Molecular identification and sequence analysis of tomato spotted wilt virus and tobacco mosaic virus on Artemisia caruifolia
Tomato spotted wilt virus(TSWV)and tobacco mosaic virus(TMV)are two important viral pathogens that account for significant yield losses and quality damage in many economically important crops.During 2021-2022,14 sweet wormwood(Artemisia caruifolia)leaf samples with leaf yellowing and curling symptoms or asymptomatic were collected from tobacco fields in Lijiang of Yunnan province.The colloidal gold antigen rapid screen kits and RT-PCR were used to identify the pathogens of diseased plants.Immunological assays using colloidal gold antigen rapid screen kits showed that nine leaf samples were infected with TSWV(64.28%positive rate),three infected with TMV(21.43%positive rate),and three infected with both TSWV and TMV.RT-PCR was carried out to obtain viral sequences from these three co-infected sweet wormwood samples.Then three N gene sequences of TSWV,three cp sequences and two partial RdRp sequences of TMV were obtained.Sequence alignment showed that the TSWV isolates were most closely related to the TSWV-2 isolate from Yunnan sharing 99.6%sequence identity,and the TMV isolates shared the highest sequence identity(>99.4%)with the Shenyang isolate from Liaoning and Yongren-1 isolate from Yunnan.It is the first report that sweet wormwood plants were co-infected by TSWV and TMV.