Combining ability and heterosis for disease index of red rot in sugarcane (Saccharum officinarum L.)

Abstract

Combining ability and heterosis for disease index of red rot were studied in the progenies of nine sugarcane (Saccharum officinarum L.) clones to identify suitable parents and crosses for further exploitation in breeding programmes. Based on the combining ability results, Co 8347, ISH-021 and Co 86011 were identified as good general combiners for imparting red rot resistance. Use of these clones, with high (negative) gca effects, would be advantageous in poly cross method of breeding. The association between sca effects and heterosis over mid-parent indicated that the sea effects were not so prominent to cause unidirectional heterosis. Hence, per se performance, sea effects and heterosis were considered to identify Co 7201 x Co 86011, Co 8347 x Co 1148, Co 89009 x Co 86011 and ISH-021 x Co 1148 as the best specific combinations for red rot disease index. Both additive and dominance variances were equally important and heritability (in narrow sense) was 0.51 for red rot resistance in sugarcane. High value (0.97) of heritability (in broad sense) indicated the negligible influence of environment on red rot disease development in sugarcane.