The crown gall is a plant disease caused by bacteria belonging to the genus Agrobacterium. It is presently the main bacterial disease of crops produced in nurseries in Mediterranean countries. The long term objective of the project is to decrease the prevalence of crown gall in nurseries to below a reasonable threshold providing substantial incomes to growers. This objective will be achieved by the development of new sanitary practices based on epidemiology, biocontrol and genetic control. As a specific objective, the scientists plan to establish a common set of standardized procedures to detect, identify and monitor the fate of the causative agent and to critically view the methods that could be used to control crown gall disease.
The work carried out in this project should provide :
1. The most important collection of Agrobacterium isolated in standardised conditions in six countries around the Mediterranean Sea; this will furnish useful data about the epidemiology of Agrobacterium as well as strains belonging to new types of agrobacteria and pTi.
2. Tools for phytosanitary inspection procedures to lower pathogenic populations will be evaluated and delivered.
3. Extended and integrated use of efficient biocontrol agents on major crops as well as resistance assessment of commercially important material.
The key activities envisaged are :
* Isolation, identification, detection and quantification of numerous pathogenic agrobacteria in various crops to study the origin and fate of agrobacterial populations within and between different crops and countries.
* Accurate characterisation of bacterial strains by PCR, RFLP, AFLP, sequencing and DNA hybridization will be conducted at both chromosomal and pTi levels by using ribosomal and vir and T-DNA regions respectively. This should lead to the discovery of new agrobacteria and pTi encoding for the biosynthesis of new opine compounds. Persistence of agrobacteria in plants and soil, including study of the stability and dispersion of the pTi, will be experimentally evaluated.
* Evaluation of procedures (sanitary practices, solarisation, heat treatments, etc.) to lower pathogenic populations in plant and soil reservoirs.
* Development of biological, genetical and physiological controls, including : testing efficiency of available biocontrol agents (K84), method to screen biocontrol efficiency in plant, and screening of new biocontrol agents; searching for intrinsic resistance among cultivars; and evaluating the control efficiency of compounds extracted from weeds.
Funding SchemeCSC - Cost-sharing contracts
46113 Moncada (Valencia)
1082 Tunis Mahrajene
80055 Portici Napoli