Structure and site of the mutation in the <i>PcCesA3</i> gene associated with pyrimorph resistance.

<p>(A) Intron/exon structure of the <i>PcCesA3</i> gene. Numbers represent the size in base pairs. Point mutations in pyrimorph-resistant mutants (RF>50) and the predicted amino acid substitution in the mutant gene products are indicated. (B) Alignment of partial amino acid sequences of CesA3 in <i>P. capsici</i> (PcCesA3). Hd3, Hd11, Hx18, and Dz21 are wild-type isolates. R3-2, R3-3, and R11-1 are pyrimorph-resistant mutants. Mutations in pyrimorph-resistant mutants of <i>P. capsici</i> are indicated by asterisks.</p

Level and stability of pyrimorph resistance for the parental wild-type isolates and the resistant mutants of <i>Phytophthora capsici.</i>

a<p>Parent isolates were collected from the field locations. Mutants were obtained by mass selection on pyrimorph-amended medium.</p>b<p>EC₅₀ = effective concentration for 50% inhibition of mycelial growth at the 1^st transfer and the 10^th transfer.</p>c<p>RF = resistance factor, a ratio of EC₅₀ for a fungicide-resistant mutant relative to the EC₅₀ for the parental isolate.</p>d<p>FSC = the ratio of RF values at the 1^st and 10^th transfers.</p

Concentrations used to determine the sensitivity of wild-type isolates and pyrimorph-resistant mutants of <i>Phytophthora capsici</i> to various fungicides.

a<p>Concentrations used to determine the sensitivity of <i>Phytophthora capsici</i> mutants with high pyrimorph resistance to dimethomorph, flumorph, and mandipropamid respectively.</p

Fitness of pyrimorph-resistant mutants (mutant designations begin with the letter R) and the corresponding parental isolates of <i>Phytophthora capsici</i>^a.

a<p>Means in a column followed by the same letter are not significantly different at <i>p</i> = 0.05 according to Fisher’s least significant difference.</p>b<p>On carrot agar.</p>c<p>Lesion area and sporulation were determined on detached pepper leaves, and disease score was determined on growing pepper plants.</p>d<p>A disease severity scale of 0–5 was used: 0, no visible symptoms; 1, leaves slightly wilted with black lesions beginning to appear on stems or 10–29% of entire plant diseased; 2, 30–49% of entire plant diseased; 3, 50–69% of entire plant diseased; 4, 70–90% of entire plant diseased; 5, dead plant <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056513#pone.0056513-Kim1" target="_blank">[37]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056513#pone.0056513-Hartman1" target="_blank">[38]</a>.</p

Specificity of allele-specific PCR primers for detection of <i>Phytophthora capsici</i> mutants with high pyrimorph resistance.

<p>R3-2, R3-3, and R11-1 are mutants with high resistance to pyrimorph and were obtained by exposure to the fungicide on agar; isolates Hd3 and Hd11 are the corresponding parental isolates.</p

Frequency distribution of EC₅₀ values of <i>Phytophthora capsici</i> for pyrimorph.

<p>A total of 226 isolates of <i>P. capsici</i> were collected from 40 locations in 24 provinces of China; the locations had never been treated with pyrimorph. EC₅₀ represents the effective concentration causing 50% inhibition of mycelial growth of <i>P. capsici</i>.</p

Mycelial growth of <i>Phytophthora capsici</i> isolates and mutants on PDA as affected by temperature.

<p>(A, B, C, D) Isolates designated R3-X, R11-X, R18-X, and Dz-X are mutants of Hd3, Hd11, and Hx18, respectively, and were obtained by consecutive transfers on medium amended with pyrimorph. Values are means and standard errors. Colony diameters (minus plug diameters) were measured after 4 days of growth.</p