Preliminary results on studies of in vivo and in vitro sexual reproduction of Salix viminalis L.

摘要

In vivo and in vitro self-pollination of whole pistils of some clones of Salix viminalis enabled to obtain mature seeds containing cotyledonary embryos which after the transfer to MS medium developed into wholly formed seedlings. Pollination in vitro of placentae led to abundant pollen germination and formation of tubes which occasionally they were entering the ovules through micropyle. Fertilized ovules normally developed into germinable seeds. Distant pollination of stigmas in vivo and in vitro with pollen grains of Populus tremula, P.tomentosa, P. lasiocarpa?showed the ability of pollen to germinate and to form tubes several hours after pollination. Some tubes penetrated the styles but did not enter into the placenta. When placentae were directly pollinated than pollen germinated abundantly and occasionally pollen tubes were found entering the micropyle. Embryological analysis of those ovules performed 3-5 days after pollination demonstrated the presence of globular embryos with several endosperm nuclei. The technique of in vitro placental pollination works well for Salix viminalis and it could probably be applied to other Salix species.Additional key words: willow, poplar, in vivo, in vitro stigma and placental pollination, embryo development