1a.Objectives (from AD-416):
With the use of alternative fumigants as replacements for methyl bromide as well as alternative fumigation practices there has been an increase in the incidence of plant death caused by M. phaseolina. The objective of this project is to evaluate the population structure of the pathogen recovered from strawberry and other hosts to see what level of variation is present and if there is any host specific association of genotypes.
1b.Approach (from AD-416):
Isolates of M. phaseolina will be collected from strawberry and other hosts growing in the different strawberry production districts in the state and evaluated for virulence on strawberry and several other host plants. Cultures will also be made available to the USDA, Agricultural Research Service (ARS) for genotyping.
This agreement was established in support of objective 2 of the parent project, the goal being to develop molecular diagnostic tools for the identification of emerging diseases of vegetables and strawberry, and use these tools in the development of management strategies as alternatives to methyl bromide. Accomplishments this year include collection of additional isolates of the pathogen from around California, work to improve the ability to recover the pathogen when plating soil, and pathogenicity tests with strawberry isolates on a range of hosts. Preliminary pathogenicity tests confirmed the virulence of strawberry isolates on strawberry, but these isolates were not able to infect other hosts commonly infected by Macrophomina phaseolina.