Modified Ovule Clearing Technique to Examine Monosporic Apinagia-type Embryo sac Development in Indotristicha ramosissima (Podostemaceae- Tristichoideae)

Abstract

In this current study, a re-examination of various stages of monosporic embryo sac development in Indotristicha ramosissima (Podostemaceae-Tristichoideae) has been attempted utilizing a modified ovule-clearing technique specifically tailored for this unique angiosperm family. It is worth noting that ovules within the family Podostemaceae typically contain silica, which poses challenges for tissue clearing. Consequently, there has been limited success in ovule clearing within this family. My investigation confirmed the presence of a 4-nucleate and monosporic Apinagia type of embryo sac in this species, in contrast to prior beliefs of embryo sac following a bisporic Allium type pattern. Additionally, my findings revealed that the embryo sac develops only after the degeneration of one of the dyads during megasporogenesis.