The development of embryo sacs in in vitro ovaries of Nicotiana tabacum L

Abstract

The development of female generative structures in ovaries in vitro of Nicotiana tabacum L. depending on excision stages, nutrient media and genotypes has been investigated. It was found that in ovaries excised at the stage of megaspore mother cell, both megasporogenesis and formation of embryo sac mother cell occurred normally. After 7 days cultivation, mature embryo sacs (ESs) were recorded in 30.2% of ovules, 78% of ESs were of normal structure. In ovaries excised at the stage of sporogenesis or one-nucleate ES, mature ESs were found after 4 and 3 days in 79.8 and 95.0% of ovules, respectively, a significant part of ESs (90.0 and 97.0%) being of normal structure. Similar results were obtained for four other tobacco genotypes. The use of different nutrient media demonstrated that increasing concentrations of growth substances in the medium can modify ES developmental patterns. It was concluded that tobacco ovaries in vitro are a promising tool for experimental study of ES development.