Molecular Characterization of a Strain ofSquash Leaf Curl China Virusfrom the Philippines

The complete nucleotide sequence of infectious cloned DNA components (A and B) of the causal agent of squash leaf curl disease in the Philippines was determined. DNA‐A and DNA‐B comprise 2739 and 2705 nucleotides, respectively; the common region is 174 bases in length. Five ORFs were found in DNA‐A and two in DNA‐B. Partial dimeric clones containing DNA‐A and DNA‐B, constructed in a binary vector and transformed intoAgrobacterium tumefaciens, induced systemic infection in agro‐inoculated pumpkin plants (Cucurbita moschata). The total DNA‐A sequence was most closely related to that ofSquash leaf curl China virus(SLCCNV) (88% identity), although the existence of B component of SLCCNV has not been reported. The deduced coat protein was like that of SLCCNV (98% amino acid sequence identity) and the Philippines virus has low sequence identity toSquash leaf curl virus(SLCV) andSquash mild leaf curl virus(SMLCV) (63 and 64% total nucleotide sequence identities, respectively). From these results, we propose that the Philippines virus be designatedSquash leaf curl China virus‐[Philippines] (SLCCNV‐[PH]).