Somatic chromosome map of rice by imaging methods.

Rice somatic chromosomes were completely identified and quantitatively mapped based on an image parameter, condensation pattern (CP), or a chromosomal density profile determined by imaging methods. The CP corresponds to the compactness of the chromatin fibers along the chromatid, which is characteristic in small plant chromosomes such as rice chromosomes at the mitotic pro-metaphase stage. The standard CP for every chromosome was obtained by averaging 60 CPs from 30 chromosome spreads. Each standard CP exhibited a characteristic pattern of the chromosome, which enabled it to be distinguished from the other chromosomes. An ideogram based on the numerical data and the standard CP was established. The chromosomal address was also determined based on the degree of condensation, and the fractional length of each chromosomal address was quantitatively presented.