Development of pre-breeding stocks with improved sucrose content over two selection cycles in sugarcane

In a base population comprising twenty three Indian “Co” canes and fourteen commercial hybrids from other countries, improvement in sucrose content was obtained over two cycles of recurrent selection. The parental clones had an average sucrose of 19.40%. Among the crosses involving Indian commercial hybrids, the best was CoC 671 x Co 99002 with a maximum record value of 24.0% brix and contributed more than thirty five per cent selections performing better than the cross average. In the crosses between Indian and Foreign hybrids, two crosses viz., PR 1080 x CoT 8201 and PR 1080 x Co 94008 were the best with 23.4% brix which gave more than 23 per cent selections with high juice brix. The cycle I hybrid progenies had juice sucrose values ranging from 17.0% to 23.0% with a mean of 21.6%. The cycle II progenies recorded average juice sucrose of 22.0% with 13.40% improvement over base population. After two cycles of selection, the progress made for sucrose content in comparison with the base population is substantial. Combined evaluation of 472 high sugared clones identified from cycles I and II indicated potential pre-breeding stocks with early high sugar content which could be exploited in future. The clones 00-0402, 00-1805, 01-0031, 01-0047, 02-0288 recorded more than eight per cent improvement in sucrose content over the zonal check variety CoC 671 under early maturity group.