Microbial Ecology

, Volume 63, Issue 4, pp 711–718 | Cite as

Flowers as Islands: Spatial Distribution of Nectar-Inhabiting Microfungi among Plants of Mimulus aurantiacus, a Hummingbird-Pollinated Shrub

Notes and Short Communications

Abstract

Microfungi that inhabit floral nectar offer unique opportunities for the study of microbial distribution and the role that dispersal limitation may play in generating distribution patterns. Flowers are well-replicated habitat islands, among which the microbes disperse via pollinators. This metapopulation system allows for investigation of microbial distribution at multiple spatial scales. We examined the distribution of the yeast, Metschnikowia reukaufii, and other fungal species found in the floral nectar of the sticky monkey flower, Mimulus aurantiacus, a hummingbird-pollinated shrub, at a California site. We found that the frequency of nectar-inhabiting microfungi on a given host plant was not significantly correlated with light availability, nectar volume, or the percent cover of M. aurantiacus around the plant, but was significantly correlated with the location of the host plant and loosely correlated with the density of flowers on the plant. These results suggest that dispersal limitation caused by spatially nonrandom foraging by pollinators may be a primary factor driving the observed distribution pattern.

Notes

Acknowledgments

We thank Nona Chiariello and JRBP staff for assistance during field sampling, Chase Mendenhall for his contributions with hummingbird mist-netting, Trevor Hebert for assistance with Fig. S1, and the Biology 44Y students in the spring of 2011 for their assistance in collecting the data presented in Fig. S3. We also thank Bill Gomez, Nathan Kim, Christine Kyauk, Katrina Luna, Pat Seawell, Sebastian Calderon Bentin, and Diamantis Sellis for field and laboratory assistance; Annette Golonka and Carlos Herrera for technical advice; and Paul Ehrlich, Hal Mooney, Karen Nelson, members of the Fukami lab, and several anonymous reviewers for comments. Funding was provided by Stanford University.

Supplementary material

248_2011_9975_MOESM1_ESM.pdf (1.5 mb)
Figure S1 a Aerial photo and b map of the study area, showing topography, vegetation, and the location of sampled M. aurantiacus plant (PDF 1,524 kb)
248_2011_9975_MOESM2_ESM.ppt (478 kb)
Figure S2 Phylogenetic tree showing placement of taxa cultured from M. aurantiacus nectar at JRBP. The Saccharomycetales phylogeny was built using sequences primarily derived from an environmental study of nectar yeasts [8] and a recent phylogeny of the Saccharomycetales [40]. The species we found in this study are highlighted in red. Sequences were aligned using the program MAFFT [28], and phylogeny estimated using maximum likelihood with the program PhyML [21]. (PPT 477 kb)
248_2011_9975_MOESM3_ESM.pdf (28 kb)
Figure S3 Effect of caging M. aurantiacus plants (mesh size = 3 cm), which allowed insects, but not hummingbirds access, on microbial abundance in floral nectar, estimated by the total number of CFUs on YM plates. Bars and error bars show mean and 1 standard error, respectively. Sample size was n = 36 flowers for both treatments. Flower age at harvest was standardized to be 5 days. Caging affected microbial abundance significantly (t test, t = −2.12, p < 0.05; PDF 27 kb)

References

  1. 1.
    Anderson MC (1964) Studies of the woodland light climate: I. the photographic computation of light conditions. J Ecol 52:27–41CrossRefGoogle Scholar
  2. 2.
    Baas Becking LGM (1934) Geobiologie of inleiding tot de milieukunde. W.P. Van Stockum & Zoon, The HagueGoogle Scholar
  3. 3.
    Bahl J, Lau MCY, Smith GJD, Vijaykrishna D, Cary SC, Lacap DC, Lee CK, Papke RT, Warren-Rhodes KA, Wong FKY, McKay CP, Pointing SB (2011) Ancient origins determine global biogeography of hot and cold desert cyanobacteria. Nat Commun 2:163PubMedCrossRefGoogle Scholar
  4. 4.
    Baker HG, Baker I (1986) The occurrence and significance of amino acids in floral nectar. Plant Syst Evol 151:175–186CrossRefGoogle Scholar
  5. 5.
    Baker HG, Baker I (1987) The predictability of pollinator type by the chemistry of nectar. Am J Bot 74:645Google Scholar
  6. 6.
    Berkeley MJ (1863) The gardeners' chronicle & agricultural gazette, London, UK.Google Scholar
  7. 7.
    Boose DL (1997) Sources of variation in floral nectar production rate in Epilobium canum (Onagraceae): implications for natural selection. Oecologia 110:493–500CrossRefGoogle Scholar
  8. 8.
    Brody JR, Kern SE (2004) Sodium boric acid: a Tris-free, cooler conductive medium for DNA electrophoresis. Biotechniques 36:214–216PubMedGoogle Scholar
  9. 9.
    Brysch-Herzberg M (2004) Ecology of yeasts in plant–bumblebee mutualism in Central Europe. FEMS Microbiol Ecol 50:87–100PubMedCrossRefGoogle Scholar
  10. 10.
    Cain ML, Bowman WD, Hacker SD (2011) Ecology. Sinauer, SunderlandGoogle Scholar
  11. 11.
    Carter C, Healy R, O’Tool NM, Naqvi SMS, Ren G, Park S, Beattie GA, Horner HT, Thornburg RW (2007) Tobacco nectaries express a novel NADPH oxidase implicated in the defense of floral reproductive tissues against microorganisms. Plant Physiol 143:389–399PubMedCrossRefGoogle Scholar
  12. 12.
    Chazdon RL, Field CB (1987) Photographic estimation of photosynthetically active radiation: evaluation of a computerized technique. Oecologia 73:525–532CrossRefGoogle Scholar
  13. 13.
    Colwell RR (1994) Breeding territories of the male Anna’s hummingbirds at Jasper Ridge Biological Preserve. Biology 96 project, Jasper Ridge Paper, Stanford UniversityGoogle Scholar
  14. 14.
    de Vega C, Herrera CM, Johnson SD (2009) Yeasts in floral nectar of some South African plants: quantification and associations with pollinator type and sugar concentration. S Afr J Bot 75:798–806CrossRefGoogle Scholar
  15. 15.
    Fenchel T (2003) Biogeography for bacteria. Science 301:925–926PubMedCrossRefGoogle Scholar
  16. 16.
    Fetscher AE, Kohn JR (1999) Stigma behavior in Mimulus aurantiacus (Scrophulariaceae). Am J Bot 86:1130–1135PubMedCrossRefGoogle Scholar
  17. 17.
    Fetscher AE, Rupert SM, Kohn JR (2002) Hummingbird foraging position is altered by the touch-sensitive stigma of bush monkeyflower. Oecologia 133:551–558CrossRefGoogle Scholar
  18. 18.
    Fierer N, Jackson RB (2006) The diversity and biogeography of soil bacterial communities. Proc Natl Acad Sci USA 103:626–631PubMedCrossRefGoogle Scholar
  19. 19.
    Fierer N, Morse JL, Berthrong ST, Bernhardt ES, Jackson RB (2007) Environmental controls on the landscape-scale biogeography of stream bacterial communities. Ecology 88:2162–2173PubMedCrossRefGoogle Scholar
  20. 20.
    Finlay BJ (2002) Global dispersal of free-living microbial eukaryote species. Science 296:1061–1063PubMedCrossRefGoogle Scholar
  21. 21.
    Finlay BJ, Fenchel T (2004) Cosmopolitan metapopulations of free-living microbial eukaryotes. Protist 155:237–244PubMedCrossRefGoogle Scholar
  22. 22.
    Gill FB (1988) Trapline foraging by hermit hummingbirds: competition for an undefended, renewable resource. Ecology 69:1933–1942CrossRefGoogle Scholar
  23. 23.
    Golonka AM (2002) Nectar-inhabiting microorganisms (NIMs) and the dioecious plant species Silene latifolia.. PhD dissertation, Duke University, Durham, NCGoogle Scholar
  24. 24.
    Goslee SC, Urban DL (2007) The ecodist package for dissimilarity-based analysis of ecological data. J Stat Softw 22:1–19Google Scholar
  25. 25.
    Guindon S, Gascuel O (2003) A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood. Syst Biol 52:696–704PubMedCrossRefGoogle Scholar
  26. 26.
    Herrera CM, García IM, Pérez R (2008) Invisible floral larcenies: microbial communities degrade floral nectar of bumble bee-pollinated plants. Ecology 89:2369–2376PubMedCrossRefGoogle Scholar
  27. 27.
    Herrera CM, de Vega C, Canto A, Pozo MI (2009) Yeasts in floral nectar: a quantitative survey. Ann Bot 103:1415–1423PubMedCrossRefGoogle Scholar
  28. 28.
    Herrera CM, Canto A, Pozo MI, Bazaga P (2010) Inhospitable sweetness: nectar filtering of pollinator-borne inocula leads to impoverished, phylogenetically clustered yeast communities. Proc R Soc B 277:747–754PubMedCrossRefGoogle Scholar
  29. 29.
    Hosaka K, Castellano MA, Spatafora JW (2008) Biogeography of hysterangiales (Phallomycetidae, Basidiomycota). Mycol Res 112:448–462PubMedCrossRefGoogle Scholar
  30. 30.
    Janzen DH (1971) Euglossine bees as long-distance pollinators of tropical plants. Science 171:203–205PubMedCrossRefGoogle Scholar
  31. 31.
    Katoh K, Misawa K, Kuma K, Miyata T (2002) MAFFT: a novel method for rapid multiple sequence alignment based on fast Fourier transform. Nucleic Acids Res 30:3059–3066PubMedCrossRefGoogle Scholar
  32. 32.
    Kurtzman CP, Robnett CJ (1998) Identification and phylogeny of ascomycetous yeasts from analysis of nuclear large subunit (26S) ribosomal DNA partial sequences. Antonie Van Leeuwenhoek 73:331–371PubMedCrossRefGoogle Scholar
  33. 33.
    Lachance M, Starmer WT, Rosa CA, Bowles JM, Barker JSF, Janzen DH (2001) Biogeography of the yeasts of ephemeral flowers and their insects. FEMS Yeast Res 1:1–8PubMedGoogle Scholar
  34. 34.
    Lachance MA, Daniel HM, Meyer W, Prasad GS, Gautam SP, Boundy-Mills K (2003) The D1/D2 domain of the large-subunit rDNA of the yeast species Clavispora lusitaniae is unusually polymorphic. FEMS Yeast Res 4:253–258PubMedCrossRefGoogle Scholar
  35. 35.
    Lokvam J, Braddock JF (1999) Anti-bacterial function in the sexually dimorphic pollinator rewards of Clusia grandiflora (Clusiaceae). Oecologia 119:534–540CrossRefGoogle Scholar
  36. 36.
    Lumbsch HT, Buchanan PK, May TW, Mueller GM (2008) Phylogeography and biogeography of fungi. Mycol Res 112:423–424CrossRefGoogle Scholar
  37. 37.
    Mooney HA, Ehrlich PA, Lincoln DE, Williams KS (1980) Environmental controls on the seasonality of a drought deciduous shrub, Diplacus aurantiacus and its predator, the Checkerspot Butterfly, Euphydryas chalcedona. Oecologia 45:143–146CrossRefGoogle Scholar
  38. 38.
    O’Donnell K (1993) Fusarium and its near relatives. In: Reynolds DR, Taylor JW (eds) The fungal holomorph: mitotic, meiotic and pleomorphic speciation in fungal systematics. CAB International, Wallingford, pp 225–233Google Scholar
  39. 39.
    Oda Y, Star B, Huisman LA, Gottschal JC, Forney LJ (2003) Biogeography of the purple nonsulfur bacterium Rhodopseudomonas palustris. Appl Environ Microbiol 69:5186–5191PubMedCrossRefGoogle Scholar
  40. 40.
    Oksanen L, Kindt R, Legendre P, O’Hara B, Simpson GL, Solymos P, Henry M, Stevens H, Wagner H (2008) Vegan: Community Ecology Package. R package version 1.15-1. http://cran.r-project.org/, http://vegan.r-forge.r-project.org/
  41. 41.
    Peay KG, Bruns TD, Kennedy PG, Bergemann SE, Garbelotto M (2007) A strong species–area relationship for eukaryotic soil microbes: Island size matters for ectomycorrhizal fungi. Ecol Lett 10:470–480PubMedCrossRefGoogle Scholar
  42. 42.
    Peay KG, Belisle M, Fukami T (2011) Phylogenetic relatedness predicts priority effects in nectar yeast communities. Proc R Soc B. doi: 10.1098/rspb.2011.1230
  43. 43.
    Pozo MI, Herrera CM, Bazaga P (2011) Species richness of yeast communities in floral nectar of southern Spanish plants. Microb Ecol 61:82–91PubMedCrossRefGoogle Scholar
  44. 44.
    Stiles FG (1975) Ecology, flowering phenology, and hummingbird pollination of some Costa Rican Heliconia species. Ecology 56:285–301CrossRefGoogle Scholar
  45. 45.
    Streisfeld MA, Kohn JR (2007) Environment and pollinator-mediated selection on parapatric floral races of Mimulus aurantiacus. J Evol Biol 20:122–132PubMedCrossRefGoogle Scholar
  46. 46.
    Suh S, Blackwell M, Kurtzman CP, Lachance M (2006) Phylogenetics of Saccharomycetales, the ascomycete yeasts. Mycologia 98:1006–1017PubMedCrossRefGoogle Scholar
  47. 47.
    Telford RJ, Vandvik V, Birks HJB (2006) Dispersal limitations matter for microbial morphospecies. Science 312:1015PubMedCrossRefGoogle Scholar
  48. 48.
    Whitaker RJ, Grogan DW, Taylor JW (2003) Geographic barriers isolate endemic populations of hyperthermophilic archaea. Science 301:976–978PubMedCrossRefGoogle Scholar
  49. 49.
    Yarrow D (1998) Methods for the isolation, maintenance and identification of yeasts. In: Kurtzman CP, Fell JW (eds) The yeasts: a taxonomic study. Elsevier, Amsterdam, pp 77–100CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Melinda Belisle
    • 1
  • Kabir G. Peay
    • 1
    • 2
  • Tadashi Fukami
    • 1
  1. 1.Department of BiologyStanford UniversityStanfordUSA
  2. 2.Department of Plant PathologyUniversity of MinnesotaSt. PaulUSA

Personalised recommendations