[Effects of color films shading on Phellodendron amurense seedlings biomass and primary nitrogen-assimilation enzyme activities].

In this paper, greenhouse Phellodendron amurense seedlings were shaded with red, yellow, blue, and green films for 100 days, and their biomass, chlorophyll and soluble protein contents, and nitrate reductase and glutamine synthetase activities were determined. Compared with exposure under sunlight, color films shading decreased the seedlings biomass significantly. Plant height and stem diameter had the similar trend with plant biomass. Root/ shoot ratio was less affected by red and yellow films shading, while root biomass was decreased significantly under blue and green films shading. Leaf chlorophyll content was increased significantly under the shading with blue, green and red films, especially with blue film. Red film shading increased the chlorophyll a/b ratio, while blue film shading was in adverse. Under color films shading, soluble protein content and nitrate reductase and glutamine synthetase activities were significantly higher than the control.

[Effects of water stress on protective enzyme activities and lipid peroxidation in Phellodendron amurense seedlings].

This paper studied the effects of water stress on the dynamic variations of malondialdehyde (MDA) and free proline contents, and of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities in Phellodendron amurense seedlings. The results showed that after treated with light drought, heavy drought and waterlogging for 40 days, the MDA content in corktree seedlings was significantly higher, being 2.49, 2.37 and 4.12 times of the control, respectively, but after treated for 80 days, there was no significant difference among the three treatments. The free proline content had no obvious variation under waterlogging and in the control, but increased after 40 days of light and heavy drought while declined after 80 days of drought stresses, with the increment being higher under heavy drought than under light drought. No regularity was found for the dynamic variations of SOD, POD and CAT activities, but they were significantly higher under heavy drought than under light drought, waterlogging, and the control.