Effect of nonionizing rays on growth, chemical constituents, and molecular aspects of Catharanthus roseus plant

Background and objective Catharanthus roseus (L.) is a perennial tropical plant and is considered one of the important ornamental and medicinal plants of the family Apocynaceae. It is used as an anticancer and antidiabetic agent. Catharanthus leaves are used for menorrhagia and rheumatism. The laser rays are used as a physical method to improve the germination, the plant growth, and the vigor of the seeds. The study aimed to evaluate vegetative growth, flowering, and marker gene on Catharanthus leaves and to investigate its chemical constituents under the effect of laser rays. Materials and methods The pot experimental study was carried out at greenhouse of National Research Centre, Giza, Egypt, on C. roseus. Two types of laser [helium cadmium (He-Cd) and argon (Ar) laser] were used at different exposure times (0, 4, 8, and 12 min), and various morphological, flowering, chemical constituents were determined. Inter-simple sequence repeat (ISSR) marker was used to illustrate the effect of He-Cd and Ar laser on C. roseus at different exposure time. Results Generally, the highest values of number of leaves, plant height, root length, fresh and dry weight of leaves, and number of days to flower, photosynthetic pigments, proline %, carbohydrate, vinblastine, and vincristine were obtained with 8 and 12 min of He-Cd laser treatments. Conversely, 4-min He-Cd and 8-min Ar laser time exposure recorded decrease in photosynthetic pigments, proline %, and carbohydrate concentration. ISSR showed that mean polymorphic percentage was 25%. ISSR investigation demonstrated that the control, He-Cd laser exposure for 8 min, and Ar laser exposure for 12 min of Catharanthus plant produced unique positive markers, which were found to be mutant specific. Conclusion It was concluded that laser rays with different time exposure had potential effect on growth, flowering, chemical constituents, and the production of Catharanthus plant.