Infection Of Select Pinaceae And Cupressaceae Seedlings To Phytophthora Pinifolia

Phytophthora pinifolia caused a devastating disease on Monterey pine (Pinus radiata) in Chile. This pathogen has not been reported in the United States, but there is concern should it arrive. There is little information regarding other hosts besides Monterey pine that may be susceptible to this pathogen. In the present study, other potential hosts within the Pinaceae and Cupressaceae were inoculated with zoospores of P. pinifolia and observed for symptoms and infection after 4 weeks. Similar to Monterey pine, knobcone (Pinus attenuata), bishop (P. muricata), and ponderosa (P. ponderosa) pines were highly infectious, whereas several important species such as loblolly pine (P. taeda) and Douglas fir (Pseudotsuga menziesii) showed no infection. P. pinifolia was also not recovered from slash (Pinus elliottii) and eastern white (P. strobus) pines. This study is important because it demonstrates other economically important tree hosts are at risk by P. pinifolia, should it enter the United States.