An efficient method for immature embryo rescue and plant regeneration from the Calli of Ziziphus jujuba ‘Lengbaiyu’

ABSTRACT

Hybrid breeding of Chinese jujube (Ziziphus jujube) is limited by embryo abortion. Improving the success of embryogenic progeny and immature embryo culture techniques could increase the breeding efficiency of new jujube varieties. We optimised the current immature embryo culture techniques by using immature embryos before the globular stage of Chinese jujube variety Lengbaiyu. The optimal growth media were as follows: for 30-day-old immature embryo growth, MS + IBA 0.8 mg·L⁻¹ + ZT 0.5 mg·L⁻¹ + GA₃ 7.0 mg·L⁻¹ + NAA 0.2 mg·L⁻¹ + LH 0.5 mg·L⁻¹ + 5% sucrose, with 22.22% embryonic growth rate and 0.41% plantlet formation rate; and for young embryo differentiation, MS + TDZ (0.8 mg·L⁻¹) + IAA (0.5 mg·L⁻¹) + sucrose (3%), with 81.12% differentiation rate. Thus, regeneration via callus induction effectively improved the efficiency of embryo rescue from young immature embryos in Lengbaiyu, which might provide new approaches for breeding Chinese jujube.

KEYWORDS:

• culture technique
• immature embryo rescue
• callus culture
• seedlings
• Chinese jujube

List of reagent abbreviations

Abbreviation	=	Reagent name
2,4-D	=	2,4-Dichlorophenoxyacetic acid
6-BA	=	6-Benzylaminopurine
GA3	=	Gibberellic acid
IBA	=	Indole-3-butyric acid
IAA	=	Indole-3-acetic acid
KT	=	6-Furfurylamino-purine (Kinetin)
LH	=	Hydrolysed milk protein
MS	=	Murashige and Skoog medium
1/2MS	=	Medium containing half-strength Murashige and Skoog micro- and macronutrients
NAA	=	1-Naphthaleneacetic acid
TDZ	=	Thidiazuron
ZT	=	Zeatin

Acknowledgements

This work was supported by the National Key Technology R&D Program from the Ministry of Science and Technology of China (2013BAD14B030101); the Scientific Research Fund for Returned Scholars by the Office of Overseas Study of Shanxi Province (2012-103); the Grant for Conservation of Crop Germplasm Resources by the Ministry of Agriculture of China (NB2014-2130135-02); support to the Key Research Team of Genetic Improvement and Utilisation of Jujube Resource; and support to Shanxi Provincial Key Laboratory of Genetic Improvement and Utilisation of Pomological Germplasm.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the the Grant for Conservation of Crop Germplasm Resources by the Ministry of Agriculture of China [NB2014-2130135-02]; the Scientific Research Fund for Returned Scholars by the Office of Overseas Study of Shanxi Province [2012-103]; the National Key Technology R&D Program from the Ministry of Science and Technology of China [2013BAD14B030101].