Abstract
Okazaki et al. (2005) reported induction of 2n pollen by arresting the meiotic process with nitrous oxide gas. However it has not been known mechanism by which 2n pollen was induced with nitrous oxide gas. In this study, we observed microsporegenesis in non-treated and N2O-treated pollen mother cells (PMC) in lily, using fluorescence-labeled tubulin-specific-antibody and aceto-orcein stain.
In the prophase of non-treated PMC, most of the microtubules surrounded chromosomes instead of preprophase band formation. In the metaphase, normal meiotic spindle was formed, followed by formation of cell plates and the resulting tetrad. On the other hand, in the N2O-treated PMC, depolymerization of microtubules was observed and resulted in arresting the meiosis, whereas cell plate was formed normally. Consequently, two copies of the genome were situated in one daughter cell of PMC and no genome in the other daughter cell, indicating formation of diploid pollen.
