The distribution of catechins and their derivatives among 114 Camellia plants and their correlation in different species and tea-processing suitability

China is rich in tea germplasm resources. Catechins and their derivatives were analyzed regarding their associations among species and tea-processing suitability using 114 representative Camellia plants. GCG, ECG, EGC, ECG3″Me, and EGCG were revealed as potentially useful markers for identifying different tea species, while three O-methylated catechins may be appropriate markers for determining the tea-processing suitability of oolong tea. A correlation analysis indicated that the EGCG3″Me content was significantly higher in varieties suitable for oolong tea than in varieties suitable for black and green teas. Catechin (C, GC, CG, and GCG) contents were significantly higher in Camellia ptilophylla Chang than in Camellia sinensis var. sinensis, Camellia sinensis var. assamica, and Camellia sinensis var. pubilimba Chang. Furthermore, 14 specific tea tree resources with a high catechin index and high EGCG, GCG, and EGCG3″Me contents were screened. This research enhances our understanding of associations among catechins and tea germplasm resources.