Structure and site of mutation in the <i>PmCesA3</i> gene associated with carboxylic acid amide (CAA) fungicide resistance.

<p>(A) Intron/exon structure of the <i>PmCesA3</i> gene. Numbers represent the size in base pairs. Point mutations in CAA-resistant mutants 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. melonis</i> (PmCesA3), <i>P. infestans</i> (PiCesA3), and <i>P. viticola</i> (PvCesA3). TJ-90, TX-21, and TX-33 were wild-type isolates. D63-1 and D70-3 were dimethomorph-resistant mutants. F58-4 and F63-11 were flumorph-resistant mutants. I63-2 and I70-5 were iprovalicarb-resistant mutants. Mutations in CAA-resistant mutants of <i>P. infestans</i>, <i>P. viticola</i> and <i>P. melonis</i> are indicated by asterisks.</p

Fitness of CAA-resistant and -sensitive isolates of <i>Phytophthora melonis in vitro</i>.

a<p>Isolates in bold font are parents of the resistant isolates listed under them in regular font. Isolates starting with the letter F, D, and I, are flumorph-resistant mutants, dimethomorph-resistant mutants, and iprovalicarb-resistant mutants, respectively.</p>b<p>For each parent and its resistant progeny, means followed by same letters are not significantly different according to Fisher’s least significance difference (α = 0.05).</p>c<p>CFI (compound fitness index)  =  mycelial growth × zoospore production × lesion area on cucumber leaves.</p

Isolates of <i>Phytophthora melonis</i> used for RAPD analysis and their sensitivities to flumorph, dimethomorph and iprovalicarb.

a<p>One isolate of <i>Phytophthora drechsleri</i> was used as an outgroup control.</p>b<p>EC₅₀ values, the effective concentration for causing 50% inhibition of mycelial growth inhibition of <i>P. melonis</i>.</p>c<p>Number represents a different field in the same district.</p

Frequency distributions of EC₅₀ values (the effective concentration causing 50% inhibition of mycelial growth of <i>Phytophthora melonis</i>) for flumorph, dimethomorph and iprovalicarb.

<p>In total, 80 isolates of <i>P. melonis</i> were collected from areas never exposed to carboxylic acid amide fungicides.</p

Results of the experiments conducted to induce resistance against flumorph, dimethomorph, and iprovalicarb in <i>Phytophthora melonis</i>.

a<p>SM, spontaneous mutation. UV, UV-mutagenesis.</p>b<p>Survival frequency, number of mutants/total number of zoospores used for mutant generation.</p>c<p>EC₅₀, the effective concentration for causing 50% inhibition of mycelial growth inhibition of <i>P. melonis</i>.</p>d<p>Resistance factor  =  EC₅₀ of resistant isolates at the 10^th transfer/EC₅₀ of its parent.</p

Genetic relationships among 15 isolates of <i>Phytophthora melonis</i>.

<p>The denrogram (UPGMA) shows the relationships among the isolates of <i>P. melonis</i> based on randomly amplified polymorphic DNA (RAPD) analysis with 16 decamer primers. Scale at the bottom depicts the genetic distance.</p

Specificity of four allele-specific PCR primer pairs for the detection of carboxylic acid amide (CAA)-resistant isolates of <i>Phytophthora melonis</i>.

<p>(A) Specificity of the four primer pairs for the CAA-sensitive isolate TJ-58 (S) and the CAA-resistant isolate F58-4 (R) at gradient annealing temperatures. (B) Specificity of primer pair (PMF + PMR1109B) for four CAA-sensitive and five CAA-resistant isolates at 68.5°C.</p

Predicted amino acid sequence identities (%) among known CesA3s from four <i>Phytophthora</i> species, <i>Plasmopara viticola</i>, and <i>Arabidopsis thaliana.</i>

<p>Values indicate identity expressed as a percentage.</p

Nucleotide sequences and characteristics of primers used in this study.

<p>Nucleotide sequences and characteristics of primers used in this study.</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