Catharanthus roseus L. (G) Don, commonly known as Madagascar periwinkle, is
an important medicinal plant receiving much attention from researchers. This
plant is a rich source of terpenoid indole alkaloids (TIAs). The gamma
radiation and somaclonal variation may provide suitable methods for genetic
changes to increase medicinal components of C. roseus. In the present study,
30 and 60 (Gy) gamma rays were irradiated on seeds. C. roseus seeds were
cultured in Murashige and Skoog (MS) medium in three different groups, 0 Gy
(control) 30, and 60 Gy gamma irradiations. Morphological characteristics of
regenerated plantlets were measured for surface area of leaves, stem length,
root length, and fresh weight. The genetic variations were evaluated using
nine inter-simple sequence repeats and 25 sequences related amplified
polymorphism markers. Morphological results showed a significant difference
between studied groups in leaf surface and twisted leaf in 60 Gy irradiated
plantlets. The analysis of molecular variance revealed the significant
genetic difference among groups. STRUCTURE analysis showed genetic
variability both within and among groups. Using the NJ tree analysis, the
plants studied were categorized into three distinct groups, which were
supported by principal coordinate analysis (PCoA). In conclusion, gamma
irradiation produced morphological and genetic changes in C. roseus
regenerated in vitro plantlets providing to be a suitable method for further
mutation breeding in periwinkle.