M. SHANTHI PRIYA*, K.H.P. REDDY, M. HEMANTH KUMAR, V. RAJARAJESWARI, G. MOHAN NAIDU AND B. RUPESH KUMAR REDDY

Department of Genetics and Plant Breeding, S.V. Agricultural College, Tirupati-517 502.

ABSTRACT

Seventy-seven genotypes of sugarcane selected from the first clonal stage were evaluated at Agricultural Research Station, Perumallapalle, Andhra Pradesh, from 2011 to 2012 for diversified uses viz., biomass per cane, fibre yield, theoretical yield of alcohol, commercial cane sugar (CCS) yield and cane yield in second clonal stage. The main objective of a selection programme is to shift the mean to a new peak by directional selection. The plant breeder will have to base his selection on a combination of a few important characters related to the main character under consideration in the form of a selection index by appropriate weightages assigned to the phenotypic values of each character so that the genetic gain in the character under consideration will be maximum without any loss in other important characters. Selection indices provide the means for making use of correlated characters for higher efficiency in selection for characters of low heritability. Selection index is a tool, which breeder can use successfully for selection on several characters simultaneously by discriminating the desirable ones on the basis of phenotypic performance. Among one hundred and twenty seven different selection indices formulated for fibre yield, higher relative efficiency of 1328.62 coupled with high genetic advance (57.13) was exhibited by the combination involving six traits viz., fibre yield (X1), shoot population at 240 DAP (X2), number of millable canes (X3), single cane weight (X4), CCS yield (X6) and cane yield (X7)

KEYWORDS:

Selection indices, sugarcane, fibre yield.