Abstract: A tissue culture experiment was conducted to investigate the changes of the growth, physiological characteristics and curcumin concentration of in vitro Curcuma aromatica plantlets under salt stress (0, 25, 50, 75, 100, 125 or 150 mmol·L^-1 of NaCl). Results showed that the concentrations of proline and malondialdedyde (MDA) of in vitro C. aromatica plantlets increased, while the concentrations of chlorophyll and carotenoid and the activities of superoxide dismutase (SOD) and catalase (CAT) decreased significantly under salt stress. No significant differences in the basal diameter, height and fresh weight were observed between the 25 mmol·L^-1 NaCl and control treatments, while those significantly decreased under over 50 mmol·L^-1 NaCl, suggesting that the plantlets of C. aromatica could tolerate 25-50 mmol·L^-1 NaCl stress. With the stress increasing, the soluble sugar concentration and peroxidase (POD) activity in C. aromatica increased in the early phase of stress and decreased subsequently, and the maximum was present under 75 mmol·L^-1 NaCl stress. The phenylalanine ammonia lyase (PAL) activity and curcumin concentration in leaves significantly improved under 50-100 mmol·L^-1 NaCl treatment, indicating that this salt stress promoted the formation of curcumin. Therefore, the range of 25-50 mmol·L^-1 NaCl benefits the growth of C. aromatica plantlets, while the 75 mmol·L^-1 NaCl increases the curcumin concentration significantly.

Key words: wheat, water characteristics, grain yield, water use efficiency., micro-sprinkling hose length and width, chlorophyll fluorescence-characteristics