选择育种是遗传改良的主要手段,它贯穿于育种过程的每一个环节。对于经济林树种,尤其是以种实生产为目的经济林树种,选择的根据不仅取决于种实产量,还应考虑与产量有密切关系而遗传力又较高的性状的选择。如花期受气象因子影响大的地区,要考虑花期物候的选择;生物量分配上有利于生殖生长的性状,如分枝习性、侧枝长短、花果序及果皮厚薄等也 Breeding selection is the primary means of genetic improvement, which runs through every aspect of the breeding process. For economic forest tree species, especially for the purpose of seed production of economic forest tree species, the choice of not only depends on the actual production, but also with close and yield and genetic selection of higher traits. If the florescence is affected by meteorological factors in large areas, we must consider the choice of flowering phenology; biomass distribution is conducive to reproductive growth traits, such as the branch habits, the length of the branches, flower order and pericarp thickness