Analysis of genetic effects on a complete diallel cross test of Pinus koraiensis

Thirty-four full-sib Pinus koraiensis families were used to evaluate and identify elite P. koraiensis material. Tree height ( H ) and diameter at breast height (dbh) were assessed. The results from variance analyses showed that familial variance sources for different traits in different growth years were extremely significantly different. The average phenotypic variation coefficients of H , dhb and volume ( V ) among families in different growth years ranged from 7.57 to 15.70, from 10.37 to 12.89 and from 24.44 to 28.13%, respectively. The family heritabilities of all traits ranged from 0.910 to 0.990, which are high values. A significant and positive correlation was observed among all traits, with values ranging from 0.43 to 0.99. According to the analyses of general and special combining ability, female parents F4 and F2 and male parents M7 and M13 had high levels of general combining ability for all three traits evaluated. Families PK05 (F9 × M14) and PK06 (F2 × M14) showed the highest and the lowest specific combining ability values in all traits evaluated. Using the comprehensive multiple-traits method to evaluate the families by traits in the 18th growth year at the rate of < 10%, we selected families PK40, PK05 and PK22 as elite families; the genetic gains for these families in H , dbh and V were 14.43, 11.29 and 24.72%, respectively. This study provides materials and basic theoretical knowledge that can be used to improve seed orchards and develop special hybrid seed orchards.