Uso do coeficiente de repetibilidade na otimização da seleção de genótipos de cana-de-açúcar

Abstract

The present study aimed to estimate the repeatability and determination coefficients for the traits tons of cane per hectare (TCH) and tons of Pol per hectare (TPH) in 20 sugarcane genotypes, with the goal of predicting the most probable capacity of each genotype and thus supporting the selection of genetically superior materials. The experiment was conducted in the experimental area of the Sugarcane Breeding Program in São Luiz do Quitunde, Alagoas, using a randomized block design with four replications and evaluating three harvests (2021, 2022, and 2023). Statistical analysis was performed using Analysis of Variance (ANOVA), which indicated a significant difference at the 1% probability level among genotypes for both traits, confirming the existence of genetic variability. The estimated genetic parameters revealed a high repeatability coefficient for TCH (0.61) and a moderate one for TPH (0.45). The determination coefficients were 82.26% and 71.29% for TCH and TPH, respectively. The optimization analysis showed that TCH is the most efficient criterion for selection, as it requires a significantly smaller number of measurements than TPH to ensure accuracy, thus reducing experimental cost and time. Finally, the most probable capacity and the mean comparison by the Scott-Knott grouping indicated the genotype RB15774 as the most promising for selection and advancement in the breeding program.