Structural Modifications of the Female Gametophyte Induced by Temperature in Nicotiana tabacum

Effect of environmental conditions on formation of Nicotiana tabacum L. megagametophyte was studied. It was established, that unfavorable temperatures can specifically modify the structure of embryo sacs (ES). At low temperature (9/5 °C), ES with a reduced number of cells or with egg-like synergide(s) can be formed; at high variable (40/25 °C) or constant (37 °C) temperatures, ES with excessive numbers of cells or with synergide-like egg cells arise. Total frequencies of the changed ES patterns varied from 8 up to 35 % per plant and depended on the plant genotype and conditions of exposure. This revised version was published online in July 2006 with corrections to the Cover Date.