Figure 6.

Nonmechanically transmissible viruses fail to accumulate to detectable levels in plants after sap inoculation. (a) Southern blot analysis of viral DNA in the open circular (oc), supercoiled (sc) double‐stranded DNA, and single‐stranded DNA (ss) forms in the cotyledons of oriental melon mechanically inoculated with infectious clones as indicated over time (0, 5, 10, and 14 days post‐inoculation, dpi using the tomato leaf curl New Delhi virus (ToLCNDV)‐OM MP probe. DNA prepared from oriental melon inoculated with pCB2A + pCB1B (upper panel) or pOM2A + pOM1B (lower panel) by using Agrobacterium was used as a positive control. DNA stained with ethidium bromide was used as the loading control. (b) In situ hybridization of Nicotiana benthamiana leaves with the ToLCNDV‐OM MP probe at 5 dpi with the infectious clones, as indicated. The dark spots observed in samples inoculated with pCB2A + p pCB1B_{MP (19G→E)} and pOM2A + pOM1B represent viral hybridization signals. Bar = 100 μm. Only representative examples are shown