Prediction of maize single-cross performance by mixed linear models with microsatellite marker information

Abstract

ABSTRACT. We evaluated the potential of the best linear unbiased predictor (BLUP) along with the relationship coefficient for predicting the performance of untested maize single-cross hybrids. Ninety S 0:2 progenies arising from three single-cross hybrids were used. The 90 progenies were genotyped with 25 microsatellite markers, with nine markers linked to quantitative trait loci for grain yield. Based on genetic similarities, 17 partial inbred lines were selected and crossed in a partial diallel design. Similarity and relationship coefficients were used to construct the additive and dominance genetic matrices; along with BLUP, they provided predictions for untested single-crosses. Five degrees of imbalance were simulated (5, 10, 20, 30, and 40 hybrids).The correlation values between the predicted genotypic values and the observed phenotypic means varied from 0.55 to 0.70, depending on the degree of imbalance. A similar result was observed for the specific combining ability predictions; they varied from 0.61 to 0.70. It was also found that the relationship coefficient based on BLUP provided more accurate predictions than similarity-in-state predictions. We conclude Prediction of maize single-cross hybrids that BLUP methodology is a viable alternative for the prediction of untested crosses in early progenies.

Prediction of maize hybrid performance using similarity in state and similarity by descent information

“…Moreover, in ideal situations, such as those obtained by Bernardo (1994Bernardo ( , 1995, where two distinct heterotic groups are evident, the predictions using the SBD tend to be more accurate and consistent with the observed values. These results were also observed by Balestre et al (2010). However, if distinct groups do not occur and the inbred lines come from different backgrounds the level of information retrieved using the SBD may be minimal and lead to less accurate predictions, as occurred in this study.…”

“…This fact was also observed in several studies where the variance of GCA was higher than the variance of SCA and in these cases, as expected, the predictions were assisted. In this study, although the variance of SCA was greater than the variance of GCA, the difference between the two variances was less pronounced as observed by Balestre et al (2010). Even in this case, the authors observed medium magnitude correlation values between the predicted and observed values.…”

“…Using the BLUP in the prediction of unanalyzed hybrids has been recommended by many authors (Bernardo, 1994(Bernardo, , 1995(Bernardo, , 1996aCharcosset et al, 1998;Schrag et al, 2009, Balestre et al, 2010. In this context, the use of molecular marker information is an alternative when the pedigrees of the parents are unavailable, contributing to the obtaining of more accurate predictive estimates of the genotypic values of untested hybrids.…”

“…An alternative to the use of information obtained by molecular markers would be the use of this information through the methodology of linear mixed models for prediction of unrealized crosses (Bernardo, 1994;Charcosset et al, 1998;Schrag et al, 2009, Balestre et al, 2010. To do this, it becomes necessary to know the genealogy or the relatedness between the individuals evaluated and individuals in which their performance needs to be predicted (Bernardo, 1994).…”

Prediction of maize double-cross hybrids using the best linear unbiased prediction with microsatellite marker information

“…The efficiency of this approach has been demonstrated in several studies of maize (Bernardo, 1994(Bernardo, , 1995(Bernardo, , 1996Schrag et al, 2009;Balestre et al, 2010). In all these studies, a relatively good correlation between phenotypic means and predicted means was observed, demonstrating acceptable accuracy.…”