Distribution and identification of main Viruses Infecting Pepper in Qinghai.

From 2019 to 2021, pepper viruses were investigated in pepper planting areas and collected a total of 333 samples were in Qinghai (The central district, Datong, Huangzhong in Xining; Ledu district, Pingan, Huzhu, Minhe in Haidong, and Jianzha in Huangnan). RT-PCR and molecular cloning were conducted for virus detection in 333 suspected viral samples, the results revealed that viruses infecting pepper mainly included 11 capsicum viruses. Tomato spotted wilt tospovirus （TSWV）has the highest detection rate (36%) in Datong County, and Pepper cryptic virus 1 (PCV1) has the highest detection rate (57%) in Huangzhong County. In the Haidong, 86.3% of the peppers were Broad bean wilt virus 2（BBWV2）, virus-infected Pepper cryptic virus 2 (PCV2), TSWV and Cucumber mosaic virus （CMV） were detected in Xunhua, among which PCV1 and CMV had the highest detection rate (30.4%); PCV1, TSWV, and PCV2 were detected in Ledu and PCV2 had the highest detection rate (50%). There were 17 kinds of co-infection and the co-infection of two viruses occurred often. There were only 5 kinds of co-infection of three. Combined infection contained PCV1 and TMV was the most common. The distribution and species of pepper viruses from the pepper planting areas were clarified and it laid the foundation for preventing and controlling pepper viruses across Qinghai province.