Molecular characterization of a distinct begomovirus species and its associated satellite DNA isolated from Malvastrum coromandelianum in China.

A virus isolate Y160 was obtained from Malvastrum coromandelianum showing yellow vein symptoms in Baoshan, Yunnan province of China. The complete nucleotide sequence of DNA-A was determined, it contains 2747 nucleotides and has typical genomic organization of a begomovirus. Comparisons show that the total DNA-A of Y160 has the highest sequence identity (82.2%) with that of Malvastrum yellow vein virus-[Y47] (AJ457824), while less than 77.6% identities are found when compared with the other begomoviruses. The molecular data show that Y160 is a distinct begomovirus species, for which the name Malvastrum yellow vein Yunnan virus (MYVYNV) is proposed. Satellite DNA molecule (Y160beta) was found to be associated with Y160 using the abutting primers beta 0l and beta 02 specific for DNA beta. Y160beta consists of 1350 nucleotides, with a functional ORF (beta C1) in complementary-sense DNA. Y160beta has the highest sequence identity (73.5%) with DNA beta molecule associated with Malvastrum yellow vein virus-[Y47] (AJ421482).