Cytological Chimaeras in Roots of Vicia faba

Abstract

Roots of Vicia faba that had been treated with colchicine (0. 05% aqueous solutions) had meristems containing diploid and polyploid cells. Lateral roots grew from C -tumors and from regenerated primary roots. Secondary laterals grew from the lateral roots on the C-tumors. The composition of the apical meristems of primary, lateral, and secondary lateral roots has been determined. The mean percentage of polyploid cells in lateral roots is greater than in primary roots: the difference between means is 50%. It appears that roots that arise after treatment with colchicine have mixoploid meristems and develop from mixoploid primordia. Mixoploid lateral roots appear to be stable cytological chimaeras in which cells with different degrees of ploidy are distributed throughout the meristem.