Achievements in Selecting for the Second Generation Elite Tree of Picea crassifolia kom. passed appraised by specialists recently. The specialists considered that, the project builded two open-pollinated progeny test forests through culturing the seedlings whose seeds comes from the first generation seed orchard and other provenances of Picea crassifolia. After 14 years of cultivation, observation and research, the genetic variation of growth traits of 121 Picea crassifolia families including 4846 individuals from two open-pollinated progeny test forests were analyzed to select the second generation elite trees for the second generation orchard in Qinghai Province. The results showed there was significant difference in growth traits among different families, the range of phenotypic variation coefficient were 15.56%~65.71%. Family, block, year, and the interaction effects between family and year significantly affected seedlings growth. Individual and family heritability of height ranged from 0.015-0.113, 0.301-0.858, respectively. Family heritability was higher than individual heritability. For index selection with linear combination of growth and resistance traits, 18 Picea crassifolia families were selected as superior familes by the selection rate of 15%, the expected genetic gain was 4.25%. Individual breeding values were predicted by using the best linear prediction approach. Comparison between combined selection and family/within-family selection showed that the second generation elite tree populations that were established by combined selection had a higher genetic diversity than that established by family/within-family selection, but the two selection methods got nearly common expected genetic gains. In terms integration of high genetic gain and genetic diversity, elite trees chosen by combined selection were more suitable to establish the advanced-generation seed orchard. As a result, total 206 superior individuals were selected as the second generation elite trees by combined selection; and the expected genetic gains was 20.10%-44.23%. This provides the higher quality breeding materials for high generation improvement of Picea crassifolia.
The experts suggest that it is necessary for further increasing breeding scale and deepening the resistance study in super families of Picea crassifolia. This project was completed together by State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry in Chinese Academy of Forestry and Dongxia Forestry Centre of Datong County.