The Effects Of Fertilizer And Plant Growth Regulators On Growth And Cold-resistant Of Cornus Officinalis Seedling

Cornus officinalis Sieb. et Zucc. is one of the most important medicinal plants in China and it also possesses significant value in ecology and economy. However, the Cornus officinalis seedling would undergo different stress conditions in the process of introduction and cultivation. So it is important to enhance the seedling resistance in order to enlarge the cultivation area and also to rich the tree species resources in introducing regions. Therefore, a potted experiment with one-year old Cornus officinalis seedling introduced from xixia of Henan province was conducted in Beijing. The different levels of nitrogen, phosphorus and potassium, different plant growth regulators in terms of concentration and sprayed time, different plant growth regulators sprayed under different nutrient levels were studied. The optimum combinations were selected depended on the growth (seedling height, seedling diameter, stem dry weight, root dry weight, height to diameter ratio and shoot to root ratio) and cold- resistant physiology (the relative permeability, MDA content, soluble sugar content and pro content) of Cornus officinalis seedling with the methods of principal component analysis, correlation analysis and fuzzy synthetic evaluation. The main results are as follows:The best fertilizer treatment was N₃P₃K₁(nitrogen: 0.3g, phosphorus: 0.6g, potassium: 0.075g), the cold- resistance of Cornus officinalis seedlings were best with the proper seedling height, biggest seedlings diameter, the highest content of the relative conductivity and MDA, the lowest content of the soluble sugar and proline in Cornus officinalis shoot under this nutrient level. The results showed that the seedling diameter was an important morphology indicator for reflecting the change of the seedling growth and stress resistant physiology.The best plant growth regulators, concentration and sprayed time were acquired by the plant growth regulators experiment. The mixed compound of PP333 +6-BA(PP333 mixed with 6-BA at ratio of 1:1)sprayed in August with 300 mg·L^-1 had the best effect of the cold- resistance of Cornus officinalis seedlings.From the experiment on the combined effect of fertilizer and plant growth regulators, the best effect acquired by the mixed compound of PP333 +6-BA(PP333 mixed with 6-BA at ratio of 1:1) sprayed in August was in the concentration of 300 mg·L^-1 and under fertilizer treatment of N3P3K1.