In this study, effects of continuous cropping on soil properties, enzyme activities, and relative abundance, community composition and diversity of fungal taxa were investigated. Rhizosphere soil from field continuously cropped for one-year, three-year and five-year by Coptis chinensis Franch. was collected and analyzed. Illumina high-throughput sequencing analysis showed that continuous cropping of C. chinensis resulted in a significant and continuous decline in the richness and diversity of soil fungal population. Ascomycota, Zygomycota, Basidiomycota, and Glomeromycota were the dominant phyla of fungi detected in rhizosphere soil. Fungal genera such as Phoma, Volutella, Pachycudonia, Heterodermia, Gibberella, Cladosporium, Trichocladium, and Sporothrix, were more dominant in continuously cropped samples for three-year and five-year compared to that for one-year. By contrast, genera, such as Zygosaccharomyces, Pseudotaeniolina, Hydnum, Umbelopsis, Humicola, Crustoderma, Psilocybe, Coralloidiomyces, Mortierella, Polyporus, Pyrenula, and Monographella showed higher relative abundance in one-year samples than that in three-year and five-year samples. Cluster analysis of the fungal communities from three samples of rhizosphere soil from C. chinensis field revealed that the fungal community composition, diversity, and structure were significantly affected by the continuous cropping. Continuous cropping of C. chinensis also led to significant declines in soil pH, urease, and catalase activities. Redundancy analysis showed that the soil pH had the most significant effect on soil fungal population under continuous cropping of C. chinensis.

Styphnolobium japonicum (L.) Schott is widely cultivated in China, and its flowers and flower buds (FFB‐SJ) are commonly used as traditional Chinese medicine. This work aimed to assess variations in the chemical components and antioxidant and tyrosinase inhibitory activities of S. japonicum extract during five flower maturity stages (ES1–ES5). The results showed that the contents of total flavonoids, rutin, and narcissin were highest at ES1, whereas the contents of quercetin and isorhamnetin were highest at ES3. ES1 presented considerable antioxidant activities in terms of reducing power (RP) and 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH.) and hydroxyl radical (.OH) scavenging capacity, whereas ES3 showed excellent tyrosinase inhibitory activity and 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) radical (ABTS.+)‐ and O2.−‐scavenging capacity. Rutin and quercetin are the main bioactive components of FFB‐SJ with antioxidant and tyrosinase inhibition, and the immature flower buds of S. japonicum (S2 and S3) with excellent biological activities and relatively high extract yields were the best for product development.

Sophora japonica L. is widely consumed in China because of its medicinal and nutritional value. Its quality is greatly affected by the accumulation of metabolites, which varies with the stage of flower development. However, changes in the characteristics of the secondary metabolites during flower maturity remain unclear. Ultra-high-performance liquid chromatography coupled with electrospray ionization-triple quadrupole-linear ion trap mass spectrometry (UPLC–ESI–QTRAP–MS/MS) revealed dynamic changes in the secondary metabolites of S. japonica during the five flower-maturity stages. We monitored 331 metabolites and screened 164. The differential metabolites showed seven trends during flower maturation, with flavonoids and phenolic acids having the most varied expressions. Flower buds (S2–S3) are rich in flavonoids and are thus suitable for use in high-quality medicine or industrial extraction. Our study provides an empirical basis for the informed harvesting of S. japonica based on its mode of utilization.

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