Natural association of two different betasatellites with Sweet potato leaf curl virus in wild morning glory (Ipomoea purpurea) in India

Abstract

Wild morning glory (Ipomoea purpurea) was observed to be affected by leaf curl and yellow vein diseases during summer-rainy season of 2009 in New Delhi, India. The virus was experimentally transmitted through whitefly, Bemisia tabaci to I. purpurea that reproduced the two distinct symptoms. Sequence analysis of multiple full-length clones obtained through rolling circle amplification from the leaf curl and yellow vein samples showed 91.8-95.3% sequence identity with Sweet potato leaf curl virus (SPLCV) and the isolates were phylogenetically distinct from those reported from Brazil, China, Japan and USA. Interestingly, two different betasatellites, croton yellow vein mosaic betasatellite and papaya leaf curl betasatellite were found with SPLCV in leaf curl and yellow vein diseases of I. purpurea, respectively. This study is the first report of occurrence of SPLCV in wild morning glory in India. SPLCV was known to infect other species of morning glory; our study revealed that I. purpurea, a new species of morning glory was a natural host of SPLCV. To date, betasatellite associated with SPLCV in Ipomoea spp. is not known. Our study provides evidence of natural association of two different betasatellites with SPLCV in leaf curl and yellow vein diseases of I. purpurea.