Abstract: Fresh leaf quality of tea can be improved under the intercropping mode in tea gardens, partly due to the changes in light intensity and light quality received by tea trees. To explore the effects of shading and light quality treatments on photosynthesis and tea quality in tea plants, we established an experiment in an artificial climate chamber with five light treatments: white light (CK), blue light (BL), red light (RL), 60% shade (60-S) and 90% shade (90-S). We examined the effects of light intensity and light quality variations on tea quality. The results showed that short-term red light treatment enhanced net photosynthetic rate and the contents of free amino acids and water extracts in leaves, while the contents of photosynthetic pigments, free amino acids and caffeine increased under blue light treatment. In addition, short-term red and blue light treatments promoted the relative contents of aromas such as (Z)-3-Hexen-1-ol and trans-2-hexenal in leaves. Short-term shading treatment was beneficial for increasing the contents of photosynthetic pigments, free amino acids and water extracts, while decreasing the contents of tea polyphenols and flavonoids, and enhancing the relative contents of aroma components such as 2-ethylhexanol, methyl salicylate and β-pinene. Proper shading, which reduces light intensity and alters light quality, can therefore improve tea quality.

Key words: tea leaf, light intensity, light quality, tea flavor, tea fragrance