Callogenesis is one of the tools in sugarcane tissue culture for generating agronomically significant variation. Tissue culture derived variations are known as somaclonal variation. The study was carried out to investigate the effect of MS media supplemented with 1.0 mgL-1 of NAA (naphthalene acetic acid) and 2.0, 2.5, 3.0, 3.5 and 4.0 mgL-1 of 2,4-D (2,4-dichlorophenoxy acetic acid) on somaclonal variation in in vitro regenerated sugarcane genotype CO421, CO945 and N14. Screening of somaclonal variants was done on four months old field grown sugarcane plants that had originally been generated through in vitro culture. The morphological characters studied included; tillering capacity, diameter of the cane, internode length, leaf length and width. Multivariate analysis of variance (MANOVA) revealed patterns of phenotypic diversity of quantitative traits studied. Means of each quantitative character were standardized before subjecting to the principal component analysis (PCA). The standardized data of the five (5) quantitative traits were then used as an input for the PCA biplot loading and cluster analysis. Application of 2,4-D to callus formation media (CFM) led to somaclonal variation irrespective of the sugarcane genotype used. The observed variation however had no correlation to the hormonal concentration supplemented in the CFM. The dendrogram demonstrated variation among the somaclones based on morphological traits could be a valuable source for sugarcane improvement program.

Keywords: Callus culture, callogenesis, genotype, morphological traits, sugarcane, somaclonal variation