Abstract: The development of dual-purpose tea resource is especially important for the structural adjustment and efficiency improvement of tea industry. Thus, it is essential to comprehensively characterize the seed-related traits from current available tea germplasms, which can be used to guide dual-purpose tea genetic improvement. In this study, tea seeds of the same year were collected from 31 germplasms grown in Fujian, Yunnan, and Hunan, seed oil contents and compositions were analyzed. We found that there were more than two-fold variations in seed oil content. Ten different fatty acids were detected from tea seed oil, including palmitic acid, palmitoleic acid, 11(Z)-hexadecenoic acid, stearic acid, oleic acid, 11(Z)-octadecenoic acid, linoleic acid, linolenic acid, arachidic acid, and eicosanoid acid. Oleic acid was the dominant component of tea seed oil, which accounted for 42.1%-59.2% of the total fatty acids, followed by linoleic acid (18.9%-32.8%). Saturated fatty acid accounted for 15.9%-20.8% of the total fatty acids, with palmitic acid as the dominant component. Feature analysis of fatty acid composition indicates that there were large variations of the FAD2 and FAD3 activities among these germplasms. Based on these findings, the methods to select parent lines for dual-purpose tea breeding were discussed.

Key words: tea seeds, oil content, fatty acid, fatty acid desaturase