Effects of Open and Controlled Pollination and Crown Orientation on the Characteristics of Seeds and Fruits of Picea asperata Mast.

Objective To provide a reference for the precise management and genetic improvement of spruce seed orchards.

Methods In the Shaba National Spruce Germplasm Resources Collection and Conservation Repository,Picea asperata at the fruiting stage (23 years old) was taken as the research object.The mature cones of 30 open-pollinated families, the mature cones on the north and south sides of the crowns of 10 open-pollinated families of Picea asperata, as well as the variation in seed and cone traits of one-to-one interspecific controlled pollination with 6 Picea asperata families as female parents and 6 Picea abies families as male parents and the mature cones of 6 female parents through open pollination were studied.

Results There was no significant difference in the cone traits between the north and south sides of the crowns of P. asperata (P > 0.05).The length, width, length/width of open-pollinated cones and the average weight of seeds produced by cones were significantly 13.20%, 6.64%, 4.36% higher and 1.51 times that of controlled-pollinated cones respectively (P < 0.05). Both open-pollinated and controlled-pollinated cones had rich genetic variation. Among them, the coefficient of variation of the average weight of seeds produced by cones was the highest, which was 38.71% and 37.80% respectively. The coefficients of variation of cone length, width, length/width, average weight of seeds produced by cones and seed yield rate of 30 open-pollinated families were 14.74%, 12.14%, 12.61%, 14.74%, and 12.56%, respectively. The coefficients of variation of the seed length, width, length/width and 1000-seed weight were 3.51%, 6.13%, 6.11%, and 9.09%, respectively. Seed traits were more stable than cone traits. The seed and cone traits of controlled and open-pollinated families were affected by strong genetic effects and environmental factors.with both rich genetic variation and inherent characteristics, and could be stably inherited There were significant (P < 0.05) or extremely significant positive correlations (P < 0.01) between seed and cone traits and between seed and cone traits and the growth traits of mother trees.

Conclusion The rich genetic variations among the seed and cone traits of P. asperata, as well as the significant or extremely significant correlations between seed and cone traits and between seed and cone traits and the growth traits of mother trees, provide a reference for the precise management and genetic improvement of spruce seed orchards.