Evolution of CMV seed transmission, virus accumulation and virulence across passages of vertical transmission.

<p>Seed transmission rate (<b>A</b>) was estimated from the number of infected seedlings out of 100 seeds per plant. Virus accumulation (<b>B</b>) was measured as µg of viral RNA per g of fresh leaf tissue. Virulence (<b>C</b>) is represented as one minus the ratio of seed weight in infected to mock-inoculated plants: 1−(<i>SW</i>_i<i>/SW</i>_m). Data are plotted as mean±standard error of the five independent lineages in each passage for Fny-CMV (blue squares), De72-CMV (red triangles) and LS-CMV (green diamonds). The black line in each panel represents the fitted regression line for lineages of all three strains combined.