Isolation of Individual Egg Cells and Zygotes in Alstroemeria Followed by Manual Selection with a Microcapillary-connected Micropump

Aims To develop a procedure for isolating living egg cells and zygotes from Alstroemeria ovules. Scope An attempt was made to isolate egg cells and zygotes from the ovules of Alstroemeria aurea. The ovules were histologically observed using a clearing procedure which revealed the localization and sizes of the embryo sacs and egg apparatus within the ovules. For the isolation of egg cells, ovules were cut into sections with a surgical blade and treated with an enzyme solution. Subsequently, these ovule sections were dissected using a glass needle under an inverted microscope. Egg cells successfully isolated by this procedure were collected using microcapillaries connected to a micropump. For zygote isolation, ovules were excised from ovaries 24 h after self-pollination. By treating excised ovules with an enzyme solution and subsequently dissecting them using a glass needle, zygotes were successfully isolated from the ovules and collected with a microcapillary. The isolated zygotes were associated with pollen tubes and one of the synergids. Egg cells and zygotes were viable for up to 2 h following isolation, as determined by fluorescein diacetate staining. Conclusions The procedures for isolating egg cells and zygotes in Alstroemeria were established, and each egg cell and zygote was captured with a microcapillary.