Mushrooms: Identification, detection and control of Pseudomonas species causing different types of bacterial blotch symptoms


SummaryThe proposed project aims to provide tools that will assist evaluation and development of potential control methods for bacterial blotch disease (caused by differentPseudomonas species), which is considered to be the most important disease problem currently faced by the mushroom industry in the UK and elsewhere in Europe

Project code:
M 063
01 May 2017 - 30 April 2018
AHDB Horticulture
AHDB sector cost:
Project leader:


M 063 Final Report

About this project

1. Ensure that the full diversity of Pseudomonas species currently causing significant losses to the UK mushroom industry is known and can be detected early in the supply chain and production processes so as to avoid potential losses and maximise yield of high quality mushrooms.
2. To develop and evaluate potential control measures which could have practical application in commercial mushroom production, and to demonstrate their efficacy against the known diversity of blotch-causing Pseudomonas species.
1. Review the phylogenetic and ecological relationships between the various fluorescent Pseudomonas species causing bacterial blotch disease and those which are beneficial for mushroom production and may contribute to disease suppression.  
2. Compare blotch pathogenicity obtained from small-scale culture test and cap tissue bioassay.
3. Generate whole genome sequences of blotch-causing isolates of P. tolaasii, P. gingeri and other Pseudomonas sp. and perform bioinformatic analysis to compare these with other sequenced isolates. 
4. Select DNA sequences that (i) are unique to pathogenic isolates and not found in non-pathogenic Pseudomonas species (ii) distinguish isolates causing typical bacterial blotch, ginger blotch or mild blotch symptoms.  
5. Develop improved diagnostic tests (e.g. real-time PCR or LAMP assays) which detect and differentiate Pseudomonas species pathogenic to mushrooms in both casing and mushroom samples, and evaluate performance of new tests using reference isolates, casing and Phase III compost samples and symptomatic mushrooms from commercial sources.
6. Investigate control of different types of bacterial blotch by manipulation of the casing bacterial population through use of casing additives and casing inoculum and addition of calcium chloride to irrigation water