First report of sweet potato feathery mottle virus infecting Amaranthus blitum in China

摘要

Sweet potato feathery mottle virus (SPFMV, genus Potyvirus) is the most common viral agent of cultivated sweet potato worldwide. SPFMV alone causes no or mild symptoms in most sweet potato cultivars, while the co-infection with sweet potato chlorotic stunt virus causes sweet potato virus disease (SPVD), the most serious disease in sweet potato globally (Clark et al. 2012). Weed species had previously reported to act as natural hosts for SPFMV (Tugume et al. 2008). In April 2019, seven plants of the three most common weed species, namely, Amaranthus blitum (four), Convolvulus arvensis (two) and Chenopodium album (one), were randomly collected in a field planting sweet potato seedlings in Xinxiang, Henan Province, China. SPFMV was tested in all samples by RT-PCR with a SPFMV-specific primer set (SPFMV-F1, 5′-TGGGGTTATGATGAACTTCTTC-3′; SPFMV-R1, 5′- TTCTGGAATGRYTGCGGGTTG-3′). An approximately 400-bp product of the expected size was obtained in one A. blitum plant displaying mottle symptoms on leaves and sequenced. The resulting 405-bp sequence was deposited in GenBank (accession No. MK953929) and analyzed by BLASTn, showing a 97.28 nucleotide sequence (nt) identity to SPFMV isolate TM64B (MF572053).