Objective Substrate for rapid propagating Liupao tea strains using plant cuttings was explored.

Method Cuttings with short spikes from four Liupao tea strains, i.e., Wucha 12, Wucha 16, Wucha 17, and Wucha 18, were cultured on loess (CK) and volumetric mixtures of loess∶sawdust at a ratio of 2∶1 (T1), peat soil∶perlite at 5∶1 (T2) or peat soil∶perlite∶sawdust at 4∶1∶2 (T3). Rates of callus formation, rooting, survival, and qualified plant count of the explants in the propagation experiment were determined.

Results Significant impacts on the physiological indicators of the cuttings cultured on the substrates were observed. Thirty days after start of cultivation, CK produced the greatest rate on callus formation among the various substrates. However, in 40-60 d, the rate became significantly higher with T1 and T2 (P＜0.05). By the time of 70-80 d of cultivation, the lowest rate was found on the cuttings grown on CK. On rooting, the cuttings showed the highest rate on T1 by the 90^th day, and Wucha 12 explants cultured on all mixture substrates had a perfect rating of 100%. In 260 d, the survival rate and qualification rate of the propagated plants cultivated on the 3 mixture substrates were significantly higher than the control treatment (at P＜0.01), and the number of leaves was higher than those on CK.

Conclusion Among the tested Liupao tea strains and culture substrates, T2, which applied a mixture of peat soil and perlite in a volumetric ratio of 5∶1, as a substrate for cultivating Wucha 12 explants rendered the highest rates of rooting at 100%, survival at 90.67%, and 83.33% plants qualified for transplantation. It was recommended for the cutting propagation program.