ABNORMAL MEIOSIS IN THE EARLY GENERATIONS OF THE HYBRID BETWEEN RICE AND SORGHUM

Abnormal phenomena at meiosis are observed in the early generations of the distant hybrid between rice and sorghum.1. F₂ has one more pair of satellite chromosomes than the female parent, F₃ has one to four sat-chromosomes, and almost all chromosomes were attached to the nucleolus.2. The chromosome number varies. The bivalent number are more than 12, and there were chromosome fragments and chromatin grains.3. There were obvious variations in the size of chromosomes.4. Lagging chromosomes in MⅠ and M_Ⅱ, chromosome bridge in AⅠ.5. Secondary association of chromosomes in MⅠ.6. The chromosomes were grouped abnormally in MⅠ and M_Ⅱ.7. The unusual orientation of the spindle and perpendicular double spindles.8. Tripolar division, multipolar division and unequal division.9. Cells with 8-13 nuclei.10. Abnormal phenomena were found at the tetrad stage, such as, unsynchronism, micronuclei, abnormal tetrad arrangement, unequal size of some tetrads. Empty, inviable microspores were formed.The abnormalities at meiosis in the early generations verified that nucleus material of the sorghum was introduced into the genome of the rice by the sexual way.