Scientists breed fir pollen inside test tube, make they and Douglas fir contain the constituent contact of young embryo next, it is normal to was generated after a week young..

• 科学家们在试管内培育出枞树花粉，然后使它们与道格拉斯枞树含有幼胚的组织接触，一个星期以后就生成了正常的幼...