Phytophthora root rot of avocado, a soilborne disease caused by Phytophthora cinnamomi Rands, continues to be devastating to the cultivation of avocados despite more than 70 years of research on control methods. Phytophthora root rot has been estimated to be present in two-thirds of the avocado groves in California, causing losses of almost 30% of the total value of the crop (5). P. cinnamomi m...

Phytophthora cactorum is a broad host range phytopathogenic oomycete. P. cactorum strain LV007 was isolated from a diseased European Beech (Fagus sylvatica) in Malmö, Sweden in 2016. The draft genome of P. cactorum strain LV007 is 67.81 Mb. It contains 15,567 contigs and 21,876 predicted protein-coding genes. As reported for other phytopathogenic Phytophthora species, cytoplasmic effector prote...

Evolution algebra theory is used to study non-Mendelian inheritance, particularly organelle heredity and population genetics of Phytophthora infectans. We not only can explain a puzzling feature of establishment of homoplasmy from heteroplasmic cell population and the coexistence of mitochondrial triplasmy, but also can predict all mechanisms to form the homoplasmy of cell populations, which ar...

The first natural hybrids in the genus Phytophthora were described in 1998, and they were the result of hybridization between P. nicotianae and P. cactorum. They were described formally as Phytophthora × pelgrandis in 2009. In 2007 a second type of P. cactorum hybrid species was described, generated by hybridization between P. hedraiandra and P. cactorum; it is described formally here as P. × s...

Accelerated gene evolution is a hallmark of pathogen adaptation following a host jump. Here, we describe the biochemical basis of adaptation and specialization of a plant pathogen effector after its colonization of a new host. Orthologous protease inhibitor effectors from the Irish potato famine pathogen, Phytophthora infestans, and its sister species, Phytophthora mirabilis, which is responsib...

Treena I. Burgess, Centre for Phytophthora Science and Management, School of Biological Sciences and Biotechnology, Murdoch University, Murdoch, WA 6150, Australia; Janet L. Webster and Juanita A. Ciampini, Department of Environment and Conservation, Science Division, Locked Bag 104, Bentley D.C., WA 6983, Australia; Diane White and Giles E. StJ. Hardy, Centre for Phytophthora Science and Manag...

Oomycetes, such as Phytophthora spp., establish pathogenic interactions with a diversity of plants, but the molecular mechanisms underlying these diseases remain poorly characterized. However, research on Phytophthora pathosystems has accelerated significantly with ongoing advances in microbial and plant genomics and the resulting resources. A variety of functional analyses are being used to as...

Persistence of the avocado root-rot fungus Phytophthora cinnamami Rands in soil for 6 years without a living host was reported by Zentmyer and Mircetich (8). The authors suggested that the fungus may survive in dead avocado roots as inactive mycelia, chlamydospores or oospores. Blackwell (1) considers chlamydospores of Phytophthora spp. to be resistant structures which allow these fungi to pers...

Evolution algebra theory is used to study non-Mendelian inheritance, particularly organelle heredity and population genetics of Phytophthora infectans. We can not only explain a puzzling feature of establishment of homoplasmy from heteroplasmic cell population and the coexistence of mitochondrial triplasmy, but also predict all mechanisms to form the homoplasmy of cell populations, which are hy...