Movement ofPhytophthoraspp. in Maryland's Nursery Trade

Abstract

Phytophthora spp. cause major losses in the nursery industry worldwide. However, a clear demonstration of the route of movement has not been previously shown. A survey of 10 Maryland nurseries was conducted over a 3-year period to investigate the presence of Phytophthora spp. on newly arrived plants, mainly from West Coast suppliers. Local nursery plants, irrigation water, and potting media were also sampled for Phytophthora spp. Isolates were identified using a combination of morphological characteristics and DNA sequencing. Species identified included Phytophthora cactorum, P. cambivora, P. cinnamomi, P. citrophthora, P. drechsleri, P. elongata, P. gonapodyides, P. hydropathica, P. irrigata, P. lacustris, P. multivora, P. nicotianae, P. pini, P. plurivora, and P. syringae. P. taxon pgchlamydo was also isolated from irrigation water. Eight of the abovementioned Phytophthora spp. were isolated in association with incoming material, indicating that the movement of these pathogens continues to occur. Asymptomatic plant material was the main route of introduction of Phytophthora spp. to Maryland nurseries. Results also indicated that several Phytophthora spp. could be found in Maryland nurseries in association with infested potting media of asymptomatic plants. Although P. ramorum was not detected, our surveys underscore the significance of nursery practices that allow introductions of these significant plant pathogens to new geographic locations.

Phytophthora hydropathica y Phytophthora drechsleri aisladas de canales de irrigación del Valle de Culiacán

“…Phytophthora species require aquatic environments in order to develop their asexual life cycle and therefore spread quickly with the formation of sporangia and zoospores; for this reason, they have been regularly isolated from irrigation water channels, water reservoirs, and rivers (Sutton et al, 2009;Ghimire et al,2009;Hulvey et al, 2010;Bienapfl and Balci et al, 2014). Examples of species reported with this dispersal mean include P. cactorum, P. parasitica, P. citricola, P. gonapodyides, and P. cambivora, isolated from irrigation waters in the state of Washington (Yamak et al, 2002).…”

“…Revista Mexicana de FITOPATOLOGÍA Mexican Journal of Phytopathology asexual y así dispersarse rápidamente mediante la formación de esporangios y zoosporas; por ello han sido aisladas con regularidad de canales de agua de irrigación, reservorios de agua y ríos (Sutton et al, 2009;Ghimire et al, 2009;Hulvey et al, 2010;Bienapfl y Balci et al, 2014). Algunos ejemplos de especies reportadas con este medio de diseminación son: P. cactorum, P. parasitica, P. citricola, P. gonapodyides y P. cambivora, aisladas de aguas de irrigación en el estado de Washington (Yamak et al, 2002).…”

“…The dishes were kept at room temperature (25±2 °C) for 24-48 h (Gallegly and Hong, 2008;Bienapfl and Balci, 2014). The sporangia were observed under a Carl Zeiss Axiostar Imager A2 light microscope with an integrated camera and measured using the software ZEN 2012 Blue edition (Carl Zeiss).…”

“…Se indujo la producción de esporangios tomando secciones de aproximadamente 10 mm 2 de coStructures such as hyphal swellings, antheridia, oogonia and oospores were observed in clarified V8 agar medium(V8 juice under 4000 rpm for 20 min) in cultures of approximately one month of age, incubated in the dark at 20 °C (Mitchell et al, 1992;Bienapfl and Balci, 2014). To determine the maximum growth temperature, discs of 5 mm in diameter with active growth were placed in V8 medium and incubated at 30, 35, and 40 °C ± 1 °C.…”

“…Las placas se mantuvieron a temperatura ambiente (25±2 °C) durante 24-48 h (Gallegly y Hong, 2008;Bienapfl y Balci, 2014). Los esporangios se observaron en un microscopio óptico marca Carl Zeiss Axiostar Imager A2 con cámara integrada y se midieron con el software ZEN 2012 Blue edition (Carl Zeiss).…”