Female gametophyte in two Kenyan species of Inversodicraea (Podostemaceae).

Abstract

The ontogeny and organization of the female gametophyte in I. bifurcata and Inversodicraea keniensis sp. nov. in Kenya were studied. The ontogeny of the female gametophyte was classified under the Apinagia type. The primary chalazal nucleus degenerated at the two-nucleate stage. The female gametophyte was four-nucleate and four-celled, and consisted of two pear-shaped synergids, a large central egg cell, and a polar cell. A filiform apparatus was present in the synergids. In the female gametophyte, antipodal cells were not observed. Only a single fertilization occurred in the family. The nucellar plasmodium was formed before fertilization in Inversodicraea. The effects of tension force and lytic enzymes during nucellar plasmodium organization and its significance are discussed.