Effect of Fertilization On Physiological Activity of Sloanea Hemsleyana (T. Ito) Rehd. Et Wilson Seedlings

Sloanea hemsleyana (T. Itô) Rehd. et Wilson (fangli) is an evergreen tree in Elaeocarpaceae. It can be planted as an ornamental plant for its lush green foliage and bio-energy plant for its high oil content seeds. To produce this plant commercially, seeds were collected from an elite population in Zhangjiajie National Forest Park (Hunan, China) and germinated in outdoor conditions. When seedlings were 30cm high, they were transplanted into 400 ml plastic containers with perlite and peat moss mix and fertilized with N, P and K (200, 500, 1000 mg, respectively) at nine combined concentrations. The chlorophyll content increased significantly as the nitrogen concentration went up. However, both high doses of phosophrous and potassium reduced the chlorophyll conetnt. Under the treatments of 500mg-N+200mg-P+500mg-K and 1000mg-N+500mg-P+200mg-K, chlorophyll content increased 204% and 196% compared to the control at 0.99mg/g. Fertilization could also stimulate the activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT). The highest activity of SOD was produced also under the treatment of 500mg-N+200mg-P+500mg-K, which was 96.6% higher than that of the control (83.5U/g.FW.min). For POD and CAT activities, the highest values were under the treatment of 1000mg-N+500mg-P+200mg-K that were 27.61% and 167% higher than that of the control, respectively. The content of malonyl dialdehyde (MDA) decreased under all fertilizer treatments and the lowest value was under the treatment of 500mg-N+200mg-P+500mg-K, which was 15.84% lower than that of the control. Fertilization can promote the growth of fangli seedlings and the recommended application is 1000mg-N+500mg-P+200mg-K for every 45 days.