Genetic Improvement Of Key Wood And Resin Properties Of Pinus Massoniana Lamb

Masson pine {Pinus massoniana Lamb) is one of the most important native tree species in southChina, It plays a key role in providing wood and resin for industiral uses. The area of masson pineplantation has reached up to 40% of total forest area in 17 provinces of south China, but they are mostlysecondary forests with low-yield and low-quality of wood and resin. So, it is of urgency to conductgenetic improvement to generate high-yield and high-quality vaireties for large-scale extension. In thisstudy, the gametes from typical plus trees (gametes of individuals in Pirmary Seed Orchard ) and thefamilies from various-age progeny test plantations were used for measurement of wood properties(including wood density, wood chemical composition and wood tracheid morphology ) and economictrait (resin-yielding capacity) . The data from these expeirments were further used to screen forsuperior genotypes of building-use materials, paper-making mateirals and resin-yielding trees. Theresults were descirbed as below:1.Family variations of wood basic density mainly occurred in the middle annual layer ( 10a-15a)of wood disc. Aged 15 years masson pine wood exhibited a good ratio of wall to cavity and flexibilityfactor of grade II and its diameter annual increment arrived the second growing peak. From the view ofpulp properties and wood production, The reasonable harvesting age of masson pine for pulpwood wasat the 15th year.2.Cellulose content of masson pine showed significant differences between families, withheritability of 0.26. Its association with basic density was significant and the correlation coeiffcient was0.556, which indicates that wood basic density can be the positive predicator for cellulose content ofmasson pine.3.Annual growth ring of masson pine showed signiifcantly positive correlations with 7 ifbermorphology characteristics, including tracheid width, tracheid length, ratio of tracheid length to width,tracheid wall thickness, ratio of wall to cavity, lfexibility factor and rigidity coeiffcient. The associationanalyses suggested that the annual increment of DBH can be an indirect indicator for selection of thepros and cons of paper-making industry.4.The pro-offspring regression analysis showed that the heritability of resin-yielding capacity wasmore than 0.5. The correlation analysis suggested a close relationship between tree factors andgrease-producing capacity. Subsequently, a new method was developed for evaluation ofgrease-producing capacity.5.A total of 110 superior genotype was selected for future uses atfer genetic analyses. Of thesegenotypes, 35 for building wood, 69 for pulpwood and 6 for high resin-yielding. These materials are of significance for Guangxi masson pine seed production.This study systematically analyzed genetic vairations of key wood properties and importanteconomic traits in Masson pine, which established a theoretical basis for the improvement of vairoustraits. The selection and evaluation of pirmary seed orchard pedigree not only laid a solid theoreticalfoundation for thinning of clone seed orchards, but also selected many improved vaireties forbuilding-use, paper-making and resin-yielding industry. Additionally, this study made considerablecontirbutions in effectively saving the genetic resources of Masson pine for future genetic improvement.