Table of Contents
What is the life cycle of Phytophthora?
Life cycle Sporangia release tiny, single-celled swimming spores called zoospores. Zoospores can swim through water on leaf surfaces or through water-logged soil, but they are susceptible to drying. Zoospores are attracted to plant roots as they swim through the soil, and when they find one, they form a cyst.
How do you stop Phytophthora ramorum?
Prevent diseased plants, like these infested with Phytophthora ramorum, from entering your nursery. Sanitize containers before re-use, or buy new ones. 140° F for one hour, are required to kill Phytophthora spp.
What does Phytophthora ramorum do?
Phytophthora ramorum is the oomycete (a type of Protist) plant pathogen known to cause the disease sudden oak death (SOD). The disease kills oak and other species of trees and has had devastating effects on the oak populations in California and Oregon, as well as being present in Europe.
How does Phytophthora enter the plant?
Under optimal conditions (moist and warm) Phytophthora produces zoospores in large numbers. Zoospores swim toward plant roots, as they are attracted to the chemicals that the roots release. Zoospores adhere to and infect the roots producing mycelium.
How do Phytophthora infestans reproduce?
The potato late blight pathogen Phytophthora infestans has both an asexual and a sexual mode of reproduction. In Scandinavia, the pathogen is reproducing sexually on a regular basis, whereas clonal lineages dominate in other geographical regions.
How does Phytophthora ramorum spread?
Phytophthora ramorum spores spread via wind-driven rain. When they land on a leaf they grow into the tree by breaking down the cell walls in the leaf. This leads to the initial blackening symptoms. It then grows within the tree and blocks its water transport system leading to dieback and eventual death.
What does Phytophthora ramorum eat?
Phytophthora ramorum kills tanoak (Lithocarpus densiflorus), black oak (Quercus kelloggii), canyon live oak (Quercus chrysolepis), coast live oak (Quercus agrifolia), Shreve oak (Quercus parvula var.
Where does Phytophthora come from?
Summary: Phytophthora cinnamomi Rands was first isolated from cinnamon trees in Sumatra in 1922. The pathogen is believed to have originated near Papua New Guinea but now has a worldwide distribution.
How does Phytophthora infestans spread?
P. infestans is thought to spread by mycelial growth within infected seed tubers, advancing contiguously or following growing shoots to produce spo- rangia capable of generating new infection foci (10,26,38).
How does Phytophthora infestans work?
The asexual life cycle of Phytophthora infestans is characterized by alternating phases of hyphal growth, sporulation, sporangia germination (either through zoospore release or direct germination, i.e. germ tube emergence from the sporangium), and the re-establishment of hyphal growth.
How do you get rid of Phytophthora in soil?
Steam heat is effective to kill Phytophthora in contaminated soil, media or on planting containers such as pots. If you re-use pots you can soak pre-cleaned pots in hot (180°F) water for at least 30 min or use aerated steam (140°F) for 30 min.