[Reproductive development of initial sporophytes in Pinus sylvestris L]

The reproductive development of Pinus sylvestris from generative primordia to sporophyte initial (embryo tier of 16-celled proembryo) was studied. In the reproductive cycle, three types of stages are distinguished and described in association with: 1) hereditary program formation; 2) a new reproductive initial origin, and 3) increase in propogative energy. The layout of disposition of these stages in the reproductive cycle is given.