Abstract: In order to explore the differences in leaf color and volatiles of different insect-resistant tea cultivars, a two-year field population density survey was conducted on 11 tea cultivars. Through the indoor incubation test of field branches and the indoor life parameter determination test, the reliability of field population density as the resistance grading standard was proved. The color difference and wax content per unit leaf area of leaves were determined, and the volatiles of new shoots of one bud and two leaves that were not harmed by pests and diseases were detected by gas chromatography-mass spectrometry (GC-MS) in order to screen the differences among different insect-resistant tea cultivars. The results show that, M. onukii preferred tea cultivars with darker, lighter yellow leaves. D minowai preferred tea cultivars with brighter, more saturated colors and a higher yellow color, and D minowai placed more emphasis on the color of the leaf back. In terms of volatiles, the population densities of M. onukii were significantly and positively correlated with the relative content of linalool and negatively correlated with the relative contents of nonanal and dodecane. Population densities of D. minowai were significantly and positively correlated with the relative levels of dodecane and phenylethanol. The effects of dodecane on M. onukii and D. minowai were opposite, and the same trend was observed for the relationship between wax and population density in tea leaves, suggesting that the same volatile substance may have different reactions to different insects.

Key words: tea plant, Matsumurasca onukii, Dendrothrips minowai, leaf color, volatile components, resistance