First Report of Tomato yellow leaf curl virus Associated with Beans, Phaseolus vulgaris, in Cuba.

Abstract

Beans with yellow mosaic and/or leaf crumple symptoms were collected in three fields in the southern area of the province of Havana, Cuba in December 2001 and February 2002. DNA was extracted from the fresh bean leaves of 25 samples (1). Dot blot hybridization was performed at high stringency with a specific probe for Tomato yellow leaf curl virus (TYLCV). The specific probe was prepared by alkaline phosphatase labeling of the polymerase chain reaction (PCR) fragment amplified with primer pair, PTYIRv21/PTYIRc287, containing the intergenic region (IR) of TYLCV, and chemiluminescent hybridization was completed as described by the manufacturer (AlkPhos Direct Labeling and Detection Systems, Amersham Pharmacia Biotech Inc., Piscataway, NJ). Four of the samples had positive hybridization signals. PCR was performed with overlapping primers for TYLCV (2) with the DNA extract from sample 01-44, which gave a positive hybridization signal with the TYLCV probe, and a 2.8-kb fragment was obtained. This fragment was cloned in pGem T-Easy (pBeTY44) and partially sequenced. Greater than 96% nt identity was obtained for the 591 nt of the IR and 504 nt of the N-terminus of the Rep gene with TYLCV (GenBank Accession No. AF260331). Also, PCR was completed on 11 of the 25 samples with the degenerate primer pair PAL1v1978/PAR1c715 for DNA-A (3). Eight samples gave fragment sizes of 1.4 kb and one sample gave a fragment of 1.3 kb. The 1.3-kb fragment from sample number 01-50 was cloned in pGem T-Easy (pBeBG50) and partially sequenced. Pairwise nucleotide comparisons with Bean golden yellow mosaic virus (BGYMV, GenBank Accession No. M91604) were 95% for 719 nt of the N-terminus of the Rep gene. These results are consistent with the association of both TYLCV and BGYMV in beans and have important implications for future disease management strategies.