Advertisement

Oecologia

, Volume 90, Issue 4, pp 509–517 | Cite as

Epidemiology of anther-smut disease (Microbotryum violaceum) and numeric regulation of populations ofSilene dioica

  • Ulla Carlsson
  • Thomas Elmqvist
Original Papers

Summary

The interaction between the anther smutMicrobotryum violaceum and its hostSilene dioica was studied during 1985–1990 in 47 populations of different ages, sizes and densities, in an archipelago area in northern Sweden. The sizes of these populations had also been surveyed in the early 1970s. Our results indicate that establishment ofMicrobotryum violaceum is host-size and density dependent. Firstly, young populations ofSilene dioica that became diseased during the study were larger and tended to be more dense than young populations that remained healthy. Secondly, populations diseased in both 1985 and 1990 were found to be larger and tended to be more dense than populations healthy in both years. We were able to document that the pathogen actually failed to establish in two small young populations (diseased plants died shortly after they appeared) and did go extinct in one small old population. Disease incidences within populations did not show large fluctuations between years. The highest increases in disease incidence during the study were found in three relatively young populations that were disease-free at the start of the study. Older populations highly diseased at the start showed less of an increase. Our study indicates thatMicrobotryum violaceum acts as a regulatory factor influencing the rate of increase inSilene dioica populations, once they are sufficiently large to maintain the pathogen. Firstly, seedling density decreased with increased incidence of disease and a seed addition experiment indicated seed-limited recuritment in highly diseased populations. Secondly, those populations that reached very large sizes or densities were either healthy or had very low incidences, indicating the potential for populations that for one reason or another escape an epidemic. However, in the comparison of changes in population size over 16–18 years there was no simple correlation between expansion rate and disease incidence.

Key words

Host/pathogen interaction Disease establishment Host population regulation Silene dioica Microbotryum violaceum (syn.Ustilago violacea

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Ågren J, Elmqvist T, Tunlid A (1986) Pollination by deceit, floral sex ratios and seed set in dioeciousRubus chamaemorus. Oecologia 70: 332–338Google Scholar
  2. Alexander HM (1987) Pollination limitation ofSilene alba infected by the anther-smut fungi,Ustilago violacea. J Ecol 75: 771–780Google Scholar
  3. Alexander HM (1989) An experimental field study of anther-smut disease ofSilene alba caused byUstilago violacea: genotypic variation and disease incidence. Evolution 43: 835–847Google Scholar
  4. Alexander HM (1990a) Dynamics of plant-pathogen interaction in natural plant communities. In: Burdon JJ, Leather SR (eds) Pests, pathogens and plant communities. Blackwell Scientific Publications, Oxford, pp 31–45Google Scholar
  5. Alexander HM (1990b) Epidemiology of anther-smut infection ofSilene alba caused byUstilago violacea: patterns of spore deposition and disease incidence. J Ecol 78: 166–179Google Scholar
  6. Alexander HM, Antonovics J (1988) Disease spread and population dynamics of anther smut infection ofSilene alba caused by the fungusUstilago violacea. J Ecol 76: 91–104Google Scholar
  7. Alexander HM, Maltby A (1990) Anther-smut infection of Silenealba caused byUstilago violacea: factors determining fungal reproduction. Oecologia 84: 249–253Google Scholar
  8. Antonovics J, Levin DA (1980) The ecological and genetic consequences of density/dependent regulation in plants. Annu Rev Ecol Syst 11: 411–452Google Scholar
  9. Anderson RM, May RM (1986) The invasion persistence and spread of infectious diseases within animal and plant communities. Philos Trans R Soc London 533–570 Series B 314Google Scholar
  10. Augspurger CK (1989) Impact of pathogens on natural plant populations. In: Davy AJ, Hutchings MJ, Watkinson AR (eds) Plant Population Ecology. Blackwell Scientific Publications, Oxford, pp 413–433Google Scholar
  11. Baker HG (1947) Biological flora of the British IslesMelandrium (Roehling em) FriesM album (Mill) Garcke and Mdiocium (Lemend) Coss and Germ. J Ecol 35: 271–292Google Scholar
  12. Bradshaw AD (1959) Population differentiation inAgrostis tenuis Sibth. II: The incidence and significance of infection byEpichloe typhina. New Phytol 58: 10–315Google Scholar
  13. Burdon JJ (1987) Diseases and plant population biology. Cambridge University Press, Cambridge, UKGoogle Scholar
  14. Burdon JJ, Chilvers JA (1982) Host density as a factor in plant disease ecology. Annu Rev Phytopathol 20: 143–166Google Scholar
  15. Carlsson U, Elmqvist T, Wennström A, Ericson L (1990) Infection by pathogens and population age of host plants. J Ecol 78: 1094–1105Google Scholar
  16. Clay K (1988) Fungal endophytes in stems and leaves: from latent pathogen to mutualistic symbiont. Ecology 69: 2–9Google Scholar
  17. Clay K (1990) Insects endophytic fungi and plants. In: Burdon JJ, Leather SR (eds) Pests, pathogens and plant communities. Blackwell Scientific Publications. Oxford, pp 111–130Google Scholar
  18. Elmqvist T, Gardfjell H (1988) Differences in response to defoliation between males and females ofSilene dioica. Oecologia 77: 225–230Google Scholar
  19. Ericson L, Wallentinus H-G (1979) Sea-shore vegetation around the Gulf of Bothnia. Wahlenbergia 5, pp 4–142Google Scholar
  20. Getz WM, Pickering J (1983) Epidemic models: thresholds and population regulation. Am Nat 121: 892–898Google Scholar
  21. Handel SN (1983) Pollination biology plant population structure and gene flow. In: L Real (ed) Pollination biology. Academic Press, London England, pp 163–211Google Scholar
  22. Harper JL (1990) Pests pathogens and plant communities: an introduction. In: Burdon JJ, Leather SR (eds) Pests pathogens and plant communities. Blackwell Scientific Publications, Oxford, pp 3–14Google Scholar
  23. Hassan A, MacDonald JA (1971)Ustilago violacea onSilene dioica. Trans Br Mycol Soc 56: 451–461Google Scholar
  24. Jennersten O (1985) Pollination and fungal disease transmission: interactions betweenViscaria vulgaris, Ustilago and insects. Acta Univ Ups 793: 1–33Google Scholar
  25. Jennersten O (1988a) Insect dispersal of fungal disease: effects ofUstilago infection on pollinator attraction inViscaria vulgaris. Oikos 51: 163–170Google Scholar
  26. Jennersten O (1988b) Pollination inDianthus deltoides (Caryophyllaceae) Effects of habitat fragmentation on visitation and seed set. Conserv Biol 2: 359–366Google Scholar
  27. Jennersten O, Nilsson SG, Wästljung U (1983) Local plant populations as ecological islands: the infection ofViscaria vulgaris by the fungusUstilago violacea. Oikos 41: 391–395Google Scholar
  28. Lee JA (1981) Variation in the infection ofSilene dioica byUstilago violacea in north west England. New Phytol 87: 81–89Google Scholar
  29. MacArthur RH, Wilson EO (1967) The theory of island biogeography. Princton University Press, Princton, New YerseyGoogle Scholar
  30. May RM (1990) Population biology and population genetics of plant-pathogen associations. In: Burdon JJ, Leather SR (eds) Pests, pathogens and plant communities. Blackwell Scientific Publications, Oxford, pp 309–325Google Scholar
  31. Schaffer WM, Scaffer MV (1977) The adaptive significance of variation in reproductive habitat in Agavacea In: Stonehouse B, Perrins C (eds) Evolutionary biology, Macmillan, London, pp 261–276Google Scholar
  32. Stephenson AG, Bertin RI (1983) Sexual selection in plants In: Real L (ed) Pollination biology. Academic Press, Orlando Fl USA, pp 109–149Google Scholar
  33. Wennström A, Ericson L (1990) Variation in diseased incidence in grazed and ungrazed sites for the systemPulsatilla pratensis —Puccinia pulsatilae. Oikos 60: 35–39Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • Ulla Carlsson
    • 1
  • Thomas Elmqvist
    • 1
  1. 1.Department of Ecological BotanyUniversity of UmeåUmeåSweden

Personalised recommendations