Variance analyses of growth and wood characteristics of 50 Pinus koraiensis clones

In order to obtain Pinus koraiensis resources with high yield and excellent quality, we took 50 P. koraiensis clones in the Kaishantun Forest Farm in Longjing City, Jilin Province as materials, and investigated their growth characteristics (tree height, diameter at breast height, volume) and wood properties (basic density, lignin, hemicellulose, cellulose, holocellulose, carbon content, fiber length, fiber width). Variance analysis showed that all the traits were significantly different (P<0.01) among different clones except for lignin content (P=0.114). The coefficients of phenotypic variation of all the traits ranged from 5.09% to 34.48%. The repeatabilities of different traits ranged from 0.5234 to 0.8481 except for lignin content (0.2689), showing its high repeatability. High variation and repeatability values were beneficial to evaluation and selection of excellent clone. Correlation analysis results showed that there existed significantly positive correlations between tree height, diameter at breast height and volume (r>0.787). There also existed significant correlation among lignin, cellulose, hemicellulose and holocellulose, and a significantly positive correlation was also found between fiber length and fiber width (r>0.549). Using the method of multiple-traits evaluation, the growth traits of the clones were evaluated with a selection rate of 10%, and PK6, PK47, PK15, PK37 and PK27 were selected as excellent clones. The tree height, diameter at breast height, volume of these excellent clones were higher than the total average by 8.50%, 19.05% and 50.00%, and the genetic gains were 4.47%, 12.91% and 30.92%, respectively. When the clones were evaluated by wood traits with a selection rate of 10%, PK22, PK20, PK41, PK18, PK21 were selected as excellent clones, and the genetic gains of these clones ranged from 0.90% to 31.18%. Due to the weak correlation coefficients between growth characteristics and wood properties, excellent clones were evaluated by growth traits and wood properties independently and the selected clones showed higher potential of improvement. Our research provides a new insight for into selection of excellent clones of P. koraiensis.