Mapping of C-banded Crepis chromosomes by imaging methods.

Crepis capillaris is a highly suitable model plant for a computer-aided analysis of chromosomes because of its small number of chromosomes and well-defined bands. The identification of both large and small bands by means of profiles [grey value-function (position)] is frequently not possible with simple discrimination. In this case, dynamic curve fitting gives exact results by sliding discrimination. The application of low-pass filters, with a filter matrix size of 75 x 75 pixels, to the original image generates a reference image that can be used for sliding discrimination. The relevant bands are visible by the subtraction of the filtered image from the original image. The computerized bands correspond exactly to band regions recognized visually. Human vision is another approach to improve the quantification in cytogenetic results. The connection between the visual inspection and the imaging methods will reduce the subjective interpretation of individual researchers. The knowledge-based analysis may be a significant factor in the near future to answer unsolved questions.