Effects of Plant Growth Regulators on Storage and Hydroponic Flowering of Curcuma kwangsiensis var. nanlingensis Rhizome

【Objective】A comparison of the effects of different plant growth regulators on the storage and hydroponic flowering of Curcuma kwangsiensis var. nanlingensis rhizome was conducted.【Method】The rhizome of C. kwangsiensis var. nanlingensis was soaked in different concentrations of TDZ, 6-BA, GA3 and IAA solutions for 2 h, and stored at 13℃ for 5 months. The physiological indexes were measured and the effects of different treatments on long-term storage of rhizome were compared. In addition, the rhizome of C. kwangsiensis var. nanlingensis was stored at 13℃ for 30 days and then taken out. Germination accelerating was conducted at 30℃ for at least 30 days.When the buds grew to 2 cm, different concentrations of 6-BA and GA3 solutions were used for culturing and the early flowering time and other indexes of rhizome were observed. The effects of two plant growth regulators on the hydroponic flowering of rhizome of C. kwangsiensis var. nanlingensis were compared.【Result】During the storage, moisture and protein content of rhizome decreased continuously, accompanied by a constant increase in conductivity. Different concentrations of TDZ and IAA could reduce the decrease of rhizome moisture content, while 10 mg/L IAA treatment retarded the reduction of protein content of rhizome most significantly. On the 150th day of rhizome storage, the conductivity of 10 mg/L IAA treatment group was 74 % of the control group, indicating that the longterm storage effect of rhizome of C. kwangsiensis var. nanlingensis soaked with 10 mg/L IAA was the best. Both 6-BA and GA3 could improve the flowering quality of C. kwangsiensis var. nanlingensis. Compared with the control group, 6-BA treatment could advance the flowering time. Low concentration of GA3 treatment had a significant effect on flower branch length elongation while high concentration of GA3 treatment not only delayed flowering time but also reduced flower branch length and flower branch diameter.【Conclusion】Plant growth regulator could protect the long-term storage of rhizome of C. kwangsiensis var. nanlingensis and improve the flowering quality during hydroponics. The protective effect of 10 mg/L IAA soaking on long-term storage was the best, and 5 mg/L 6-BA aqueous solution had the best effect on early flowering and growth of flower branches.