HETEROSIS AND COMBINING ABILITY IN UPLAND COTTON (G. HIRSUTUM LINN.)

Abstract

Heterosis and combining ability were studied in the generation in a ten parent dialJel cross for number of sympodia per plant, number of bolls per plant, plant height, ginning percentage and seed cotton yield per plant The variance due to GCA and SCA were highly significant for all the characters studied. The magnitude of GCA and SCA ratio revealed that the genetic system controlling the characters viz. number of sympodia per plant, number of bolls per plant, plant height and seed cotton yield per plant was largely due to additive gene effect The nonadditivc gene action was important for ginning percentage. The parents, Tx-macaos and Super-okra were the top general combiners followed by Nectariless. Tx-macaos and Super okra produced appreciable heterosis and SCA effects in most of the cross combinations, Superokra x Fregobract, Tx-macaos x Reba B50, Tx-macaos x Rupali and Superokra x Yugoslav early were found as better crosses as they manifested higher heterosis and higher SCA effects for seed cotton yield and Its components.