Family evaluation for quality traits in South African sugarcane breeding programmes
International Sugar Journal
South African Sugarcane Research Institute, P/Bag X02, Mount Edgecombe, South Africa
Family evaluation involves the selection or rejection of entire families of seedlings based on information derived from replicated family plots, and is widely practised in sugarcane breeding programmes. After family evaluation, individual seedling selection is restricted to the selected elite families. Family evaluation data is also used to determine breeding values of parent populations. The objectives of this study were to determine the effectiveness of family evaluation and determine potential selection gains over time for quality traits across South African Sugarcane Research Institute regional breeding and selection programmes. Data for various quality traits were collected from Stage I (Single Stools) of all the regional breeding programmes and analysed using the Mixed Procedure of the Statistical Analysis System. There were highly significant (P<0.001) differences between families for the effectiveness of family selection. There were increasing family effects differences with advancing series, indicating the cumulative benefits of family selection. Estimated recoverable crystal (ERC) % cane, Pol % cane and Brix % cane produced the largest gains from family selection, indicating that the current approach is effective. Brix % cane, a trait that can be easily measured with a hand held refractometer, could be used to evaluate within-family variability, an important parameter for family evaluation. The 12-month programmes produced larger gains from family selection than the longer cycle programmes. Future studies should determine the breeding values of parent populations.
Population statistics; Sugar cane; Breeding programmes; Broad-sense heritability; Covariance parameters; Cumulative benefits; Plant breeding; Research institutes; Selection gains; Statistical analysis systems; Quality control