Effects of shading on photosynthetic characteristics in Paeonia ostii cv.‘Phoenix White’seedlings
The effects of shading treatment at different degrees on photosynthetic characters and the chlorophyll fluorescence parameters in Paeonia ostii cv.‘Phoenix White’(tree peony) seedling were researched in the field.The results showed that under natural full sunshine in summer,the curve of diurnal variation of the net photosynthetic rate was double-peak type with obvious midday depression of photosynthesis,and the net photosynthetic rate was significantly lower than those in the shading treatments.One-year-old seedlings did not found the phenomenon of midday depression under the condition of 75％ shading,and two-year-old seedlings under the condition of 60％ shading had higher level of net photosynthetic rate than the other treatments.Compared with one-year-old seedlings,two-year-old seedlings had significantly higher maximum net photosynthetic rate and apparent quantum yield under natural full sunshine.The values of Fv/Fm of plants in shading treatments were significantly higher than that under full sunshine.The results showed that the seedlings in the field had significant photo inhibition under the conditions of strong light high temperature in the midday of summer,and shading treatment could effectively relieve photo inhibition.It was concluded that 60％ shading was suitable for growth ofP ostii cv.‘Phoenix White’seedlings.
NETL
NSTL
万方数据
维普
