Abstract: Four lines of common wheat, Chinese Spring, with different alien cytoplasms, G, S^v, D² of M^u, were crossed with 11 lines of common weat with different genotypes as parent, in order to explore the relationship between cytoplasmic male sterility and genome by means of observing and analyzing seed-set rate of the crossing generation variation of fertility and Phenotype, and chromosome behaviour at meiosis. The result showed that the seed-set rate of the crossing generation depends on he parent genotype. The fertility in F₁ hybrids is very complicated, that is, there are either some fertile hybrids but some sterile hybrids in combinations of crossing diffrent alloplasmic "Chinese Spring" with the same prent, indicating that the fertility is affected by the cytoplasm. Cytoplasmic effect appears on some characters, for in stance, mature period, staminal form, growth power and resistance to diseases, ets. Some nucleus-cytoplasm combinations with significant heterosis could be selected in the offsprings. Some alien cytoplasms affect chromosomal behaviour at meiosis so that bivalent can be increased or decreased in number in pollen mother cells, and some micronuclei formed in tetrads and abnormal tetrads produced.

Key words: Alien cytoplasm, Fertility, Nucleo-plasmic hybrid