Inheritance for fibre in sugar cane (Saccharum spp. hybrids)

The inheritance of fibre in sugar cane (Saccharum spp. hybrids) was investigated in 39 biparental crosses involving 22 parental genotypes. Genetic analysis was based on North Carolina mating design II analysis, combining ability analysis and parent-offspring regression. The results showed a role for both additive and non-additive effects in the inheritance of fibre, although the former was predominant. General combining ability (GCA) of the parents was able to accurately predict the performance of progeny in all 8 M x N ('M' male cultivars crossed with 'N' female cultivars) mating designs. The high fibre genotypes were the best general combiners, while the low fibre ones generally produced negative GCA values. Narrow sense heritability (h(2)) based on North Carolina mating design ll analysis, was 61.2%, with broad sense heritability (H(2)) of 95%. The estimate of h(2) based on mid-parent-offspring regression analysis was slightly higher (68%). There was a greater effect of the female parent compared to the male parent in the inheritance of fibre. Clonal breeding for fibre combined with other important economic characteristics using a family selection approach is suggested.