Sudden Oak Death > Maps & Visual Media > Photos > P ramorum Micrographs
P ramorum Micrographs

Chlamydospores
Chlamydospores
Chlamydospores on and in bay leaf tissue (9 days after inoculation). Leaf tissue was cleared and stained to reveal chlamydospores, which appear blue in this photo.
Photo Credits |
Photomicrographs by Dr. Jennifer L. Parke,
Associate Professor (Research)
Department of Botany and Plant Pathology
& Department of Crop and Soil Science
Oregon State University, Corvallis, OR 97331 |

Sporangia
Sporangia
Sporangia (both discharged and non-discharged), and immature chlamydospores from a bay leaf 48 hours after inoculation.
Photo Credits |
Photomicrographs by Dr. Jennifer L. Parke,
Associate Professor (Research)
Department of Botany and Plant Pathology
& Department of Crop and Soil Science
Oregon State University, Corvallis, OR 97331 |

Sporangia & chlamydospores
Sporangia & chlamydospores
Close-up of sporangia (football-shaped structures) and chlamydospores (larger, round, amber-colored structures), 7 days after inoculation of bay leaf disks. Note that some of the sporangia are empty, having already released zoospores.
Photo Credits |
Photomicrographs by Dr. Jennifer L. Parke,
Associate Professor (Research)
Department of Botany and Plant Pathology
& Department of Crop and Soil Science
Oregon State University, Corvallis, OR 97331 |

Sporulation
Sporulation
Phytophthora ramorum sporulating on edge of bay leaf disk, 7 days after inoculation. Abundant sporangia and chlamydospores are present. Mature chlamydospores are amber-colored.
Photo Credits |
Photomicrographs by Dr. Jennifer L. Parke,
Associate Professor (Research)
Department of Botany and Plant Pathology
& Department of Crop and Soil Science
Oregon State University, Corvallis, OR 97331 |

Sporangia
Sporangia
Sporangia on a bay leaf disk, 24 hours after inoculation. Zoospores are being released from the sporangia (the swimming zoospores appear as streaks in this photo).
Photo Credits |
Photomicrographs by Dr. Jennifer L. Parke,
Associate Professor (Research)
Department of Botany and Plant Pathology
& Department of Crop and Soil Science
Oregon State University, Corvallis, OR 97331 |

Sporangia
Sporangia
Sporangia of Phytophthora ramorum on the edge of a bay leaf disk, 20 hours after inoculation.
Photo Credits |
Photomicrographs by Dr. Jennifer L. Parke,
Associate Professor (Research)
Department of Botany and Plant Pathology
& Department of Crop and Soil Science
Oregon State University, Corvallis, OR 97331 |

Chlamydospore
Chlamydospore
High magnification of single Chlamydospore showing further lack of ornamentation. Chlamydospores: Spherical structures with little or no surface ornamentation and averaging 42µm in diameter.
Photo Credits |
Edwin R. Florance Ph.D. |

Chlamydospore
Chlamydospore
Higher magnification of single chlamydospore to indicate further lack of surface ornamentation. Chlamydospores: Spherical structures with little or no surface ornamentation and averaging 42µm in diameter.
Photo Credits |
Edwin R. Florance Ph.D. |

Chlamydospores
Chlamydospores
Chlamydospore surrounded by hyphae. Chlamydospores: Spherical structures with little or no surface ornamentation and averaging 42µm in diameter.
Photo Credits |
Edwin R. Florance Ph.D. |

Chlamydospores
Chlamydospores
Chlamydospores; Note lack of surface ornamentation. Chlamydospores: Spherical structures with little or no surface ornamentation and averaging 42µm in diameter.
Photo Credits |
Edwin R. Florance Ph.D. |

Chlamydospores
Chlamydospores
Chlamydospores, varied magnifications. Chlamydospores: Spherical structures with little or no surface ornamentation and averaging 42µm in diameter.
Photo Credits |
Edwin R. Florance Ph.D. |

Cyst germination
Cyst germination
Cyst germination
Photo Credits |
Edwin R. Florance Ph.D. |

Hypahe in lenticels
Hypahe in lenticels
Hyphae growing in lenticels
Photo Credits |
Edwin R. Florance Ph.D. |

Hyphae
Hyphae
Hyphae - Note the nodular or nodose anatomy
Photo Credits |
Edwin R. Florance Ph.D. |

Hyphae in xylem
Hyphae in xylem
Hyphae in the Xylem of the same stem as previous
Photo Credits |
Edwin R. Florance Ph.D. |

Infected bay leaf
Infected bay leaf
Lower surface of infected California bay leaf, Umbellularia californica. Note chlamydospore, zoosporangia, and hyphae.
Photo Credits |
Edwin R. Florance Ph.D. |

Infected tanoak tissue
Infected tanoak tissue
Infected tissue in tanoak (Lithocarpus densiflorus). Note the nodulated hyphae of Phytophthora ramorum.
Photo Credits |
Edwin R. Florance Ph.D. |

Lenticel
Lenticel
Lenticel. Special structures in the periderm of the stem that allow for gas exchange. They are oval and average 37.67µm long by 20.2µm wide.
Photo Credits |
Edwin R. Florance Ph.D. |

P. ramorum cyst
P. ramorum cyst
P. ramorum cyst. Cysts of P. ramorum average 5.5µm in diameter, spherical, display an undulating surface, and depending on the stage of development the closing longitudinal groove is observed as a pore.
Photo Credits |
Edwin R. Florance Ph.D. |

P. ramorum cysts
P. ramorum cysts
P. ramorum cysts. Cysts of P. ramorum average 5.5µm in diameter, spherical, display an undulating surface, and depending on the stage of development the closing longitudinal groove is observed as a pore.
Photo Credits |
Edwin R. Florance Ph.D. |

Tanoak cortex
Tanoak cortex
Cortex in a 1 year old stem of tanoak (Lithocarpus densiflorus) infected with P. ramorum. Note: The thread like structures are the hyphae of P. ramorum
Photo Credits |
Edwin R. Florance Ph.D. |

Zoosporangia
Zoosporangia
Zoosporangia prior to zoospore release; note pedicel (arrow).
Photo Credits |
Edwin R. Florance Ph.D. |

Zoosporangia
Zoosporangia
Zoosporangia after release of zoospores. Note pedicel (arrow).
Photo Credits |
Edwin R. Florance Ph.D. |

Zoospore release
Zoospore release
Zoospore release
Photo Credits |
Edwin R. Florance Ph.D. |

Zoospores
Zoospores
Zoospores from pure culture. Note the biflagellation, reniform shape, longitudinal groove, and pitted surface.
Photo Credits |
Edwin R. Florance Ph.D. |

Zoospores
Zoospores
Zoospore from culture. Note the biflagellation, reniform shape, longitudinal groove, and pitted surface.
Photo Credits |
Edwin R. Florance Ph.D. |

Zoospores
Zoospores
Zoospores from culture. Note the biflagellation, reniform shape, longitudinal groove, and pitted surface.
Photo Credits |
Edwin R. Florance Ph.D. |