Abstract:

Objective: Linalool is the flavor with the widest uses and the largest consumption in the present world. Artificial cultivation of Cinnamomum camphora var. linaloolifera in dwarf form is an important way to solve the shortage of raw materials for extraction of essential oil. To reveal the dynamic changes of the contents of essential oil and nutrient in branches and leaves in the growing season and their correlation is of great significance for the establishment of high yield and high efficiency nutrient management and cultivation model of dwarf forest. Method: Dynamic changes of essential oil content and nitrogen, phosphorus and potassium in leaves and branches were measured for 3 clones in different months and ANOVA and correlation analysis were conducted to detect the patterns of accumulation of essential oil and nutrients and their dynamic relation. Result: 1) The content of leaf essential oil of C. camphora var. linaloolifera showed a bimodal curve, which peaked in May and August, and the difference between maximum and minimum values was more than 45%. However, the content of essential oil in branches showed a "V" type change, with a low content in the period of vigorous growth. The difference between the maximum value and the minimum value is more than 35%. The content of essential oil was significantly larger in leaves than in branches, and the fluctuation range of leaf/branch ratio of essential oil was 4.74 to 15.33. The changes of essential oil content in leaves and branches were significant among different clones. 2) As the growth process progresses, the change of total nitrogen content in growing season showed a "W" pattern in leaves and a "V" pattern in branches. All reached the lowest value in July or August. The fluctuation range of total nitrogen content in leaves and branches was 1.56 to 3.84; The total phosphorus content of leaves was similar to that of total nitrogen for a "W" pattern, which reached the minimum value in May or July. The content of total phosphorus in branches increased gradually. The change of total potassium content in leaves showed an inverted "V" pattern, reaching the maximum in June or August. While the change of total potassium content in branches showed a "W" pattern, reaching the lowest value in May or July. The contents of nitrogen, phosphorus and potassium in C. camphora var. linaloolifera was larger in leaves than in branches, and the contents of nitrogen, phosphorus and potassium in branches and leaves were nitrogen > potassium > phosphorus. Changes of nitrogen, phosphorus and potassium content in different clones in different months reached a significant level (P < 0.05). The correlation of nitrogen, phosphorus and potassium content in each organ reached a significant or very significant level. 3) In different months of growing season, the nitrogen, phosphorus and potassium in leaves and branches showed different degrees of synergistic or antagonistic relationship with the content of essential oil. There was a negative correlation between leaf essential oil content and nutrients in leaves of C. camphora var. linaloolifera, and the correlation between total nitrogen content and essential oil content reached a very significant level. There was a positive correlation between branch essential oil content and nutrient content in branches, but the correlation was not significant. Conclusion: The essential oil content in leaves of C. camphora var. linaloolifera was relatively high in the period of vigorous growth, while the essential oil content of branches showed an opposite trend. The nutrient content was lower in the vigorous growth period and higher in the late growth period. In order to further explore the formation mechanism of essential oil, comprehensive effects of variety, growth month and nutrients should be taken into account.

Key words: Cinnamomum camphora var. linaloolifera, clones, essential oil content, nitrogen, phosphorus and potassium, dynamic change, correlation