Chrysanthemum plants regenerated from ovaries: a study on genetic and phenotypic variation

Abstract

Chrysanthemum (Chrysanthemum × grandiflorum /Ramat./Kitam.) is the second most popular ornamental plant in theglobal flower industry, and there is still a demand for novelty, which forces breeders to search for new sources of variation. The aimof the present study was the evaluation of phenotypic as well as genetic variation of chrysanthemum plants regenerated from ovariesin vitro. In the first vegetative season of plants evaluated in the glasshouse, nine phenotypic variants (16.36%) and 46 (83.6%) true-totype plants were observed. The variation included variegated, marble-like, and lighter-green leaves, and changes in the morphologyof inflorescences and ligulate florets, as well as changes in the shape of corymb. Variants with variegated and marble-like leaves wereunstable. All 55 regenerants had the same ploidy level (2n = 6x) as control plants, estimated by flow cytometry. Genetic analysis basedon RAPD-PCR revealed genetic distances ranging from 0.93% to 7.69% between variants and control plants. It was concluded thatvariable regenerants did not originate from the gynogenic pathway, but they regenerated from somatic tissue and underwent somaclonalvariation.