Standardization of sterilization protocol for in vitro propagation of chrysanthemum cvs. “Candor and Local Yellow”

The study aimed at standardization of a sterilization protocol for two most practically functional explants viz. nodal segments and ray florets of Dendranthema grandiflorum Kitam cvs. “Candor and Local Yellow”. Different sterilant concentrations and combinations were tried for both the explants which differed significantly with each other and showed significant effect on culture asepsis and explant survival in both the cultivars. For nodal explants, sterilization regime consisting of Carbendazim 200 ppm for 30 minutes followed by 0.1% mercuric chloride treatment for 8 minutes followed by a final dip in 70% ethyl alcohol for 10 seconds was concluded to be the standard for both the cultivars for further studies. Moreover, a reduction in Carbendazim concentration to 100 ppm and mercuric chloride concentration to 0.05% also proved to be optimally effective. In contrast, the sterilization treatments consisting of mercuric chloride at 0.05% for 4 minutes and 0.1% for 2 minutes followed by a final rinse with 70% ethyl alcohol for 10 seconds proved to be statistically equally effective for ray florets and were concluded the best with respect both to culture asepsis and explant survival.