The Research On Growth Traits And Resin Yield Rules Pinus Elliottii Families

Pinus elliottii from the southern United States is one of the most important plantation species for afforestation and resin production. Timber and resin industry plays important roles in promoting the economic development of the southern forest areas in China, increasing financial income, enlarging employment of forestry households, which has become the superior industry and pillar industry in forestry. At present, the need for superior families on high yield of timber and resin is urgent.The experimental forest of Pinus elliottii were studied in this paper on investigation of the growth traits and resin yield rules for three years. Some specific objectives were carried on:(1) the correlation of the average resin yield with growth traits and resin yield ability for 3 years,(2) the annual variation of resin yield and meteorological factors,(3) the test of resin components. This study is dedicated to choose the superior families on specific components of resin and high yield of timber and resin. The results were described as below:1. There were significant differences with height, DBH, volume of timber of Pinus elliottii on different families. Family mean heritability and single-tree heritability for growth traits were high. According to Duncan’s contrast,12,7,15,4,6 were selected for the optimal families whose growths were performed well.2. There were significant differences with resin yield on different families, and there was great potential for selecting the optimal families. The resin output showed a highly significant positive correlations with growths and resin output ability, while the correlations between resin yield ability and growths was not obvious. In various impact factors about resin yield of Pinus elliottii, the resin output ability and DBH were very important factors. Family mean heritability and single-tree heritability for resin yield were high for 3 years. In April, the resin yield of Pinus elliottii families were low, while the resin yield of Pinus elliottii families were high in July. The annual variation of resin yield and temperature had a close relationship. High resin yield showed high temperature. There were significant correlations between resin yield in June, July, August and September with annual resin yield, so the annual resin yield could be forecasted through the resin yield in June, July, August and September which were mainly months on resin yield. According to Duncan’s contrast,7,6,4,12,15 were selected for the optimal families whose resin yield and growths were performed well.3. The resin components were tested, and turpentine accounted for 9.07% of the total resin components. The main components of turpentine were α-pinene and β-pinene. Colophony accounted for 90.93% of the total resin components. The main components of resin levopimaric acid. ANOVA showed that there were significant differences with resin components on different families. Family mean heritability for resin components was high. According to Duncan’s contrast,12,7 were selected for the optimal families whose β-pinene, colophony and isopimaric acid were high.