ARS | Publication request: Marker Stability throughout 400 Days of Hyphal Growth of Sclerotinia sclerotiorum

Submitted to: Fungal Genetics and Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 27, 2007
Publication Date: February 1, 2008
Citation: Kohn, L., Anderson, J.B., Schaffer, M.R., Grunwald, N.J. 2008. Marker stability throughout 400 Days of hyphal growth of Sclerotinia sclerotiorum. Fungal Genetics and Biology. 45:613-617.

Interpretive Summary: Sclerotinia sclerotiorum is a plant pathogenic fungus affecting many agronomic crops. In this study, we evaluated whether cultures of this pathogen maintained in the lab mutate in any detectable way. Two replicates of twelve laboratory strains of Sclerotinia sclerotiorum were propagated serially in race tubes for up to 400 days in the dark at room temperature (22°C). Five of these isolates were also propagated at 30°C with two replicates. No mutations were observed in four different methods of monitoring mutation in which molecular and microbiological tools were used. These same tools generally show variation in isolates obtained from infected field crops. This study demonstrated that in S. sclerotiorum these molecular tools are stable over time in laboratory isolates.

Technical Abstract: Two replicates of twelve laboratory strains of Sclerotinia sclerotiorum, including the genome isolate, were propagated serially in race tubes for up to 400 days in the dark at room temperature (22°C). Five of these isolates were also propagated at 30°C with two replicates. In sampling at intervals during culture, no mutations were observed in mycelial compatibility groupings (MCGs), DNA fingerprints, alleles at 7 microsatellite loci, or alleles at 56 AFLP loci. All of these markers show variation in field populations which are likely to be much larger and influenced by different and more stochastic evolutionary processes than laboratory isolates. This study demonstrated that in S. sclerotiorum, population genetic markers are stable over time in laboratory isolates.