1998 Volume 63 Issue 3 Pages 305-309
Cytogenetic analysis on two lots of maize genotypes consisting of inbred lines, singlecross hybrids and double-cross hybrids grown in the South and Center West Regions of Brazil revealed the occurrence of spontaneous mixoploidy in the anthers of some plants. In the South Region the anthers showed only diploid and tetraploid cells, with the tetraploid ones presenting nuclear fusion. In the genotypes grown in the Center West Region the anthers showed a mixture of diploid, tetraploid, hexaploid and octaploid cells. In addition to nuclear fusion, some cells of these genotypes presented just cytoplasm fusion, with the nuclei remaining individualized. The percentage of poly ploid cells ranged from 1.0 to 47.6. The probable origin of the phenomenon and its implications in maize breeding are discussed.