Comparison of family selection methodologies used in the initial phase of sugarcane breeding

The simplified system (SS) is a new method of selecting families in the first experimentation phase used in some sugarcane (Saccharum officinarum L.) breeding programs in Brazil. In the SS, clones are obtained from families whose genotypes are not individualized in the field. Such selected clones are used to compose the cloned family trial. In the conventional method (CM) of breeding, each genotype is individualized to form part of the family evaluation experiment. This work aimed to compare and verify if the SS provides genetic information at least similar to the CM. Two experiments were conducted, one for the CM and the other for the SS. Sixty full-sib families were evaluated in each experiment. The characteristics evaluated were average stalk height, average stalk diameter, the content of total soluble solids (BRIX), the number of stalks per meter, average stalk mass, tonnes of stalks per hectare, and tonnes of BRIX per hectare. The mixed model methodology was used to estimate the genetic parameters and predict the families' genotypic values. Both methods enabled high precision in the evaluation of families and similar average genetic gains (10.1% for CM and 9.6% for SS). The SS makes it possible to select families with high genotypic value, high accuracy, and genetic gains comparable to the CM. Therefore, although the SS presents similar results as the CM, its simplicity and ease of being installed in the field in a smaller experimental area make it a promising methodology for selecting cloned families in a sugarcane breeding program.