Papaya Leaf Curl Guangdong Virus and Ageratum Yellow Vein Virus Associated with Leaf Curl Disease of Tobacco in China

Two samples (YC7, YC27) of Nicotiana tabacum showing leaf curling, vein swelling and enations on undersides of leaves were collected in the Fujian Province of China in 2007. Virus isolates YC7‐1 and YC7‐2 (associated with betasatellite, YC7‐2β) were detected in both samples. The complete DNA‐A sequence of YC7‐1 (FJ869907) comprised 2741 nucleotides (nt). The complete DNA‐A (FJ869908) and betasatellite (FJ869909) sequence of YC7‐2 consisted of 2754 and 1344 nt, respectively. YC7‐1 had the highest nucleotide sequence identity (97.3%) with Papaya leaf curl Guangdong virus (PaLCuGuV‐CN:Gd2:02], AJ558122). YC7‐2 had the highest sequence identity (90.1%) with Ageratum yellow vein virus (AYVV‐TWTW:Tai:99], AF307861) and its betasatellite (96.5%) with Ageratum yellow vein betasatellite (AYVB‐TW:CHu:02], AJ542495). These indicate that YC7‐1 and YC7‐2 are isolates of PaLCuGuV and AYVV, respectively. Symptoms including leaf curling, vein swelling and enations on undersides of leaves were observed in N. tabacum and N. glutinosa when infected by whiteflies with sample YC7 as the viral source under greenhouse conditions. PCR results showed that these infected plants contained both YC7‐1 and YC7‐2/YC7‐2β. To our knowledge, this is the first report of PaLCuGuV and AYVV/AYVB co‐infecting N. tabacum in China.