PCA of phenotypic data. Biplot of principal component (PC) analysis of inbred - heat level means for six traits of eight inbred lines examined at three heat levels. Numbers in parentheses represent the percentage of total variance explained by the first and second PC. Yellow and red colors represent Flint, and blue represents Dent inbred lines. The shapes (circle, square, triangle) represent the studied heat levels (25, 32 and 38°C).