The caryologic technics aim to determine the level of polyploidy of a population or a species. The information brought for the knowledge of the chromosomal number of a species, is of various nature. Thus for several years the caryology has made it possible to better understand the taxonomy of a species, its tendencies evolutionary, its geographical distribution and the phenomena of its speciation [16]. Any time the chromosomal number, although being able to
characterize a plant or a group of plants is not a character constant.It can vary inside a group, tribe, family or kind, and within same species[12,15,16]. The technics of identification of the most known chromosomes are: traditional technics based on the histological cut, the Technics of Feulgen which has like action to colour in purple red the DNA chromosomal [6,7,8] and technics of bands or mechanisms that it brings into play are related to the physicochemical properties of the chromatin and the condensed form of the chromosomes. To highlight the chromosomes of a species
we observed somatic mitosis carried out bolsters of young roots. The principal stages of the technics has to follow are: the pretreatment, fixing, storage, the hydrolysis, colouring, the assembly and observation. All this work was completed on young roots of Solanum sodomeum L. or the number of the chromosome is still questioned.
