First report of Sida golden yellow vein virus infecting Sida species in Cuba

Members of the genus Sida are common weeds in the Caribbean and Central America. Sida spp. plants with leaves showing yellow mottling have been commonly observed in Cuba. To identify the causal agent(s), symptomatic leaves from Sida plants were collected in the provinces of Havana, Santa Clara and Guantanamo between 1999 and 2001. Healthy Phaseolus vulgaris L. plants were inoculated using a biobalistic method (Finer et al., 1992) with total DNA extracts purified from infected leaves collected in Havana. Yellow mosaic and curling leaf symptoms were observed in 3 out of 15 inoculated bean plants. The presence of a begomovirus in both Phaseolus and Sida samples was shown by strong hybridization signals in Southern blots using DNA-A from Bean golden yellow mosaic virus-Cu as a probe, under high stringency conditions. Total DNA from the Havana Sida sample was further analyzed by PCR using two degenerate primer sets; PAL1v1978-PAR1c715 and PAL1c1960-PAR1v722 (Rojas et al., 1993). Amplicons of approximately 1.4 kb and 1.2 kb were amplified and cloned into pZero^TM-2.1 plasmid (Invitrogen, CA, USA) using standard procedures. Nucleotide sequences were compared to those from known begomoviruses using Clustal W analysis. For the coat protein (753 nucleotides (nt)) and rep genes (1080 nt), the highest percentages of identity (93.5 and 99% respectively) were to Sida golden yellow vein virus (SiGYVV, GenBank Accession No. U77964). In addition, the Cuban isolate (DNA-A 2600 nt) showed 97% nt sequence identity with SiGYVV-A. Common region (CR) analysis of SiGYVV-Cu A revealed 98% identity when compared to SiGYVV CR. Similar interons were identified in both viruses. These results confirm that the virus isolated from Sida plants in the province of Havana (GenBank Accession No. AJ 577395) is a strain of SiGYVV. This is the first identification of SiGYVV in Cuba.