Cytomixis in Pollen Mother Cells of Urochloa panicoides P. Beauv. (Poaceae)

Abstract

Cytomixis generally refers to the migration of chromatin from one cell to the other through cytoplasmic connections. The phenomenon was first described by Kornicke (1901) in pollen mother cells (PMCs) of Crocus sativus and the term was coined and defined by Gates (1911). It has been reported more commonly during microsporogenesis in a wide range of angiosperms which include genetically unbalanced types such as hybrids (Nettancourt and Grant 1964, Salesses 1970), mutants (Gottschalk 1970, Datta and Biswas 1984), triploids (Salesses 1970, Semyarkhina and Kuptsou 1974), apomicts (Mantu and Sharma 1983) and also in normal diploids (Omara 1976, Morisset 1978). In addition, such migration of chromatin has been reported to occur in mitotic cells (Sarvella 1958, Bowes 1973) and between tapetal cells and PMCs (Cooper 1952). Cytomixis has been induced in the root tip cells of Vicia faba (Bobak and Herich 1978). Although these studies established the phenomenon as a cytological fact, the views regarding its occurrence, cause and significance have been varied and speculative. The phenomenon of cytomixis has been recorded by Church (1929) in certain members of Poaceae who pointed out that the occurrence of cytomixis in hybrids is very striking. It has been reported in many cereals and their hybrids (vide Kamra 1960). The present investigation records cytomixis for the first time in the genus Urochloa, in U. panicoides P. Beauv. The cytological consequences of cytomixis and its significance are also discussed. © 1987, Japan Mendel Society, International Society of Cytology. All rights reserved.