ARS | Publication request: Long Term Preservation of a Collection of Rhizoctonia Solani, using Cryogenic Storage

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 23, 2009
Publication Date: February 25, 2009
Citation: Hill, A.L., Webb, K.M., Lauffman, J., Hanson, M.K., Panella, L.W. 2009. Long Term Preservation of a Collection of Rhizoctonia Solani, using Cryogenic Storage. Meeting Abstract. Vol. 46 No. 1 & 2, Pages 88-89.

Technical Abstract: The fungus Rhizoctonia solani Kühn is an important plant pathogen on a number of crops and maintaining an extensive collection of reference isolates is important in understanding relationships of this pathogen with multiple hosts. While a number of long-term storage methods have been developed, most of these require frequent transfer, require the entire sample to be removed from storage, and can cause changes to morphological or pathogenic characteristics after several years. One hundred nine isolates of R. solani representing nine anastomosis groups were colonized onto barley grains which then were placed into individual cryotubes and stored at –160oC in liquid nitrogen vapor phase. At 60 days, 5, and 10 years, all isolates were removed from storage, placed on PDA plates and examined at 2 and 5 days after plating. Percentage of barley grains from which R. solani germinated and notations on morphological characteristics were recorded, and compared to data collected from the original cultures prior to storage. At each time period, a subset of isolates was inoculated to a susceptible (FC901) and a resistant (FC703) sugar beet cultivar. Roots were rated for symptoms on a scale of 0 (no visible symptoms) to 7 (plant dead and root completely rotted through). All isolates tested that were stored using the cryogenic method had no changes to either morphologic or pathogenic characteristics. This indicates that for permanent storage, cryogenic methods are well suited for the preservation of R. solani culture collections.