*3.10. Determination of Interaction among Morpho-Physiological, Biochemical and Molecular Parameters through PCA*

The PCA was carried out to determine the degree of data variation and the relationship between the different treatments and parameters in both rice cultivars (Figure 6). The two components (PC1 and PC2) described 94.70% of data variability in Taipei-309 under the influence of different treatments (Figure 6). PC1, the first component, contributed 79.14% of the total variation, and the second component, PC2, accounted for 15.56% of the total variation. On the other hand, in the Rasi cultivar, the PCA showed 94.67% (PC1 = 78.83% and PC2 = 15.84%) data variance under the influence of different treatments (Figure 6. Shoot and root dry weight, SPAD value, parameters of chlorophyll fluorescence (ETR, qP, ΦPSII, Φesc, and Fv/Fm), net photosynthesis, intercellular CO2 concentration, stomatal conductance, photosynthesis-related genes (*psbA* and *psbB*), and RWC were grouped together and exhibited a positive correlation. Antioxidant enzymes (SOD, APX, and GR) and genes (*Mn-SOD*, *Cu-SOD*, *Fe-SOD*, and *APX*), contents of proline, GB, soluble sugars and trehalose, NO, and H2S content were grouped together and were also found to bepositively correlated with plant dry mass, chlorophyll fluorescence parameters, and photosynthesis parameters. However, H2O2 and TBARS, NPQ, and ethylene contents were grouped together and showed a negative correlation with other groups of parameters.
