Objective This paper studies the effects of colchicine solution mass concentration, treatment time and pre-culture time on the induction of polyploidof ‘Jingzao 39’ in vitro, optimizes the proliferation and rooting medium of ‘Jingzao 39’, and an in vitro polyploid induction system for ‘Jingzao 39’ was established and polyploid plants were obtained.

Method Using randomized complete block design, we investigated the effects of different mass concentrations of colchicine solution and treatment time combinations on adventitious bud regeneration of ‘Jingzao 39’, the effects of different pre-culture time on polyploid induction of ‘Jingzao 39’ in vitro, the effects of different growth regulator combinations on the proliferation culture of ‘Jingzao 39’ and the effects of different basic media and growth regulator combinations on the rooting culture of ‘Jingzao 39’.

Result (1) When the mass concentration of colchicine solution was 80 mg/L and treated for 48 h, the survival rate of ‘Jingzao 39’ leaves was (50.00 ± 7.07)%, and the differentiation coefficient was (2.06 ± 0.17). (2) The best pre-culture time was 6 d, and the tetraploid ‘Jingzao 39’ was obtained with 80 mg/L colchicine and treatment for 48 h. (3) The optimal proliferation medium was MS + 0.8 mg/L 6-BA + 0.4 mg/L IBA + 30 g/L maltose, pH = 5.8, and the average proliferation coefficient was (4.22 ± 0.22). (4) The best rooting medium was modified 1/2MS + 0.8 mg/L IBA + 30 g/L maltose, pH = 5.8, and the average root length was (5.22 ± 0.19) cm, and the average rooting number was (3.20 ± 0.22).

Conclusion The polyploid induction system of ‘Jingzao 39’ is established preliminarily, and one polyploid ‘Jingzao 39’ is obtained. The methods of its proliferation and rooting culture are optimized. It provides a feasible technical method for the germplasm innovation of fine jujube variety ‘Jingzao 39’, and provides an experimental basis for the application of polyploid induction in jujube and other fruit trees.