两种菜豆金色花叶病毒属病毒复合侵染番茄及重组特征

由菜豆金色花叶病毒属病毒引起的番茄曲叶病严重制约着世界范围内番茄的生产。自然条件下复合侵染引起的重组或假重组可能产生新株系、新种或新的病害复合体，导致致病性增强或减弱。从云南红河地区表现叶片黄化并伴随植株矮化的一株番茄中，获得了Y3080-32和Y3080-40两个菜豆金色花叶病毒属病毒分离物以及Y3080-1和Y3080-2两个beta卫星分离物。序列比对表明，Y3080-32属于红河赛葵黄脉病毒（MaYVHoV）分离物，Y3080-40属于云南辣椒曲叶病毒（PepLCYnV）分离物。重组分析显示，分离物Y3080-32是重组病毒，由MaYVHoV和PepLCYnV（Y3080-40）重组产生。Y3080-1和Y3080-2是赛葵黄脉beta卫星（MaYVB）分离物。MaYVHoV/MaYVB复合体和PepLCYnV复合侵染番茄，表明菜豆金色花叶病毒属病毒的复合侵染为重组和假重组的发生提供了机会。

Recombination and Mixed Infection of Two Distinct Begomoviruses in Tomato

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.