Fig. 1a shows the score plot of the first two PCs which accounted
for 45.14% of total variance in raw data (PC1 = 27.78% and
PC2 = 17.36%). The percentage of variance for PC3, PC4, and PC5
was 10.61%, 8.63% and 6.78%, respectively. The low percentage explained
by the first several PCs could be attributed to the diversity
of samples.