Establishment of an efficient regeneration system of ‘ZiKui’ tea with hypocotyl as explants

Abstract

Abstract Zikui (Camellia sinensis cv. Zikui) is a recently discovered cultivar of local purple tea in Guizhou, China and it is a perennial woody plant, mainly propagated by cuttings. It is also a model plant for the study of anthocyanins,but the limited germplasm resources and the limitation of traditional reproduction seriously hinder its application. Here, an efficient regeneration system is established by using hypocotyl as explants for the first time. Different plant growth regulators (PGRs) were evaluated during different regeneration processes including callus and root induction. According to our findings, using the optimal disinfection conditions, the embryo contamination rate was 17.58 %. Additionally, the mortality rate was 9.69 %, while the survival rate was measured as 72.73 %. Moreover, the highest germination rate of 93.64% was observed under MS+2.40 mg/L GA3 medium conditions. The optimal callus induction rate was 95.19 %, while the optimal adventitious bud differentiation rate was 20.74%, Medium with 1.6mg L−1 IBA achieved 68.6% rooting of the adventitious shoots.The survival rate was more than 65% after 6 days growth in the cultivated matrix. In summary, our research aims to establish a regeneration system for Zikui tea plants and design a transformation system for tea plant tissue seedlings. This will enable the transfer of the target gene and ultimately facilitate the cultivation of new tea varieties with unique characteristics.