Fig. 7

Redundancy analysis (RDA) of different resistant Aster samples used 11 resistant indicators, and one environmental parameter. In the end, indicators with low contribution rates were deleted and only those with high contribution rates were retained for the final analysis. The red vectors in the graph indicate resistant indicators: peroxidase (POD), Polyphenol oxidase (PPO), Trypsin inhibitor (TI), Malondialdehyde (MDA), tannin (TN), total phenols (TP), and flavonoids (FN). The blue vectors indicate the environmental variables: insect population density (PD). (A–D) are the results of RDA analyses of highly resistant, moderately resistant, moderately susceptible, and highly susceptible types, respectively.