Etude Ultrastructurale des Coiffes des Pivots de Cacaoyer (Theobroma cacao L.)

In Theobroma cacao, taproots caps are characterized by a strongly polarized organization with sedimented amyloplasts in the lower part of the cell and nucleus in the upper part. Between the amyloplasts and the nucleus a well developed vacuolar system is found, which seems to be a common feature of statocytes in woody plants. Along longitudinal and transversal walls the endoplasmic reticulum forms elongated cisternae and coiled netlike elements between the amyloplasts and the lower wall. After rotations of 90° or 135° of the root system, the migration of amyloplats is synchronous neither in a same cell nor through the statocytes of a same cap. Migration speeds are similar to those registered in other woody species.