Fig. 3. Biplot of the SREG2 for four testers (T1, T2, T3, and T4) and 43 lines (1-43) across four acid soil environments. Lines 3-1 to 3-16 (underlined) are from population SA3, lines 4-17 to 4-19 and 4-22 to 4-35 are from population SA4, and lines 5-36 to 5-43 (bold) are from population SA5. The first digit of the line designation has been removed in the figure to avoid cluttering. The abscissa and the ordinate of the hypothetical average tester (AT) are marked with dot lines and the average value of PC1 and PC2 for AT is marked with a circle. The first and second multiplicative components are represented by PC1 and PC2, respectively.