Objective To evaluate the genetic characteristics of open-pollinated families of Picea crassifolia in seed orchard in order to improve the elite breeding of P. crassifolia for afforestation.

Method The genetic variation of height, stem increment, reserving rate at the thirteenth year and freezing injury rate at the eleventh year of open-pollinated P. crassifolia families were analyzed to select elite families using composite index selection method and select superior individuals using breeding value predicting by BLUP for providing high quality genetic breeding materials of P. crassifolia.

Result The results showed that the phenotypic and genetic variation coefficient were 24.06%~84% and 3.28%-19.31% for height, stem increment, reserving rate at the thirteenth year and freezing injury rate at the eleventh year. The family and the interaction effects between family and block significantly affected the height, stem increment of thirteen-years-old P. crassifolia. The family heritabilities of height and stem increment were 42.5% and 34.2% respectively, while, their individual heritability were 3.00%. Their family heritability was higher than individual heritability in P. crassifolia families. 21 elite families were chosen based on diversity and genetic gain using comprehensive index selection method, the realized genetic gain of height, survival rate and freezing injury rate were 5.66%, 12.59% and 12.96%, respectively. According to breeding value, 111 superior individuals were selected from 1103 trees, the expected genetic gain was 20.10%.

Conclusion The growth of P. crassifolia is controlled not only by genetic heritability, but also by the interaction effects between genetic heritability and environment. According to composition index of height and reserving rate at the thirteenth year and the freezing injury rate at the eleventh year, 21 elite families with good growth performance and strong resistance were chose by 35% selection rate, which may be used in reorganization and expansion of seed orchard in the first and 1.5 generation of P. crassifolia.