Sunflower (Helianthus annuus) is host to infections by Sclerotinia sclerotiorum originating from either homothallic sexually-derived ascospores (stem and head rots) or asexually-derived sclerotia (root rot). While sunflower can be infected by either ascospores or sclerotia this study found no association between the genotypes found in lesions and the type of infection (stem, head or root rot). Multicopy Restriction Fragment Length Polymorphisms (RFLPs) showed individual sclerotia comprised of only one genotype, and that all eight ascospores within an ascus also had only one genotype. Mycelial Compatibility Groups (MCGs), Random Amplified Polymorphic DNAs (RAPDs), single and multicopy RFLP analyses all showed the majority of sunflower plants were infected by only one genotype. A sample of 250 isolates collected hierarchically from sunflowers in Queensland and New South Wales were shown to belong to one large genetic population of S. sclerotiorum. Temporal studies revealed genetic uniformity was maintained across years, further confirming one genetic population. A range of molecular markers were used to genotype 120 isolates, resulting in differing levels of resolution of a genotype. Between 13 and 24 genotypes were identified with similarities and differences in the assemblages of isolates within each genotype depending on the marker used.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
Tax calculation will be finalised during checkout.
Atallah ZK, Larget B, Chen X, Johnson DA (2004) High genetic diversity, phenotypic uniformity, and evidence of outcrossing in Sclerotinia sclerotiorum in the Columbia basin of Washington State. Phytopathology 94:737–742
Boland GJ, Hall R (1994) Index of plant hosts of Sclerotinia sclerotiorum. Can J Plant Pathol 16:93–108
Carbone I, Anderson JB, Kohn LK (1999) Patterns of descent in clonal lineages and their multilocus fingerprints are resolved with combined gene genealogies. Evolution 53:11–21
Carlier J, Lebrun MH, Zapater MF, Dubois C, Mourichon X (1996) Genetic structure of the global population of banana black leaf streak fungus, Mycosphaerella fijiensis. Mol Ecol 5:499–510
Chen RS, McDonald BA (1996) Sexual reproduction plays a major role in the genetic structure of populations of the fungus Mycosphaerella graminicola. Genetics 142:1119–1127
Chen RS, Boeger JM, McDonald BA (1994) Genetic stability in a population of plant pathogenic fungus over time. Mol Ecol 3:209–218
Clarke RG (1982) Evaluation of the reaction of sunflower cultivators to Sclerotinia stem rot (Sclerotinia minor), and time of infection on yield. Department of Agricultural Research 142:1–12
Colotelo N (1973) A scanning electron microscope study of developing sclerotia of Sclerotinia sclerotiorum. Can J Bot 52:1127–1130
Durman SB, Menendez AB, Godeas AM (2003) Mycelial compatibility groups in Buenos Aires field populations of Sclerotinia sclerotiorum (Sclerotiniaceae). Aust J Bot 51:421–427
Ekins MG (1993) Genetic Diversity in Sclerotinia spp. Identified Through Molecular Markers and Host Range Studies. Honours Thesis. University of Queensland
Ekins MG, Aitken EAB, Goulter KC (2002) Carpogenic germination of Sclerotinia minor and potential distribution in Australia. Australas Plant Pathol 31:259–265
Ekins MG, Aitken EAB, Goulter KC (2005) Identification of Sclerotinia species. Australas Plant Pathol 34:1–7
Ekins MG, Aitken EAB, Goulter KC (2006) Homothallism in Sclerotinia minor. Mycol Res 110:1193–1199
Ekins MG, Aitken EAB, Goulter KC (2007) Aggressiveness among isolates of Sclerotinia sclerotiorum from sunflower. Australas Plant Pathol 36:580–586
Errampalli D, Kohn LM (1995) Comparison of pectic zymograms produced by different clones of Sclerotinia sclerotiorum in culture. Phytopathology 85:292–298
Farris J, Kallersjo M, Kluge A, Bult C (1995) Testing significance of incongruence. Cladistics 10:315–319
Ford EJ, Casquilho HE, Miller RV, Sands DC (1992) First report of heterokaryon in Sclerotinia sclerotiorum. Phytopathology 82:1082, Abstract
Ford EJ, Miller RV, Gray H, Sherwood JE (1995) Heterokaryon formation and vegetative compatibility in Sclerotinia sclerotiorum. Mycol Res 99:241–247
Grogan RG (1979) Sclerotinia species: summary and comments on needed research. Phytopathology 69:908–910
Hambleton S, Walker C, Kohn LM (2002) Clonal lineages of Sclerotinia sclerotiorum previously known from other crops predominate in 1999-2000 samples from Ontario and Quebec soybean. Can J Plant Pathol 24:309–315
Hutcheson K (1970) A test for comparing diversities based on the Shannon formula. J Theor Biol 29:151–154
Kohli Y, Kohn LM (1998) Random association among alleles in clonal populations of Sclerotinia sclerotiorum. Fungal Genet Biol 23:139–149
Kohli Y, Morrall RAA, Anderson JB, Kohn LM (1992) Local and Trans-Canadian clonal distribution of Sclerotinia sclerotiorum on canola. Phytopathology 82:875–880
Kohli Y, Brunner LJ, Yoell H, Milgroom MG, Anderson JB, Morrall RAA, Kohn LM (1995) Clonal dispersal and spatial mixing in populations of the plant pathogenic fungus, Sclerotinia sclerotiorum. Mol Ecol 4:69–77
Kohn LM, Carbone I, Anderson JB (1990) Mycelial interactions in Sclerotinia sclerotiorum. Exp Mycol 14:255–267
Kohn LM, Stasovski E, Carbone I, Royer J, Anderson JB (1991) Mycelial incompatibility and molecular markers identify genetic variability in field populations of Sclerotinia sclerotiorum. Phytopathology 81:480–485
Kull LS, Pedersen WL, Palmquist D, Hartman GL (2004) Mycelial compatibility grouping and aggressiveness of Sclerotinia sclerotiorum. Plant Dis 88:325–332
Maltby AD, Mihail JD (1994) Infection of canola by multiple genotypes of Sclerotinia sclerotiorum in central Missouri. Phytopathology 84:1101
Maltby AD, Mihail JD (1997) Competition among Sclerotinia sclerotiorum genotypes within canola stems. Can J Bot 75:462–468
Malvarez G, Carbone I, Grunwald NJ, Subbarao KV, Schafer MR, Kohn LM (2007) New populations of Sclerotinia sclerotiorum from lettuce in California and peas and lentils in Washington. Phytopathology 97:470–483
Marciano P, Di Lenna P, Magro P (1983) Oxalic acid, cell wall-degrading enzymes and pH in pathogenesis and their significance in the virulence of two Sclerotinia sclerotiorum isolates on sunflower. Physiol Plant Pathol 22:339–345
MIT BIoHa (2005) Sclerotinia sclerotiorum Sequencing Project. Broad Institute of Harvard and MIT.
Nei M (1972) Genetic distance between populations. Am Nat 106:283–292
Nei M (1973) Analysis of gene diversity in subdivided populations. Proc Natl Acad Sci USA 70:3321–3323
Phillips DV, Carbone I, Gold SE, Kohn LM (2002) Phylogeography and genotype-symptom associations in early and late season infections of canola by Sclerotinia sclerotiorum. Phytopathology 92:785–793
Pratt RG, Rowe DE (1995) Comparative pathogenicity of isolates of Sclerotinia trifoliorum and S. sclerotiorum on alfalfa cultivars. Plant Dis 79:474–477
Price K, Colhoun J (1975) A study of variability of isolates of Sclerotinia sclerotiorum (Lib.) de Bary from different hosts. J Phytopathol 83:159–166
Raymond M, Rousset F (1995a) An exact test for population differentiation. Evolution 49:1280–1283
Raymond M, Rousset F (1995b) GENEPOP (Version 1.2): population genetics software for exact tests and Ecumenicism. J Hered 86:248–249
Rice WR (1988) Analyzing tables of statistical tests. Evolution 43:223–225
Sedun FS, Brown JF (1989) Comparison of three methods to assess resistance in sunflower to basal stem rot caused by Sclerotinia sclerotiorum and S. minor. Plant Dis 73:52–55
Sexton AC, Howlett BJ (2004) Microsatellite markers reveal genetic differentiation among populations of Sclerotinia sclerotiorum from Australian canola fields. Curr Genet 46:357–365
Sexton AC, Whitten AR, Howlett BJ (2006) Population structure of Sclerotinia sclerotiorum in an Australian canola field at flowering and stem-infection stages of the disease cycle. Genome 49:1408–1415
Stoddart JA, Taylor JF (1988) Genotypic diversity: estimation and prediction in samples. Genetics 118:705–711
Swofford DL (2002) Phylogenetic Analysis Using Parsimony (and Other Methods). In: 4th edn. Sinauer Associates, Sunderland, Massachusetts
Uhm JY, Fujii H (1983) Heterothallism and mating type mutation in Sclerotinia trifoliorum. Phytopathology 73:569–572
Weir BS (1996) ‘Genetic Data Analysis II’. Sinauer Associates, Inc., Massachusetts
Williams GH, Western JH (1965) The biology of Sclerotinia trifoliorum Erikss., other species of sclerotium-forming fungi. II. The survival of sclerotia in soil. Ann Appl Biol 56:261–268
We gratefully acknowledge the financial support of the Grains Research and Development Corporation and Horticultural Research Development Corporation (now Horticulture Australia Ltd). We would like to thank Pacific Seeds Pty Ltd and Pioneer Seeds Hi-Bred Australia Pty Ltd for access to their sunflower breeding sites for sample collection. Merrick Ekins would like to thank Yatika Kohli, Ignazio Carbone and Tania Baker for their help and advice during his time at the University of Toronto. We would also like to thank Michelle Riedlinger and Sonya Clegg for help with the manuscript and Kathryn Hall for her help within PAUP parsimony and the congruence length difference test.
About this article
Cite this article
Ekins, M.G., Hayden, H.L., Aitken, E.A.B. et al. Population structure of Sclerotinia sclerotiorum on sunflower in Australia. Australasian Plant Pathol. 40, 99–108 (2011). https://doi.org/10.1007/s13313-010-0018-6
- Genetic diversity
- Population genetics
- Head rot
- Basal stem rot