Constructing and comparing selection indices for early growth traits in Saccharum spontaneum

Saccharum spontaneum is the major donor of important traits like vigour, hardiness and ratooning potential to modern sugarcane cultivars. Identifying S. spontaneum clones with high early vigour and tillering ability is essential to include them in hybridization program. Forty three Saccharum spontaneum accessions were evaluated for number of tillers per clump, stalk length, stalk diameter, number of leaves on the main stem, leaf length and leaf lamina width at 90 days after planting. Variance components for these traits indicated high heritability coupled with genetic advance for leaf width and stalk length indicating the preponderance of additive gene action for these traits. The comprehensive index C_jvalue, Smith-Hazel's selection index (SHI) and rank sums of all the traits indicated six clones viz, IND 99–848, IND 99–881, IND 99–849, IND 99–850, IND 99–984 and IND 99–847 were superior clones and can be utilised in pre breeding programmes as potential donors in identification of bioenergy canes. Among the methods studied, DTOPSIS was comparatively effective in selecting the genotypes.