Forecasting infections of the red rot disease on Porphyra yezoensis Ueda (Rhodophyta) cultivation farms

Abstract

Pythium porphyrae is a fungal pathogen responsible for red rot disease of the seaweed Porphyra (Rhodophyta). Infection forecasts of Porphyra by P. porphyrae were estimated from the epidemiological observations of Porphyra thalli and numbers of zoospore of P. porphyrae in laboratory and cultivation areas. Four features of forecasting infections were determined by relating zoospore concentrations to the incidence of thallus infection; infection (in more than 1000 zoospores L −1 ), microscopic infection [less than 2 mm in diameter of lesion (in from 2000 to 3000 zoospores L −1 )], macroscopic infection [more than 2 mm in diameter of lesion (in from 3000 to 4000 zoospores L −1 ), and thallus disintegration (in more than 4000 zoospores L −1 ). High zoospore concentrations led to more infection. The tendency that zoospore concentration of P. porphyrae increased with the rate of infection of Porphyra thalli was generally observed in forecasting infections in both the laboratory and in cultivation areas. Based on the Porphyra cultivation areas, the accuracy and consistency of forecasting infections suggest that this method could be employed to manage and control red rot disease.

Chemical interactions between marine macroalgae and bacteria

“…and the white rot in Nereocystis spp. (Lavilla-Pitogo 1992, Correa et al 1993, Park et al 2006, and references therein). Red rot disease is caused by the fungal pathogen Phytium porphyrae affecting different Porphyra species, one of the most popular edible and extensively cultivated macroalga, especially in Asia.…”

“…The growing use of macroalgae and their products enforces the need to understand the nature and severity of diseases that can be anticipated in macroalgal mariculture (Apt 1984). The development of appropriate strategies will provide adequate and improved protection of the macroalgae in order to lower commercial risks (Park et al 2006). For this purpose, pathogens of macroalgae have to be identified and characterized at the species level and strategies have to be developed to prevent infection of macroalgae by such pathogens.…”

The responses of brown macroalgae to environmental change from local to global scales: direct versus ecologically mediated effects

“…Diseases are a frequent problem in seaweed aquaculture (reviewed by Gachon et al 2010), where bacterial (e.g. Craigie & Correa 1996, Largo et al 1999, Park et al 2006, algal (e.g. Bolton et al 2009), fungal (e.g.…”

A revaluation of algal diseases in Korean Pyropia (Porphyra) sea farms and their economic impact

“…It is our understanding that there is no P. marinum parasite on Pyropia. In Korea, redrot disease was shown to be caused only by P. porphyrae (Park et al 2001a(Park et al , 2001c(Park et al , 2006.…”