FIRST REPORT OF PEPPER CRYPTIC VIRUS 2 INFECTING PEPPER IN CHINA

Abstract

Pepper cryptic virus 2 (PCV-2) is a double-stranded RNA virus which belongs to the genus Deltapartitivirus in the family Partitiviridae (Nibert et al., 2014; Sabanadzovic and Valverde, 2011). PCV-2 was previously reported infecting pepper in the USA and India (Saritha et al., 2016). In 2015, twenty pepper (Capsicum annuum L.) plants showing mosaic, crinkle and stunting symptoms were collected in Chongqing and used to detect potential viruses by high throughput sequencing using the Illumina HiSeq 2000 platform. Small RNA sequences between 18 and 26 nt in size were assembled and aligned. Five and three contigs were mapped to the double-stranded RNA1 and RNA2 of PCV-2 respectively. The primers PCV2-R1F (5’-AGAATTTTCCAAGCCGTTTACTT-3’)/ PCV2-R1R (5’-GATTAAGCTTCCAATTCAATGGT-3’) and PCV2-R2F (5’- AGAGCGGTGTGTTGGCAG-3’)/PCV2-R2R (5’-TAGTGCCTTATGCCCAAT-3’), designed in RNA-1 and RNA-2 of PCV-2 were used to confirm the presence of PCV-2 in pepper samples by RT-PCR. The partial nucleotide sequence of RNA1 (KX905077) and RNA2 (KX905078) obtained from PCV-2 isolate BB13 consisted of 1245 nt and 1487 nt, and shared highest identity of 97.1% and 99.8% with isolate HW-01 (JN117278) and ChS1 (KR676354), respectively. Nine out of the 20 samples that were tested by RT-PCR with specific primers HW-1/HW-1R (Sabanadzovic and Valverde, 2011) were positive for PCV-2. The high throughput sequencing data showed the occurrence of additional putative viruses such as Cucumber mosaic virus (CMV) in pepper. Therefore, symptoms could not be attributed only to PCV-2. To our knowledge, this is the first report of PCV-2 infecting pepper in China.