Photosynthetic characteristics of Lycoris aurea and monthly dynamics of alkaloid contents in its bulbs

Abstract

The leaf photosynthetic characteristics of Lycoris aurea, the monthly dynamics in lycorine and galantamine contents in its bulb and the correlation among the photosynthetic characteristics and the lycorine and galantamine during the annual growth period were studied by using LI-6400 portable photosynthetic measurement system, high performance liquid chromatography and SPSS13.0 software. The results show that the leaf net photosynthetic rate of L. aurea differs monthly with the maximum of 12.05 μmol m^-2 s^-1 and minimum of 7.07 μmol m^-2 s^-1 in December and April, respectively; the content of both lycorine and galantamine in L. aurea bulbs also alters monthly with maxima of about 0.53 and 0.09 mg g^-1, corresponding to the largest accumulation periods of December and March, respectively; and minimum of 0.21 and 0.03 mg g^-1 in January respectively; and there is a certain correlation between the net photosynthetic rate and lycorine and galantamine contents. The lycorine content in bulbs of L. aurea is higher in winter with lower light illumination and relative humidity. Photosynthesis intensity and environmental factors affect accumulation of lycorine and galantamine in L. aurea bulbs and the optimum harvest seasons of the bulbs for extracting lycorine and galantamine are in December and March, respectively.

Key words: Lycoris aurea, photosynthetic characteristic, lycorine, galantamine, dynamic variation.