Differential Reactivity in Chromosomes as an Indicator of Species in Trillium

Abstract

The pattern of differential chromosome segments produced as a result of cold treatment in a number of collections of T. grandiflorum (Michx. ) Salisb. and T. erectum L. from various parts of the country was detd. in root tips, using the Feulgen technique. All measurements were made upon metaphase chromosomes. The pattern of differential segments is not constant in the 2 spp. Certain regions of differential reactivity appear to be constant as to position within a species, although these segments are not constant as to length. T. grandiflorum (Michx. ) Salisb. and T. erectum L. can possibly be separated from each other on the basis of their pattern of differential segments since 14 segments were found to be constant in position in T. erectum L., whereas 18 such segments appear to be constant in T. grandiflorum (Michx. ) Salisb. Increase or decrease in total length of the diploid chromosome set as a result of cold treatment was found to vary within a species.