JING Chenchen, LUO Lu, HUO Sifan, WU Wenyan, WANG Xinhua, QING Ling, FENG Xue
As one of the major vegetable crops in Shanxi Province, tomato plants are constantly suffering from various virus infections, which severely limit tomato yield and quality. To determine the virus species and infection types on tomato plants, 154 samples exhibiting virus-like symptoms were collected from 7 cities and subjected to small RNA sequencing combined with PCR/RT-PCR for virus detection and identification. A total of six viruses were identified from these tomato samples. According to the detection rate from high to low, they were cucumber mosaic virus (CMV) (85.71%), tomato yellow leaf curl virus (TYLCV) (45.45%), southern tomato virus (STV) (41.56%), and tomato mosaic virus (ToMV) (27.27%), potato virus Y (PVY) (25.97%) and tomato chlorosis virus (ToCV) (18.18%). Among them, CMV was the dominant virus infecting tomato plants in Shanxi Province. Analysis of infection types showed that a total of 32 types were classified from the above samples, including 4 types of single virus infection and 28 types of mixed infection. Among them, CMV, CMV+ToMV, CMV+STV+TYLCV, CMV+PVY+STV, CMV+TYLCV, CMV+STV+ToCV+TYLCV and CMV+PVY were the most common types, with detection rates of 16.23%, 10.39%, 9.09%, 8.44%, 5.84%, 5.84%, and 5.19%, respectively and mainly exhibited mosaic, narrowing, chlorosis and leaf curling symptoms. Analysis of CMV satellite RNA (satCMV) association revealed that 66.23% of samples in 22 viral infection types were associated with satCMV, and samples in 10 infection types were partially associated with satCMV. Combined with the field symptoms, we found that CMV, CMV+ToMV and CMV+PVY+STV-infected samples showed severer symptoms, and CMV+STV showed milder symptoms in the presence of satCMV, and samples of other infection types exhibited no obvious symptom changes when associated with satCMV. Phylogenetic analysis showed that the pairwise identity of the 10 satCMV isolates from Shanxi was 93.4%-100%, and clustered with isolates from China and Greece. In this study, we identified 6 viruses and 1 satellite RNA in tomato plants in Shanxi Province, among which PVY and STV were reported in Shanxi tomato plants for the first time. And we comprehensively analyzed the relationship between virus infection types and field symptoms, providing an important reference for the rapid diagnosis and control of tomato virus diseases.