Predicting Genetic Variance from Genomewide Marker Effects Estimated from a Diverse Panel of Maize Inbreds

Predicting the genetic variance (V-G) in a biparental population has been difficult. Our objective was to determine whether the population mean, V-G, and mean of the top 10% of progeny in a cross can be predicted effectively from genomewide marker effects estimated from a diverse panel of inbreds. Eight maize (Zea mays L.) crosses that differed in their predicted mean and V-G were evaluated for plant and ear height and growing degree days to silking. Each cross was represented by 120 to 144 random F 3 lines that were evaluated in balanced experiments at three locations in Minnesota in 2017. Correlations between the observed and predicted means of each breeding population were significant (r >= 0.80, P = 0.05) for all three traits. However, correlations between the observed and predicted V-G were nonsignificant (-0.24 to 0.14) for the three traits. Correlations between the observed and predicted mean of the top 10% of progeny in each cross were significant (P = 0.05) for plant height (0.72), but not for ear height and silking date. These results for predicting the mean of the top 10% of progeny reflected the ability to predict the mean but not V-G. We concluded that the mean, but not the V-G, of biparental crosses can be effectively predicted from genomewide marker effects estimated from a diverse panel of inbreds.