Figure 4.

Detection of viral DNAs in A. conyzoides plants. Samples (5 μg of nucleic acids) were extracted from individual plants infected either by agroinoculation with DNA A and DNA β (lanes 1 and 2; sampled 26 days p.i.) and DNA A alone (lane 4; sampled 42 days p.i.) or by whitefly transmission of the cloned progeny of DNA A and DNA β (lane 3; sampled 13 days after insect transmission) and DNA A alone (lane 5; sampled 23 days after insect transmission). A sample from a symptomatic plant (1/10 of the sample in lane 1) has been included as a marker (lane M) to allow comparison of the relative levels of DNA A in symptomatic and asymptomatic plants. Samples were fractionated by using agarose gels in TNE buffer, and blots were screened by using probes specific for DNA A (Upper) and DNA β (Lower). The position of single-stranded DNA (ss) is shown.