Study On Nutrient Deficiency And Fertilization Of Calophyllum Inophyllum L. Seedlings

Calophyllum inophyllum L.as the tropical and southern subtropical evergreen arbor, belongs to Guttilerae, Calophyllum L.It is salt-tolerant ,strong wind resistant and its root system is flourishing, therefore can grow in barren coast and low mountains. Calophyllum inophyllum L. is of strong functions of ecological, medicinal and rich of oil.It has a high value for both development and utilization. As far as we know,researches about Calophyllum inophyllum L. were mainly on its morphological and biological characteristics, ecological and medicinal functions and economic values. Researches about the effect of nutrition on seedlings were rarely reported. We tested how the nutrition deficiency and the element in the manurial effect the growing of seedlings,hoping to promote a healthy and rapid way for the development of Calophyllum inophyllum L. plantation. In the research of main nutrient elements deficiency,we got our data by survey and the analysis of photosynthetic pigments and leaf nutrient.In the research of the effect of elements in manurial, we analyzed photosynthetic pigments , photosynthetic parameters and physiological changes under different fertilization levels, after these analysis,we determined the optimum fertilization by the method of critical concentration.1.The growth characteristics and element deficiency disease of Calophyllum inophyllum L. seedlings were studied in greenhouse by hydroponics, seven treatments were complete nutrient mixyure(CK), minus nitrogen(-N), minus phosphorus(-P), minus potassium(-K), minus calcium(-Ca), minus magnesium(-Mg) and minus sulfur(-S). The results showed that: The foliar symptoms of (-N), (-K) and (-S) were most apparent, the leaf became yellow and discoloration, at last some of the leaves werer necrosis; Compared with the CK,the seedling height,ground diameter,laef area and biomass of Calophyllum inophyllum L. seedlings of the minus nutrition elements showed significant decreases, the shoot ratio of no-N, no-K and no-S was increased compared with CK;The chlorophyll content of no-N and no-S showed significant decreases compared with CK, but other treatments were no significant difference; There was definite synergism or antagonism between different nutrients in seedling leaves under diffrerent treatments of nutrient deficiency.2. The nitrogen fertilization experiment of Calophyllum inophyllum L. seedlings under different levels(0,50,100,150,200,300,400,600 mg?seedling -1) were studied in greenhouse through exponential fertilization. The results showed that: seedling height, ground diameter, laef area and biomass of Calophyllum inophyllum L. seedlings increased as the nitrogen fertilization increased from 0 to 200 mg?seedling-1 and then decreased with the nitrogen fertilization increased from 200 to 600 mg?seedling-1. The underground biomass was not significantly differed, the shoot ratio decreased as the nitrogen fertilization increased; Chlorophyll a, chlorophyll b and total chlorophyll increased while photosynthetic gas exchange parameters showed the trend first increased and then decreased as the nitrogen fertilization increased, variance analysis indicated that they were reached significant difference; The MDA and free proline content showed the trend first decreased and then increased while the SOD activity showed first increased and then decreased as the nitrogen fertilization increased; The leaf N concentration kept on increasing as the nitrogen fertilization increased; Based on critical concentration method, the critical values of N, P and N/P were 9.04mg/g, 0.48mg/g and 17.19, the optimal concentration and ratio range were 9.04～17.04 mg/g, 0.48～0.73mg/g and 17.19～23.74, it could be inferred that 200～400 mg·seedling-1 was the optimal nitrogen amount for Calophyllum inophyllum L. seedlings.3.The phosphor fertilization experiment of Calophyllum inophyllum L. seedlings under different levels((0CK),7.5,15,22.5,30,40,60,90 mg?seedling-1) were studied in greenhouse. The results showed that: seedling height, laef area and biomass of Calophyllum inophyllum L. seedlings increased as the phosphorus fertilization increased from 0 to 30 mg?seedling-1 and then decreased with the phosphorus fertilization increased from 30 to 90 mg?seedling-1, while the ground diameter and shoot ratio had no significant variety; The chlorophyll a content had no significant variety under different phosphorus levels, chlorophyll b and total chlorophyll showed the trend first increased and then decreased as the phosphorus fertilization increased;The MDA content showed the trend first decreased and then increased as the nitrogen fertilization increased. The free proline decreased as the phosphorus fertilization increased from P1 to P3, then had no ignificant variety. The SOD activity showed increased as the phosphorus fertilization increased from P1 to P3, then kept steady, but decreased significantly at P8;The leaf P concentration kept on increasing as the phosphorus fertilization increased; Based on critical concentration method, the critical values of N, P and N/P were 9.09mg/g, 0.47mg/g and 19.84, the optimal concentration and ratio range were 9.09～16.28 mg/g, 0.47～0.75mg/g and 19.84～23.33, it could be inferred that 30～60 mg·seedling-1 was the optimal phosphorus amount for Calophyllum inophyllum L. seedlings.