ULTRASTRUCTURAL AND HISTOCHEMICAL STUDIES OF TRANSFER CELLS INT HE CALLUS AND APOGAMOUS SPOROPHYTES OF PHYSCOMITRIUM COORGENSE BROTH.

Ultrastructural and histochemical studies reveal that apogamous sporophytes develop spontaneously from gametophytic callus cells of Physcomitrium coorgense which have accumulated starch and developed wall ingrowths. Plasmodesmatal connections are retained between the apogamous outgrowths and the subtending callus. Although apogamous sporophytes lack a recognizable foot, the peripheral cells in the lower part of the seta develop wall ingrowths similar to those in the placental region in sporophytes of sexual origin. [ABSTRACT FROM AUTHOR]