Abstract:

Cytochimeras are important materials used to study the behaviors of the cells with different ploidies in a tissue. The epidermal cell size and pollen size are commonly used to indirect detective the cell ploidy levels in L1 and L2 layers, because ploidy is one of the parameters that influence cell size; higher ploidy levels usually result in proportionally larger cells. To my knowledge, there is not any published report for direct determining ploidy of the somatic cells in different layers of a cytochimera. During a histological investigation of Pelargonium zonale ‘little lady’, a method was developed, which was able to directly determine ploidy by counting chromosome number of the somatic cells in different layers of cytochimeral tissue in embedding slices stained with Toluidin blue. In the mean time, the processes of nuclear division in cytochimeral tissue were observed with this method. Therefore, it can not only be used to directly determine the ploidy of the somatic cells in different layers in cytochimera, but also be used for study of cell division procedures of mutated cells in cytochimeras.

Key words: Pelargonium zonale, cytochimera, tissue section, ploidy level, cell division