Physiological Characteristics Of Dicranopteris Dichotoma Under The Combined Stress Of Light Intensity And Acid Rain

In order to investigate the development mechanism of Dicranopteris dichotoma,which could form a single layer flora under the environmental stress such as light intensity and acid rain,so set up three light intensity gradient(L1 and L2 and L3,the light intensity were 34.82% and 13.18%and 4.69%).The CK was treated with 100% full light irradiation and p H 7.0 as control.Choose the potting controlled test method,pigment content,photosynthetic system and antioxidant enzyme activity were measured.The main conclusions are as following:(1)The contents of total chlorophyll,chlorophyll a,chlorophyll b and carotenoid of Dicranopteris dichotoma under simulated light intensity,acid rain and fertilization treatment has increasing with the decrease of light intensity.(2)The net photosynthetic rate of Dicranopteris dichotoma was significantly higher than that of CK(p< 0.05)under the simulated light intensity,acid rain treatment.The net photosynthetic rate of Dicranopteris dichotoma was the highest under different concentration of acid rain at p H 4.0.The preliminary results showed that the photosynthetic characteristics of Dicranopteris dichotoma were not affected under specific environmental stress(light intensity and acid rain).(3)The Fv/Fm of Dicranopteris dichotoma was significantly higher than that of CK(p< 0.05)under the simulated light intensity and acid rain treatment,but there was no significant change among the treatments.OJIP in all treatments increased significantly under L2 light intensity and reached the maximum value,and decreased under L3 light intensity.(4)The activity of SOD and POD of Dicranopteris dichotoma was significantly lower than that of CK(p< 0.05)under the simulated light intensity and acid rain treatment.(5)The soluble protein content has no regularly change under the simulated light intensity and acid rain treatment,and there was no significant different with CK(p? 0.05).To sum up,weak light is not good for accumulating organic compound,but can increase pigment contents,p H 4.0 acid rain treatment is suitable for.Dicranopteris dichotoma,while full light stress inhibits its growth.Therefore,it initially reveals the adaptability of Dicranopteris dichotoma to light intensity and acid rain,and it has important significance to promote vegetation restoration in low mountain and hilly region of Subtropical Region.