| Abstract: In order to determine the effects of a new type of plant immune activating protein of Verticillium dahliae Asp-f2 Like (VDAL) on the growth traits of seedlings, quality and yield of lettuce, the effects of 2 500 times, 2 000 times, 1 500 times, 1 000 times and 500 times solution of wettable powder of VDAL, and 300 times solution of 6% oligosaccharides and chain protein on the growth of lettuce were studied, using loose leaf lettuce 'Dasusheng' as experimental material. The results showed that spraying VDAL
1 500 times solution and 1 000 times solution had obvious effects on strengthening seedlings and increasing production of lettuce. The highest VC content was 167.3 mg/kg after spraying VDAL 1 500 times solution, and the nitrate (NO3--N) content was lower than that of other treatments and significantly lower than that of VDAL 2 500 times solution. No nitrite (NO2--N) content was detected in all treatments. There was no significant difference in yield between different concentrations, but the yield of VDAL 2 500 times, 1 500 times, 1 000 times solution treatments was significantly higher than that of water control. In the production of lettuce, it was recommended to use VDAL 1 500 times solution. |