Shoot organogenesis and somatic embryogenesis from leaf and root explants of Scaevolasericea

Hanzhi Liang,Yuan Li,Jaime A Teixeira Da Silva,Songjun Zeng,Guohua Ma,Kunlin Wu,Hai Ren,Youhua Xiong,Xinhua Zhang,Shuguang Jian,Haifeng Yan,Feng Zheng,Yuping Xiong,Beiyi Guo

doi:10.1038/s41598-020-68084-1

Abstract

An efficient regeneration system via shoot organogenesis and somatic embryogenesis from in vitro leaf and root explants was established for Scaevola sericea for the first time. The highest axillary shoot proliferation coefficient (4.8) was obtained on Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 6-benzyladenine (BA) and 0.1 mg/L α-naphthaleneacetic acid (NAA) every 45 days. Young in vitro leaves and roots, which were used as explants, were cultured onto medium supplemented with different plant growth regulators. Our results showed that only cytokinins BA and thidiazuron (TDZ), could induce adventitious shoots and somatic embryos from leaf and root explants. The optimal medium to achieve this was MS medium supplemented with 2.5 mg/L BA and which induced most adventitious shoots (2.7) and somatic embryos (17.3) from leaf explants within 30 days. From root explants, 1.1 adventitious shoots and 7.6 somatic embryos could be induced on MS medium supplemented with 2.5 mg/L TDZ. Histological observation showed that both somatic embryos and adventitious shoots were originated from homogeneous parenchyma and the development of somatic embryos was visible. Maximum rooting percentage (99.0%) was achieved on half-strength MS medium supplemented with 2.5 mg/L NAA. Well-rooted plantlets, which were transplanted into a substrate of pure river sand, displayed a high survival percentage of 91.7% after transplanting for 45 days while the best substrate for plantlet growth was river sand: coral sand (1:1).

Highlights

An efficient regeneration system via shoot organogenesis and somatic embryogenesis from in vitro leaf and root explants was established for Scaevola sericea for the first time
The highest proliferation coefficient was 4.8 with 1.0 mg/L BA + 0.1 mg/L naphthaleneacetic acid (NAA), which was insignificantly different to the use of BA alone in Murashige and Skoog (MS) medium at 1.5 mg/L, giving a proliferation coefficient of 4.4 (Fig. 1a)
When leaf explants were light cultured on medium containing 0.5–2.5 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) for 30 days, they became swollen and induced yellow friable callus (Fig. 1b), but on medium with 0.5–2.5 mg/L α-naphthaleneacetic acid (NAA) for the same period, some callus was induced at the cut section

Summary

Introduction

An efficient regeneration system via shoot organogenesis and somatic embryogenesis from in vitro leaf and root explants was established for Scaevola sericea for the first time. Young in vitro leaves and roots, which were used as explants, were cultured onto medium supplemented with different plant growth regulators. Our results showed that only cytokinins BA and thidiazuron (TDZ), could induce adventitious shoots and somatic embryos from leaf and root explants. The optimal medium to achieve this was MS medium supplemented with 2.5 mg/L BA and which induced most adventitious shoots (2.7) and somatic embryos (17.3) from leaf explants within 30 days. 1.1 adventitious shoots and 7.6 somatic embryos could be induced on MS medium supplemented with 2.5 mg/L TDZ. An efficient regeneration system via shoot organogenesis and somatic embryogenesis from in vitro leaves and root explants was established in S. sericea for the first time

Methods

Results

Discussion

Conclusion