QUINACRINE FLUORESCENCE STUDIES IN PARIS POLYPHYLLA

Abstract

The chromosomes of Paris polyphylla Smith (2n = 10, 20) are the largest in the plant kingdom. They possess large regions of reduced fluorescence in addition to discrete fine banding. Excluding the 'bubbling', an effect of fixation, the discrete finer banding pattern is very constant and specific for each chromosome type. These finer bands, which may show either reduced or enhanced fluorescence, often do not traverse the chromosome; this could be attributed to the length of the banded segments involved (usually very short) and the degree of spiralization at mitotic metaphase which may not fill a complete gyre in the chromosome spiral. Cold-sensitive H-segments, which are located distally and show reduced fluorescence, are present only in the diploid plants. The interphase nuclei have a unique structure and appear composed of well defined minute granules which exhibit well differentiated regions of reduced and enhanced fluorescence when stained with Quinacrine.