FIG. 2.

Southern blot analysis of periwinkle DNA. Chromosomal periwinkle DNA (12 μg) was digested with HindIII restriction enzyme, subjected to Southern blot hybridization, and probed with ³²P-labeled clone A1 (A) or with a 670-bp PCR product representing a conserved region of the tubulin gene (B). The size of the hybridization band is indicated on the left. The exposure time was 3 weeks (A) or 3 days (B). DNA was from healthy plants (lanes 1 and 2), from a Stolbur-infected plant (lanes 3), or from an AY-infected plant (lanes 4).