Effect of the Selection of Grown Structure and Growth Characteristics on the Improvement of Tree Trunk Form in Paulownia fortunei

To improve the tree trunk form of Paulownia fortunei,the genetic,pheno-type and environment correlation between tree crown,growth characteristics,stem form in P. fortunei were analyzed on the basis of quantitative genetics,their direct and indirect path-coefficients.The results show that the determination coefficient of the characteristics ofgrowth and tree crown to stem form in P.fortunei is higher in diameter,amount of thinbranches total length of branches, surface area of tree crown and tree height.he advantageof genetics and relative efficiency of selecting index of single character of stem form is smallerthan the that of directly selected.Selecting indexes of multishare characters is better thanthat of the single character. Genetic advantages and relative efficiency of selecting index thatwas made up of a number of thin branch,diameter, total length of branches,surface area oftree crown and tree height is best in the 61 selecting indexes. GS and RGS of comprehensiveselecting index of fullness and trunk form is 0.155,159.0157% and 0.174,128.3679% respectively.It is effective to use multishare comprehensive selecting index for tree valuationand selection the stem form improvement of Paulownia clones.