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.
High magnification of single Chlamydospore showing further lack of ornamentation. Chlamydospores: Spherical structures with little or no surface ornamentation and averaging 42µm in diameter.
Chlamydospores; Note lack of surface ornamentation. Chlamydospores: Spherical structures with little or no surface ornamentation and averaging 42µm in diameter.
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.
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.
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.
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).
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.
Phytophthora ramorum sporulating on edge of bay leaf disk, 7 days after inoculation. Abundant sporangia and chlamydospores are present. Mature chlamydospores are amber-colored.
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