Variation in leaf morphology and architecture, phytochemical content, and antioxidant capacity among 36 Camellia sinensis clones of the Indian sub-Himalayan region

Abstract

Camellia sinensis, renowned as the second most widely consumed nonalcoholic beverage worldwide, bears substantial economic importance, prompting cultivators to breed various clones for enhanced flavor and quality. This study analyzed the variation in leaf phenotype, phytochemicals (total tannins and proanthocyanidins content) and antioxidant potential of 36 widely cultivated tea clones from India’s sub-Himalayan region using multivariate analysis. Results indicated that TV23 had the largest leaf and SS27 and RR had the smallest. TS520 was the richest in tannin, proanthocyanidins, and antioxidants, while S3A1 and Heeleakah were the least. Principal components analysis (PCA) and cluster analysis unveiled four morphological clusters (representative clones - TV1, TV23, TV30, 124.48.8) and four phytochemical clusters (representative clones - TS520, TV9, TV27, P126). GC-MS analysis revealed that TV1 and TV30 had high caffeine content (82.0%), while TS520 exhibited abundant antioxidant compounds, including sycllo-inositol (23.84%) and epigallocatechin (4.23%). TS520’s exceptional antioxidant properties, confirmed by DPPH, ABTS, and total antioxidant capacity assays, may result from its cultivation through seed propagation. Correlation analysis showed antioxidant potential had moderate negative associations with leaf size, strong negative with inter-secondary vein number, and positive with petiole length. This study is pivotal for assessing tea clone diversity, with broader applications in tea improvement and breeding programs.