Fig. 4
GWAS of phenolic compounds within and across 67 cultivated and 156 Tibetan wild subgroups. Three grain parameters were applied to indicate content of phenolic compounds: TPC (△), FLC (+) and TPC (×). GWA analysis was firstly conducted using three different methods: Q, K and Q + K methods. Then, Q + K method was selected to perform GWA analysis in cultivated and Tibetan wild subgroups individually. Dashed lines presented different p value of the four markers (bPb-4531, bPb-1068, bPb-0572 and bPb-3227) associated with these three parameters in wild and cultivated barley genotypes. Significant associations were identified using criterion of -log10(P) > 2 or 3