Objective This study aimed to analyze the agronomic traits and quality characteristics of Perilla frutescens (L.) Britton germplasm resources in southern China and to screen for superior materials, providing a theoretical basis for the breeding of functional perilla varieties in Fujian and similar ecological regions.

Methods VVariation analysis, correlation analysis, and principal component analysis (PCA) were employed to comprehensively evaluate 21 indicators, including agronomic traits, leaf color parameters, and nutritional and secondary metabolite components of 24 perilla accessions collected from six southern provinces.

Results The coefficients of variation (CV) for the 21 traits ranged from 2.36% to 202.83%, indicating abundant genetic diversity. The degree of variation in secondary metabolites (abaxial a* value, rosmarinic acid, and perillaldehyde) was significantly higher than that of basic nutritional components. Among agronomic traits, the 1000-grain weight exhibited the largest CV (56.52%), while the growth period showed the smallest (7.71%). Correlation analysis revealed that leaf morphological indicators (leaf length, leaf width, and petiole length) were highly significantly positively correlated with seed area and oil content, but highly significantly negatively correlated with perillaldehyde content and abaxial a* value (P ＜ 0.01). PCA extracted six principal components with a cumulative variance contribution rate of 84.15%. Based on the comprehensive score (F-value), four superior germplasm resources with scores ＞ 0.60 were identified. "Yunnan Husa Suzi" (A19) ranked highest (1.00), followed by "Sichuan Sumazi" (A23, 0.70). Additionally, "Yunnan Zisuma" (A22) exhibited the highest 1000-grain weight (3.57 g), while "Guangdong Zisu 4" (A8) possessed relatively high contents of both rosmarinic acid (0.66%) and perillaldehyde (0.31%).

Conclusion The 24 collected perilla germplasm accessions possess a rich genetic foundation. In general, the white perilla type P. frutescens (L.) Britton var. frutescens outperformed the purple perilla type P. frutescens (L.) Britton var. crispa (Thunb.) H. Deane in terms of vegetative growth and yield traits. The identified superior accessions demonstrate prominent phenotypic advantages and nutritional value in yield-related traits or key secondary metabolite contents, providing a scientific basis for germplasm screening and functional variety breeding in Fujian and similar ecological regions.