Abstract:

Tomato leaf curl disease induced by begomoviruses pose a serious constraint to tomato production worldwide. Mixed infections in natural condition may cause recombination or pseudorecombination events and generated new virus strains，species or diseased complex that either intensify or ameliorate the severity of disease. In this study，two begomovirus isolates Y3080-32 and Y3080-40，and two betasatellite isolates Y3080-1 and Y3080-2，were obtained from a diseased tomato plant in Honghe，Yunnan Province，China，which shows leaf yellowing and stunting symptoms. Sequence comparison shows that Y3080-32 is highly related to Malvastrum yellow vein Honghe virus（MaYVHoV）that was reported previously to infect only Malvastrum coromandelianum，while Y3080-40 belongs to Pepper leaf curl Yunnan virus（PepLCYnV）. Recombination analysis reveals that the isolate Y3080-32 is  a recombinant begomovirus derived from MaYVHoV and PepLCYnV（Y3080-40）. In addition，this study shows that the betasatellite isolates of Y3080-1 and Y3080-2 are isolates of Malvastrum yellow vein betasatellite（MaYVB）. This report is a documentation of co-infection of MaYVHoV/MaYVB disease complex and PepLCYnV in tomato，and indicates mixed begomovirus infections provide opportunities for recombination and pseudorecombination events to occur.

Key words: begomoviruses, tomato leaf curl disease, betasatellite, mixed infection, recombination