Abstract: 【Aim】 This study aims to evaluate the changes in nutrients in tobacco induced by potato virus Y (PVY) and their effects on the life characteristics of the green peach aphid, Myzus persicae, so as to clarify the interaction mechanism between PVY-tobacco and aphids. 【Methods】 Changes in the soluble sugar and free amino acid contents in tobacco plants at different stages of PVY infection were determined using the anthrone colorimetric method and an automatic amino acid analyzer, respectively. The differences in population development parameters, adult longevity, fecundity, and the number of alataes of M. persicae on PVY-infected tobacco plants and healthy tobacco plants were investigated and compared. 【Results】 The free amino acid contents in tobacco leaves at the early, steady, and late stages of PVY infection (5, 12 and 20 d post infection, respectively) were significantly higher than those in the healthy leaves. Moreover, the contents of glutamic acid, proline, aspartic acid, tryptophan, valine, lysine, and histidine in tobacco leaves at the early stage of PVY infection were also significantly higher than those in the healthy plants. Moreover, at the steady stage of PVY infection, the serine content in tobacco leaves was significantly decreased, whereas the contents of glutamic acid, aspartic acid, tryptophan, valine, leucine, phenylalanine, arginine, and histidine were significantly increased as compared with those in the healthy leaves. At the late stage of PVY infection, the glycine content in tobacco leaves was significantly decreased, whereas the contents of glutamic acid, proline, aspartic acid, threonine, valine, leucine, alanine, phenylalanine, histidine, tyrosine, and arginine were significantly increased as compared with those in the healthy leaves. Furthermore, the soluble sugar contents in tobacco leaves at the early and steady stages of PVY infection were significantly higher than that in the healthy leaves, but significantly lower at the late stage of infection. The content ratios of total sugars to total free amino acids in tobacco leaves at the early and steady stages of PVY infection were significantly higher than that in the healthy leaves. Analysis of life table data showed that there were no significant differences in the developmental duration, pre-adult duration, reproductive period, post-reproductive period, longevity, intrinsic rate of increase, finite rate of increase and mean generation time of M. persicae on the PVY-infected and healthy plants. However, as compared with the aphids on the healthy plants, the aphids on the PVY-infected plants had a significantly shorter pre-reproductive period, and significantly higher fecundity and net reproductive rate. The M. persicae population on the PVY-infected plants showed an advanced peak of alatae emergence relative to that on the healthy plants. 【Conclusion】 The nutritional quality of tobacco host is improved at the early and steady stages of PVY infection, thus improving the fecundity of M. persicae. However, the decline in the nutritional quality of tobacco plants at the late stage of infection might contribute to the earlier emergence and spread of the alataes, which is conducive to PVY transmission.

Key words: Myzus persicae, Potato virus Y, tobacco, nutritional metabolism, life characteristics