Effects of five types of ion beam irradiation on the dry seeds of Gerbera hybrida

Gerbera (Gerbera hybrida) is a commercially important flower in the global floricultural industry that produces various flower colors and shapes.
Although most currently distributed gerbera cultivars are developed through crossbreeding, little is still known about their mutation breeding.
In this study, we irradiated dry seeds of gerbera with five different ion beams to determine the effective elements for mutagenesis and the level of absorbed doses, followed by gene expression analysis of the obtained flower color mutants.
The absorbed doses at which the number of leaves decreased to less than 50% of the unirradiated area (50% decrease leaves number) varied by the element.
The negative growth change rate was higher than that of the positive, regardless of the elemental species.
The highest growth change rate was observed in the irradiation treatments of carbon (C) 100 Gy, neon (Ne) 25 Gy, silicon (Si) 25 Gy, argon (Ar) 50 Gy, and iron (Fe) 10 Gy, which were 7.7-18.2 Gy lower than the dose of 50% decrease leaves number.
Trait/morphological mutants were observed in four plants with double-flower mutation and one plant with flower color mutation, representing 0.16% of the total number of sown seeds.
Additionally, the expression level of an upstream anthocyanin biosynthetic pathway CHS1 gene was drastically reduced in the light purple and white petals compared with the wild-type red petals.
These results indicate that, although the trait/morphological mutation rate was lower than in the case of in vitro seedlings, this study provided good knowledge for the establishment of more efficient mutagenesis techniques for gerbera in the future.

IV Asian Horticultural Congress – AHC2023

T. Hosoguchi, M. Yahata, T. Shimokawa, A. Tominaga

anthocyanin biosynthesis, chimera mutation, growth change, mutation breeding, trait/morphological mutation

https://doi.org/10.17660/ActaHortic.2024.1404.96