EFFECTS OF STAND DENSITY ON TURPENTINE TERPENE COMPONENTS AND RESIN DUCT MORPHOLOGICAL STRUCTURE OF PINUS MASSONIANA

The influence of stand density on the resin duct morphological structure and terpene components of Pinus massonianawere studied. The resin duct morphological characteristics and the relative content of the terpene components were investigated by microscopyand gas chromatography-mass spectroscopy, respectively. The experimental results revealed that there was a specific correlation between thestand density andresin duct area, resin duct diameter, and the relative contents of main terpene components in the turpentine extracts. Additionally, the relative contents of β-pinene and (+)-camphene were positively correlated with stand density, with correlation coefficients of 0.8208and 0.5539, respectively.In contrast, the relative contents of(+)-longifolene and (+)-longicyclene were negatively correlated with stand density, with correlation coefficients of -0.5750and -0.7726, respectively, andα-pinene, β-caryophyllene, and (+)-α-longipinene had no correlation with stand density. The relative content of (+)-α-pinene was negatively correlated with the relative contents of both (+)-longifolene and (+)-longicyclene,with correlation coefficients of-0.8770 and -0.8914, respectively. There were positive correlations between the relative contents of (+)-longifolene and (+)-longicyclenewith correlation coefficient of0.9718, (+)-longifolene and (+)-α-longipinenewith correlation coefficient of0.8399,β-caryophyllene and (+)-α-longipinenewith correlation coefficient of0.9360, and (+)-longicyclene and (+)-α-longipinenewith correlation coefficient of0.8626.