PRECISION AND BIAS ESTIMATORS OF MEANS DIFFERENCES OF MEDIAN COMPLEMENTARY SYNTHETICS

Abstract

The method of evaluation of the parental value of genetic materials consisting in the assessment of their performance in median complementary synthetics (MCS), which is accomplished by testing a family from each material, allows the evaluation of a high
number (N) of candidates to build up synthetic varieties. In order to contribute to the characterization of the method of median complementary synthetics (MMCS), an unbiased estimator of the difference between two MSC means is developed; its precision
is compared against the precision obtained with estimators from the methods proposed by Wright (MW) and Márquez-Sánchez (MMS). Based on the variance of the estimators, it was found that MMS was the most precise method and the MW was intermediate. However, when N is larger than 16, only the MSCM can be reasonably applied because of its lower number of entries. When the comparison of the precision was made under the same number of experimental units for each method, the variance for the MW was the lowest.