Verticillium Wilt of Strawberry

In California, strawberry production begins with establishment of disease-free mother plants and the subsequent propagation of genetically identical daughter plants. After several cycles of nursery production, daughter plants are transplanted into fruit production fields, most of which are located in coastal growing districts. California has long been the nation's leader in the production of high quality fresh strawberries. In part, this has been achieved through the use of preplant fumigation, which helps to control problems caused by weeds and soilborne pathogens. However, methyl bromide, an essential ingredient in the most commonly used fumigation mixture will soon be unavailable to strawberry growers. As a result, it may no longer be possible to obtain consistent control of soilborne diseases such as Verticillium wilt, caused by Verticillium dahliae.

For this reason we are working with U.C. strawberry breeders to select for resistance to Verticillium wilt in high yielding varieties. Studies have shown that strawberry genotypes differ in their resistance to infection under nursery conditions, largely due to differences in the facility with which mother plants transmit the pathogen to daughter plants via their runners. In addition, genotypes differ in their ability to limit the development of infections in daughter plants. Thus, daughter plants may be infected when transplanted into a fruit production field, but never develop symptoms of the disease. It appears, therefore, that two different mechanisms of resistance to Verticillium wilt are operative in strawberries.

Selected Publications

Differential Infection of Mother and Runner Plant Generations by Verticillium dahliae in a High Elevation Strawberry (Fragaria x ananassa Duch.) Nursery. Gordon, T.R., Kirkpatrick, S.C., Shaw, D.V., and Larson, K.D. 2002.  HortScience 37:927-931.

Runner Plant Cold Storage Reduces Verticillium dahliae Infection of Nursery Origin in Strawberry. Shaw, D.V., Gordon, T.R., and Larson, K.D. 2002.  HortScience 37:932-935.