CYTOGENETICAL STUDIES OF MACROMUTANTS INDUCED BY NANOPARTICLES (Cu, CdS, CuO and ZnO-NPs) IN SESAMUM INDICUM L

A total of 23 phenotypic mutants were screened in M2 plant population (7112) of Sesamum indicum L. (Family: Pedaliaceae) affecting seedling colour, leaf traits, stem characteristics, branching nature, floral colour, fruit characteristics and maturity following dry seed (moisture content – 7.40%) treatments with nanoparticles (copper, cadmium sulphide, copper oxide and zinc oxide – 1.00, 2.00 and 4.00 µg/ml, 3 and 6h durations), ethyl methanesulphonate (EMS – 0.25, 0.50 and 1.00%, 3 and 6h) and gamma irradiations (50, 100, 200, 400 and 600 Gy). Viable mutation frequency is found higher in gamma irradiation followed by ZnO-NPs, CuO-NPs, CuNPs, CdS-NPs and EMS. A total of 9 different macromutants types are found in Cu-, CuO- and ZnO-NPs, 11 in EMS and 13 in CdS-NPs and gamma irradiations. Excepting viridis (non-viable), all macromutants bred true at M3. Reciprocal crossings performed between mutant and normal plant types suggest that the mutant traits are controlled by nuclear genes (monogenic recessive and digenic) and they segregated in accordance to Mendelian pattern of segregations. Meiotic analyses reveal that normal and mutant plants were cytologically alike (2n=26) suggesting that mutation is not the consequence of chromosomal disturbances. Results highlight mutagenic potentiality of NPs alike to that of the conventional mutagens used as positive controls. Key words: Sesamum indicum, macromutation, nanoparticles, EMS, gamma irradiations, cytogenetical studies