Analysis of Stage Test and Height Selection of Open-pollinated Pinus tabulaeformis Family

In order to estimate the differences among Pinus tabulaeformis families and to select elite family, 82 P. tabulaeformis families with the age of 22 were used to analysis the genetic variation of their growth traits, including the genetic correlation, the phenotype correlation, the genetic variance and environmental variance, the genetic variation coefficient and phenotype variation coefficient, and the heritability. The estimation parameters of early selection were the height and diameters at breast height (DBH). The height of trees was measured at the 5-10th year and the 22nd year, while the DBH was measured at the 22nd year. The results showed that increments of height and volume were very different among P. tabulaeformis families. Integrated with selection efficiency, accuracy percentage and mistake percentage, family selection of P. tabulaeformis might be carried out at the early stage; the first selection should be at the 9th year. In addition, on the basis of volume breeding value, twenty four families were selected at the 22nd year, whose actual gains of volume were 36.54%, 8.92% and 18.63% higher compared with 3 controls respectively. Total 61 individuals derived from 25 families were selected as the second-generation elite trees by combined selection, and the expected genetic gains of progeny test stands were 57.74%, 25.81% and 37.03%, respectively. The selected elite families and trees were superior breeding materials of P. tabulaeformis for plantation establishment on a large scale.