Mutation Breeding in Ornamentals

Induced mutation technique is a valuable tool that has been exploited for ornamental breeding for the past 30 years. Mutation breeding has been more successful in ornamental plants because changes in phenotypic characteristics like flower color, shape and size, chlorophyll variegation in leaves, and growth habit can be easily detected. In addition, the heterozygous nature of many ornamental plants offers high mutation frequency. Since mutations are induced in single cells, irradiation of multicellular structures with chemical and physical mutagens will appear as chimeras. However, the use of in vitro culture using adventitious bud techniques has proven to be the most efficient method to avoid chimerism. Mutation by using X-rays and gamma rays has successfully produced a large number of new varieties in different ornamental plants which had been commercialized. Appropriate strategies in mutation induction such as the use of in vitro culture technique in combination with chronic gamma irradiation have proven to be an effective method of mutation induction to produce new promising mutant varieties of ornamentals over a short period of time. During the past two decades, ion beam radiation has emerged as an effective and unique mutagen for improvement in ornamental plants since it produces higher mutation frequencies compared to X-rays and gamma rays. Currently, interest in research has shifted toward the application of molecular breeding and genetic engineering for ornamental improvement, but both have their own advantages and disadvantages. Mutation breeding is still an attractive method for creating genetic variability and has become a routine technique in many vegetatively propagated ornamental plants.