STATISTICAL COMPARISONS OF MEANS OF SYNTHETIC VARIETIES OF MAIZE IN PREDICTIVE PHASE

Abstract

Field evaluation of the potential parents is required to predict the yield of the syntethic varieties that are possible to form with them; a statistical comparison of the means must provide to the plant breeder an objective basis to decide about the relative genotypic values of the different synthetics under consideration. Since the mean of a synthetic is estimated as a linear combination of several entry means, the typical procedures to compare individual entry means, such as Tukey and Duncan, are not applicable. In this study, specific methods to compare means of synthetic varieties on the basis of the information of two formulae of prediction of synthetic performance, are derived. It was found that both the number of parents and the number of common parents of the synthetic varieties under comparison, influence inversely the standard deviation of the difference of two experimental means of two synthetic varieties.