Table 3. Mean GBLUP prediction accuracies for five combinations of switchgrass populations based on winter survival in either spring 2014 or 2015.

Population name	Number of families	Number of SNP markers	Spring 2014	Spring 2015
All Populations	368	434,919	0.88	0.91
All Lowland	257	400,699	0.87	0.77
Southern Lowland	168	204,636	0.17	0.43
Eastern Lowland	89	239,612	0.15	0.23
Lowland x Upland	111	95,397	0.20	0.02