针叶树育种所面临的一个主要问题是针叶树无论种在那里都需要几年乃至几十年才开始开花结实。此外,一旦开始开花结实,就会产生有一定间隔期或无规则间隔期的球果大小年。这两个因素限制了乡土树种改良方案的效率发挥,然而,通过室内的盆栽育 One of the main problems facing conifer breeding is that it takes years or decades for conifers to begin to bloom and grow. In addition, once the flowering is strong, there will be cone-size years with intervals or irregular intervals. These two factors have limited the efficiency of native species improvement programs, however, through indoor potting