways and investigated the effect of genotype, culture conditions and phytohormones on SE. Immature zygotic embryos (IZEs) of L. principis-rupprechtii Mayr were used as explant materials. In the induction stage, embryogenic tissues (ETs) were induced on mLV medium supplemented with 2.0 mg L-1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg L-1 6-benzylaminopurine (6-BA). The initiation frequencies showed significant differences (p < 0.05) among 20 genotypes of open-pollinated mother trees with the highest induction frequency reaching 30%. For tissue proliferation, proliferation in liquid medium was more efficient compared with proliferation in semi-solid medium, providing a multiplication rate of 3.12 in an 8-day subculture period. As a necessary exogenous plant growth regulator (PGR) for somatic embryo maturation in conifers, abscisic acid (ABA) was optimized at 16 mg L-1 in this system. Next, an orthogonal test on osmotic pressure factors showed 50 g L-1 sucrose, 7 g L-1 phytagel and 75 g L-1 polyethylene glycol (PEG) was the optimal combination for somatic embryo maturation in L. principis-rupprechtii Mayr. Moreover, the dispersion culture method provided a more efficient somatic embryo maturation, up to 545 per gram of fresh weight (FW). Finally, 2 g L-1 of active charcoal (AC) was found to increase the somatic embryo germination rate to 63.46%. The improved protocol of SE will serve as a foundation for establishing mass propagation and genetic transformation of L. principis-rupprechtii Mayr.
Description
We would like to specially thank Dan Li from Southwest Forestry University of China for her foundational exploration work in this SE system and Deshui Yuan from the National Key Seed Base of Larch, Weichang, Chengde, China, for his great contribution to mother trees selection and cones collection.
Keywords
conifer, larch, somatic embryos, genotype, culture methods, phytohormones, Centre for Forest Biology
Citation
Jiang, S., Chen, X., Gao, Y., Cui, Y., Kong, L., Zhao, J., & Zhang, J. (2021). Plant regeneration via somatic embryogenesis in larix principis-rupprechtii mayr. forests, 12(1335), 1-16. https://doi.org/10.3390/f12101335