Characteristics of Tetraploid and Ploidy Chimera Induced by Colchicine Treatment in Citrus

Abstract

We investigated leaf and flower bud characteristics in tetraploid plants and 2x-4x-4x ploidy chimeras from 20 citrus cultivars and strains induced by colchicine treatment. With regard to tetraploid plants, the leaf thickness was larger and stomatal density was smaller than the corresponding characteristics of diploid plants in all cultivars and strains. On the other hand, there were no characteristics considered to show a significant difference between tetraploid and diploid plants in all cultivars and strains regarding the flower bud. With regard to 2x-4x-4x ploidy chimeras, the leaf thickness was larger than that of diploid plants in all cultivars and strains, but the stomatal density did not exhibit a definite tendency. Furthermore, there were no characteristics considered to show a significant difference between 2x-4x-4x ploidy chimeras and diploid plants in all cultivars and strains for the flower bud. These characteristics were available for roughly selecting tetraploid plants and 2x-4x-4x ploidy chimeras from a colchicine treated population, leading to efficient ploidy analysis by flow cytometry.