Meiotic Chromosome Dynamics in Some Populations of Panicum Maximum Jacq. in Southwestern Nigeria
Thirty-five accessions of Panicum maximum Jacq. were collected from parts of the states of southwestern Nigeria to study the meiotic dynamics of the populations. The accessions group into two field forms: the heavy tillering, robust, tall, long and broad-leafed with relatively fat culm and the low-tillering, not so robust, moderately tall, not so long .and narrow-leafed with thin culms. All accessions studied have chromosome number 2n = 32, including the accessions from the Oil Palm Plantation at Apoje, Ijebu-Igbo in Ogun State, for which a chromosome number of 2n = 28 had previously been reported. How this chromosome number could have been arrived at is discussed. Meiotic irregularities of quadrivalents and univalents occurred with high frequency. A mean of about 13 bivalents per cell with regular occurrence of 1 5 quadrivalents per cell suggest that P. maximum is a segmental allopolyploid.