Induction of mutant cultivars in H. aromatica (Spreng.) Schott via gamma irradiation

This research focused on generating novel traits in H. aromatica (Spreng.) Schott through mutation breeding using gamma irradiation.
In 2022, tissue-cultured plantlets were subjected to chronic gamma irradiation at doses ranging from 0 to 100 Gy, using a Cobalt-60 source in a Gamma Chamber GC-5000 at the Thailand Institute of Nuclear Technology (TINT). The lethal dose 50 (LD₅₀), observed 40 days post-irradiation, was calculated at 56.33 Gy.
Among the treatments, plantlets exposed to 20 Gy and subcultured over five vegetative generations (M₁V₅) exhibited variations in leaf coloration.
These plants were subsequently rooted and acclimatized in pots filled with the growing medium under greenhouse conditions at TINT. The mutated lines have since been stably propagated for more than five generations.
Three unique mutants from the 20 Gy treatment displayed distinct leaf color changes.
The first developed mint-green leaves with remnants of the original pattern.
The second showed light green foliage.
The third produced leaves so pale to nearly white.
These results highlight the effectiveness of gamma irradiation as a tool for accelerating genetic diversification of H. aromatica (Spreng.) Schott.

II International Symposium on Botanical Gardens and Landscapes

L. Maikaeo, V. Puripunyavanich, P. Orpong, V. Khamvarn, C. Kongpeng, R. Khamsawat, J. Klunmak

gamma ray, breeding, Homalomena, variegation, mutation

https://doi.org/10.17660/ActaHortic.2026.1455.28