Abstract
Whitefly-transmitted begomoviruses (Family Geminiviridae) are the major pathogens of food and fiber crops and are often
associated with non-cultivated plants. In this study diversity of genomic components of begomoviruses associated with a weed
host Eclipta prostrata (E. prostrata) and viral infectivity were investigated. E. prostrata is often found besides the water
channels and agriculture fields in Pakistan, India, Vietnam and China. Plant leaves showing typical begomovirus symptoms
i.e., vein yellowing, were collected from different areas of the Punjab. Amplification of the full-length viral molecules and
associated satellite molecules was done through polymerase chain reaction (PCR) and rolling circle amplification (RCA)
followed by cloning and sequencing. Basic local alignment search tool (BLAST) analysis showed that Alternanthera yellow
vein virus (AlYVV) was associated with vein yellowing disease of E. prsotrata along with two different types of Alphasatellite
molecules. Sequence analysis showed that AlYVV is a new strain showing 95-98% sequence homology to AlYVV isolated
from India and China. Moreover this virus is a recombination free virus in all plant samples analyzed in this study. There was
no betasatellite molecule found associated with vein yellowing disease of E. prsotrata. In the infectivity analysis, infectious
molecules of the virus and associated alphasatellites were constructed. Infectious molecules of Tobacco leaf curl betasatellite
(TbLCB) and Cotton leaf curl Multan betasatellite (CLCuMB) which were constructed earlier, were included in this assay
together with AlYVV and its alphasatellites. Infectivity analysis showed that AlYVV is infectious to model host Nicotiana
benthamiana and viral movement was confirmed through Southern blot analysis. When both alphasatellites and betasatellites
were coinoculated with AlYVV, the movement of alphasatellites in systemic leaves was confirmed through PCR, however
betasatellites were not detected in the systemic leaves. So AlYVV might be betasatellite independent virus not supporting its
multiplication. The data presented in this paper would help in understanding the diversity and etiology of begomoviruses in
weed plants.
