Micromorphological characterization of leaf epidermis in Camellia sinensis (L.) Kuntze accessions using light and scanning electron microscopy

Tea ( Camellia sinensis (L.) Kuntze) accessions often exhibit high morphological similarity, making discrimination based solely on macromorphological traits difficult. Although leaf epidermal anatomy and micromorphology have taxonomic significance in C. sinensis , comparative studies among Darjeeling tea accessions remain limited. Therefore, the present study aimed to evaluate the leaf epidermal anatomical and micromorphological diversity of 36 abundantly cultivated tea accessions of Darjeeling grown under uniform environmental conditions using light microscopy, scanning electron microscopy, and multivariate analyses. Epidermal cell morphology, anticlinal wall patterns, stomatal characteristics, and trichome morphology and density were investigated. All accessions exhibited hypostomatic leaves with stomata restricted to the abaxial surface, while anisocytic and anomocytic stomatal complexes predominated. Variations in anticlinal wall patterns, stomatal dimensions, stomatal index, and trichome density were observed among accessions. Multivariate analyses further revealed distinct grouping patterns based on combined epidermal traits. Accessions such as Sundaram, TV18, and TV17 formed a closely related cluster due to their comparatively higher stomatal trait values, whereas TV29, TV22, Teenali, and Tukdah 383 clustered together because of their relatively lower stomatal parameters. The findings demonstrate that leaf epidermal anatomical and micromorphological traits can serve as valuable markers for distinguishing closely related tea accessions and establish a comparative baseline dataset for germplasm characterization, accession identification, and future investigations assessing environmental and climatic influences on tea leaf epidermal traits.