Analysis on Physiological and Ecological Characteristics and Contents of Essential Oil in Different Superior Plants of Dextral Linalool-type Cinnamomum camphor

In order to provide references for the cultivation, development and utilization of the improved varieties of dextral linalool-type Cinnamomum camphor, the cuttage was conducted on the 11 superior plants of dextral linalool-type Cinnamomum camphor (including 122, 129, 250, 251, 265, 266, 280, 281, 282, 283, 294 superior plant) in Jinxi County of Jiangxi Province. Then, their morphological indexes (such as the plant height, crown width, basal diameter, and biomass), leaf phenotypic characters (such as the leaf length, leaf width, leaf index, leaf area, and leaf perimeter), physiological indexes (such as the contents of chlorophyll a and chlorophyll b, soluble sugar content, and soluble protein content) and the content of essential oil were measured. The differences and correlations of the indexes were also analyzed. Last, the principal component analysis method was used to screen the excellent superior plants. The results showed that: there were significant differences in the plant height, basal diameter, crown width and aboveground biomass among the 11 superior plants (P＜0.05). Among the leaf phenotypic indexes, the variation degree of leaf area was the largest, the leaf length of 251 superior plant was the largest, and the leaf index of 283 superior plant was the largest. There were significant differences in the contents of total chlorophyll and soluble sugar among the superior plants, but no significant difference in the protein content. The total chlorophyll content and soluble protein content of 281 superior plant were the highest, which were 5.19 mg·L⁻¹ and 0.21 mg·g⁻¹, respectively, while the content of soluble sugar of 283 superior plant was the highest, being 18.38 mg·g⁻¹. There were great differences in the oil yield among the superior plants, and the oil yield of 122 superior plant was the highest (being 2.49%). The leaf length and leaf width were positively correlated with the leaf area and leaf perimeter, while the content of soluble protein was significantly negatively correlated with the content of leaf essential oil. The superior plants were divided into 4 categories by cluster analysis. The principal component analysis showed that the comprehensive score of 251 superior plant was the highest, and the comprehensive performance of 251 and 280 superior plants was better. According to the results of principal component analysis and quality evaluation of superior plants, 251 and 280 superior plants could be used as the excellent varieties of dextral linalool-type Cinnamomum camphor cultivated in Jinxi County.