Location of Centromere and Interchange Breakpoints in the Pachytene Chromosome of Rice. : Genetical studies on rice plant, LXXI.

For the purpose of establishing the chromosome map in rice plant, the locations of interchange break points and centromeres were determined by the pachytene analyses in reciprocal translocation heterozygotes and the F1 hybrids produced by the crossings between two kinds of reciprocal translocation homozygotes in which one chromosome was involved in the two interchanges in common. The position of the centromere and the loci of ten marker genes and twenty-three break points were cytologically allocated in six kinds of chromosomes, i.e., the first, second, third, ninth, tenth and eleventh. The karyotype was estimated by measuring arm ratio and relative length in pachytene chromosomes. The authors propose to revise the correspondence of the number between the chromosome types and linkage groups.