Résumé
The segregation of 12 heterozygous isozyme markers was analyzed among F2 plants and 51 anther culture (AC)-derived lines obtained from the japonica .times. indica cross of rice IRAT 177 .times. Apura. All the lines except two were homozygous products of recombination of the two parental phenotypes. Doubled haploid (DH) lines derived from plants regenerated from the same callus were identical, confirming previously obtained results in rice. Surprisingly, some lines derived from different calli wre also identical, suggesting a phenomenon of early callus fragmentation. All these observations at the isozyme level were confirmed by field evaluatio. Deviations of segregations from the expected 1:1 ratio were observed at 4 loci among the DH lines. Among these, two were also noted among the F2 plants. The two other distortions, both in favor of the japonica allele, were observed specifically in the AC-derived materials. Although this concerns a small proportion of the genes under study, it suggests that the embryogenic microsporal population does not represent a random gametic array. On the other hand, evaluation of recombination between isozyme genes located on chromosome 6 appears consistent with F2 data and data previously recorded on the other japonica .times. indica crosses. The potential use of isozymes in breeding doubled haploids derived from remote crosses in rice is discussed.