The Nuclear DNA Content of the Egg, the Zygote and Young Proembryo Cells inHordeum

SUMMARYThe nuclear DNA content of Feulgen stained zygotes and young proembryo cells was investigated by microdensitometry in three barley genotypes. Apart from a few abnormally low estimates for nuclei in newly fertilized egg cells (caused by failure of the staining reaction), the estimated DNA contents of nuclei in the zygotes and 2-celled proembryos were within, or close to, the expected 2C-4C range. The present result differ from those for ‘Hannchen’ barley in which it was claimed (MERICLE and MERICLE 1970) that the nuclear DNA content of zygotes was as high as 16C and minimally 8C, but agree with WOODWARD'S (1956) results for Tradescantia.