Department of Genetics and Plant Breeding, G.B. Pant University of Agriculture and Technology, Pantnagar-263 145, India
1 Corresponding author, SKUAST-K, Rice Research and Regional Station, Khudwani-192 102, Distt. Anantnag, India.
Various selection indices were constructed for commercial cane sugar (CCS) yield in a population of 22 advanced sugarcane genotypes, tested in 8 environments. Four quality traits, brix, sucrose, CCS or sugar recovery and juice extraction per cent, and cane yield were used to compute genetic gains from selection indices for CCS yield. Selection index (SI) with juice extraction per cent, cane yield and CCS yield itself had maximum genetic gain (14.70%) over straight selection. The next SIs with high genetic gains were cane yield or CCS yield (14.69%), CCS per cent, cane yield and CCS yield or CCS per cent, juice extraction per cent, cane yield and CCS yield (14.47%). and brix. sucrose,CCS and juice extraction per cent, cane yield and CCS yield (13.67%), SIs with any character combination excluding cane yield had low genetic gain (−1.57 to 4.44%) for CCS yield. Exclusion of individual quality traits, brix, sucrose and CCS per cent from SI with any other characters did not result in appreciable decrease in genetic gain. It was therefore, suggestive that after primary selection for sugar content the selection be based on juice extraction per cent, cane yield and CCS yield for maximum improvement in sugar yield.
