Detection Of PMMoV In Pepper And Identification Of Viruses In Jujube

Plant viral disease is a kind of important disease of crops. Due to their diversities, wide spread ways and lack of effective control measures, plant viral disease would cause heavy losses to agricultural production once it is prevalent. Identification of virus species and spread ways are the key steps to control viral diseases. In view of this, this study focused on the detection of Pepper mild mottle virus (PMMoV) in pepper and identification of viruses in jujube trees (Ziziphus jujube Mill.). Distribution and spread ways of PMMoV were determined and some possible viruses were identified from jujube, which provide a theoretical basis for prevention and control of associated viral diseases.Symptoms of pepper infected with PMMoV include leaf shrinking and fruit decrescence, which reduce the yield of pepper production, and more importantly, it is the first known plant virus that could endanger human health. Here, a total of 249 fresh pepper fruit samples and 7 various kinds of pepper processed products were collected from different provinces in China and the incidence of PMMoV was detected using RT-PCR. Results showed that PMMoV was detected in 188/249 of fresh pepper fruit samples and 97/147 of pepper processed product samples. Furthermore, PMMoV was detected in all tested different kinds of pepper processed products. These results suggested that PMMoV has been widely distributed in pepper fruits and its processed products in China, and infection rates were high (75.5%). Existence of PMMoV in pepper deep-processing products (such as Chinese pickles and pickled cabbages) confirmed the stability of PMMoV particles, so we concluded that PMMoV can enter human body through direct consumption of pepper or its processed products and become a new source of infection with the feces discharge. In this study, origin and possible spread ways of PMMoV were determined, which provide a theoretical basis for the effective control of this virus.As the dominant tree species with national characteristics, jujube has aroused general interest with the development of fruit trees in China. Till now, there is no virus reported in jujube, and here, some possible viruses were identified in jujube. Leaf samples were collected from a jujube tree aged 200, and virus identification was conducted by high-throughput sequencing. Several types of Badnavirus were detected, and one of them was sequenced, which is named Jujube badnavirus 1 (JBV-1) temporarily. JBV-1,6461bp in size, is a circular double-stranded DNA, and its genome encodes seven open reading frames (ORFs) on the plus strand, including three conserved ORFs i.e. ORF1, ORF2, and ORF3. ORF 1 and 2 encodes two different small proteins, and ORF 3 encodes a large polyprotein. Phylogenetic tree analysis based on full-genome sequence showed that JBV-1 and other badnaviruses were into a single cluster, and JBV-1 was more closely related to PVBV. In conclusion, viruses were identified in jujube for the first time in this study, and all the results laid the foundation for further research on biological characteristics of jujube viruses and provided basic data for understanding the epidemic and spread of jujube viral diseases in China.