Chromosome Transfer among Meiocytes in Brachiaria nigropedata (Ficalho & Hiern) Stapf (Gramineae)

抄録

Cytological studies of microsporogenesis in tetraploid (2n=4x=36) and apomictic accessions of Brachiaria nigropedata revealed chromosome transfer between microsporocytes in early meiosis. Six, in 20 accessions available at Embrapa Beef Cattle Research Center, presented cytomixis in frequencies ranging from 0.6 to 9.7%. The number of cells involved in the phenomenon varied from 2 to 4, with predominance of the first. Transference of a few chromosomes to the whole genome was found among cells. Prior to cytomixis, chromatin underwent structural alteration similar to what is observed in chromosome stickiness. This is the first report of cytomixis in the genus Brachiaria. Possible origin and implications to pollen fertility are discussed.