Phytophthora foliorum sp. nov., a new species causing leaf blight of azalea.
A previously unknown Phytophthora was recovered more than 60 times from evergreen hybrid azalea leaves collected during surveys for the sudden oak death pathogen Phytophthora ramorum in California and Tennessee. The novel Phytophthora was discovered when genomic DNA from this species cross-reacted with the ITS-based diagnostic PCR primers used to screen plants for the presence of P. ramorum. This species had caducous, semi-papillate sporangia, was homothallic with both paragynous and amphigynous antheridia, and was pathogenic on both wounded and intact azalea leaves. Nuclear and mitochondrial sequence data indicate that this species is related to, but distinct from, P. ramorum. AFLP analysis indicates that the isolates of this species have limited genotypic diversity and share no markers with P. ramorum. This paper presents the formal description of P. foliorum as a new species and underscores the need for caution when relying solely on DNA-based diagnostic tools.
Donahoo
Ryan
R
Department of Entomology and Plant Pathology, The University of Tennessee, 2431 Joe Johnson Drive, Rm 205, Ellington Plant Science, Knoxville, TN 37996, USA.
Blomquist
Cheryl L
CL
Thomas
Samantha L
SL
Moulton
John K
JK
Cooke
David E L
DE
Lamour
Kurt Haas
KH
D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D005838:Genotype; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1 / Q000235:genetics; D010802:Phylogeny; D010838:Phytophthora / Q000145:classification / Q000235:genetics*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology*; D011110:Polymorphism, Genetic / Q000235:genetics; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D029793:Rhododendron / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D014404:Tubulin / Q000235:genetics
D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D020648:Peptide Elongation Factor 1; D012340:RNA, Ribosomal, 5.8S; D014404:Tubulin; D003576:Electron Transport Complex IV