Scientists in Connecticut have accidentally discovered a new species of Phytophthora in Christmas trees. Also known as “the plant destroyer”, this genus of water mould causes substantial global crop loss, destroying natural ecosystems and economies.
Grown with the intention of being used as Christmas trees, Fraser firs are preferred by consumers due to their colour, scent and ability to hold their needles. However, the Fraser firs are highly susceptible to root rot disease making them a prime target for Phytophthora moulds.
While conducting experiments, testing various growing methods for Fraser trees, scientists in Connecticut accidentally discovered a new species of Phytophthora. By collecting diseased plants and isolating them, researchers were able to grow the pathogen on synthetic materials, researchers were able to inoculate it into healthy plants in order to prove its pathogenicity.
“Once the organism was isolated, the presence of unusually thick spore walls alerted us that this may not be a commonly encountered species,” said Rich Cowles, a scientist at the Connecticut Agricultural Experiment Station involved with this study.
Cowles continued: “and so comparison of several genes’ sequences with known Phytophthora species was used to discover how our unknown was related to other, previously described species.”With these scientists easily discovering this new species of Phytophthora infecting Christmas trees, it suggests that there are many more species waiting to be discovered.
It is important to understand the greater biodiversity of this mould effecting Christmas trees. The transportation of infected nursery stock and chance encounters of different Phytophthora species in the field could lead to new hybrids arising, possibly leading to new hybrids arising, which can have different pathogenic characteristics than their parent species.
“Knowing how many and which species are present is important, not only for Christmas tree growers, but also for protecting our natural environment…combining this robust old technique worked well with modern molecular biology methods to isolate, and then identify our unknown plant disease,”” Cowles adds.