Genetic variation analysis on oleoresin yield and growth traits of Pinus elliottii open-pollinated families

Objective  Growth property, wood property and oleoresin trait are target traits in the new round of slash pine (Pinus elliottii ) genetic improvement. The goal was to analyze phenotypic performance, heritabilities and trait correlations of tree height, diameter at breast height (DBH), individual volume and resin mass, and provide a theoretical basis for developing breeding strategies for multiple traits.

Method  Thirty-two open-pollinated families of 18-year-old P.elliottii in Taishan City of Guangdong Province were tested. Resin samples at breast height were collected for 24 hours, the mass was determined and the amount of growth was measured. The trait heritabilities and correlations between traits were estimated using Asreml.

Result  The resin mass (m) presented positively skewed distribution, and its coefficient of variation was higher than those of the growth traits, reaching 75.04%. The individual narrow-sense heritability and family average heritability for transformed resin mass (m_t) were 0.216 1 and 0.600 5. The narrow-sense heritabilities for growth traits ranged from 0.252 7 to 0.415 1, and the family average heritabilities ranged from 0.648 3 to 0.751 2. The genetic correlations among tree height, DBH and individual tree volume were strong with the correlation coefficients from 0.813 to 0.983(P＜0.001), and their genetic correlations with wood density were medium and significantly positive(P＜0.05), while the standard errors were large. No significant correlation was found between resin mass and the above traits.

Conclusion  To select individual performing well in oleoresin and wood properties, it is reliable to combine family selection and within-family selection. It’s possible to simultaneously improve growth, wood density and resin mass using current genetic materials of P. elliottii.