Abstract:In order to understand the effect of shading on growth and quality of Callicarpa nudiflora seedlings, the photosynthetic characteristics, chlorophyll fluorescence parameter, the content of chlorophyll and total flavonoid of two-year-old seedlings were studied under different shading treatments, including shading 30%, 50%, 70% and 0%, respectively. The results showed that the diurnal variation curve of net photosynthetic rate (Pn) of C. nudiflora was bimodal type under 0% and 30% shading, and with the increment of shading, diurnal variation curve of Pn was from bimodal into unimodal type gradually. The transpiration rate (Tr) and stomatal conductance (Gs) were unimodal type, and the peak value also gradually decreased with the increment of shading. The diurnal changes in PSⅡ maximal efficiency (Fv/Fm) and potential efficiency (Fv/Fo) showed ‘V’ type, those average value under shading treatments were significantly higher than those under 0% shading, and significantly increased (P < 0.05) with the increment of shade. The contents of chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid (Car) in the leaves significantly increased with the increment of shading (P < 0.05), but the Chl a/b and Car/Chl decreased with the increment of shading, the content of total flavonoids in the leaves increased at first and then decreased, and reached up to maximum under shade of 30%. Therefore, from the photosynthetic characteristics, C. nudiflora seedling would be suitable for growth under 0% shade, but in order to gain high flavonoids, it would be a good choice under 30% shading.
