ORGANELLE DISTRIBUTION AND APPORTIONMENT DURING MEIOSIS IN THE MICROSPOROCYTE OF GINKGO BILOBA L.

Abstract

Microsporocytes of Ginkgo biloba were observed in stages of meiosis with both the light and electron microscopes. After telophase I, all of the plastids and mitochondria were located in the equatorial region of the cell and this non‐random pattern of distribution was maintained until nuclear division had ceased. The ensuing apportionment of organelles among tetrad members was approximately equal, and was coincident with centripetal formation of the partitioning walls. Although no mechanisms for the initial equatorial positioning or later dispersal of the organelles could be ascertained, membrane proliferations were prevalent and may have played a role in maintaining the pattern of organelle distribution through the duration of the second division. Microtubules, which permeate the central region of the cell may have also functioned to maintain the non‐random pattern of organelle distribution.