Early Growth Characterization and Antioxidant Responses of Phellodendron chinense Seedling in Response to Four Soil Types at Three Growth Stages

Soil type is an important environmental factor that affects plant growth and development, especially during the early growth stage. In this study, P. chinense (Phellodendron chinense) seedlings were cultivated on red soil (RS), yellow soil (YS), acidic purple soil (ACPS), and alkaline purple soil (ALPS), and the influence of soil types on the growth parameters and physiological responses at three growth stages were investigated. The results show that soil types and growth stages can significantly influence seedling height, base diameter, and biomass in P. chinense seedlings. Moreover, the significant variations in chlorophyll, total polyphenols, soluble protein, soluble sugar, and malondialdehyde (MDA) content, as well as superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia-lyase (PAL), and polyphenol oxidase (PPO) activity, were recorded at three growth stages among four soil types. These results show that P. chinense seedlings can grow normally in four soil types, and ACPS may be more beneficial for the artificial cultivation of P. chinense seedlings than those of RS, ALPS, and YS. Principal component analysis (PCA) reveals a strong correlation and clear differences in the test parameters between growth stage and organs in four soil types, and the cumulative contribution percentages of the total biplot range from 74.44% to 81.97%. This present information will be helpful for farmers in selecting soil type for the large-scale cultivation of P. chinense seedlings.