Plant and Soil

, Volume 264, Issue 1–2, pp 335–348 | Cite as

Phosphorus and intraspecific density alter plant responses to arbuscular mycorrhizas

  • Michelle S. Schroeder
  • David P. Janos


We investigated how phosphorus availability, intraspecific density, and their interaction affect plant responses to arbuscular mycorrhizas. Four facultatively mycotrophic species: chile, cilantro, tomato, and corn were examined separately in pot experiments that employed a tropical phosphorus-immobilizing soil. Each experiment comprised nine soluble phosphorus additions, two levels of intraspecific plant density, and inoculation with arbuscular mycorrhizal fungi or not. High phosphorus signi- ficantly diminished mycorrhizal colonization of corn, cilantro, and tomato, but not chile, which was highly variably colonized. Corn roots were colonized by other root-inhabiting fungi, and mycorrhizas significantly reduced colonization by these potential root parasites. High phosphorus significantly increased relative growth rates (RGR) of all species, and high density significantly reduced RGR of cilantro, tomato, and corn. Chile showed little growth at any but the highest phosphorus additions, and consequently had no RGR response to density or mycorrhizas. Mycorrhiza inoculation caused transient depression of corn growth during the first month, but mycorrhizas increased corn RGR during the second month of growth. Both RGR and dry weights at harvest, cilantro, tomato, and corn benefited from mycorrhizas at low phosphorus availability, but this benefit diminished or changed to disadvantage as phosphorus availability increased. At low phosphorus availability, high density increased the dry weight of mycorrhizal cilantro and thereby amplified the benefit of mycorrhizas. At high phosphorus availability, increased density diminished the effects of mycorrhizas on dry weight, reducing mycorrhiza benefit to tomato and chile and reducing mycorrhiza detriment to cilantro. This study demonstrates that for three of the four plant species examined, phosphorus availability, intraspecific density, and their interaction significantly modify plant responses to arbuscular mycorrhizas.

arbuscular mycorrhizas growth depression intraspecific competition phosphorus availability relative growth rates 


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  1. Abbott L K, Robson A D and De Boer G 1984 The effect of phosphorus on the formation of hyphae in soil by the vesicular-arbuscular mycorrhizal fungus, Glomus fasciculatum. New Phytol. 97, 437–446.Google Scholar
  2. Allsopp N and Stock W D 1992 Density dependent interactions between VA mycorrhizal fungi and even-aged seedlings of two perennial Fabaceae species. Oecologia 91, 281–287.CrossRefGoogle Scholar
  3. Amijee F, Tinker P B and Stribley D P 1989 The development of endomycorrhizal root systems VII. A detailed study of effects of soil phosphorus on colonization. New Phytol. 111, 435–446.Google Scholar
  4. Azcón-Aguilar C and Barea J M 1996 Arbuscular mycorrhizas and biological control of soil-borne plant pathogens – an overview of the mechanisms involved. Mycorrhiza 6, 457–464.Google Scholar
  5. Chandrashekara C P, Patil V C and Sreenivasa M N 1995 VA-mycorrhiza mediated P effect on growth and yield of sunflower (Helianthus annuus L.) at different P levels. Plant Soil 176, 325–328.CrossRefGoogle Scholar
  6. Cooper K M1975 Growth responses to the formation of endotrophic mycorrhizas in Solanum, Leptopsermum and New Zealand ferns. In Endomycorrhizas. <nt>Eds.</nt> F E Sanders, B Mosse and P B Tinker. pp. 297–312. Academic Press, NY.Google Scholar
  7. Dehne H W 1982 Interaction between vesicular-arbuscular my-corrhizal fungi and plant pathogens. Phytopathology 72, 1115–1132.Google Scholar
  8. Eissenstat D M and Newman E I 1990 Seedling establishment near large plants: effects of vesicular-arbuscular mycorrhizas on the intensity of plant competition. Funct. Ecol. 4, 95–99.Google Scholar
  9. Facelli E, Facelli J M, Smith S E and McLaughlin M J 1999 Interactive effects of arbuscular mycorrhizal symbiosis, intraspecific competition and resource availability on Trifolium subterraneum cv. Mt. Barker. New Phytol. 141, 535–547.CrossRefGoogle Scholar
  10. Fitter A H 1991 Costs and benefits of mycorrhizas: Implications for functioning under natural conditions. Experientia 47, 350–355.CrossRefGoogle Scholar
  11. Giovannetti M and Mosse B 1980 An evaluation of techniques for measuring vesicular-arbuscular infection in roots. New Phytol. 84, 489–500.Google Scholar
  12. Hartnett D C, Hetrick A D, Wilson G W T and Gibson D J 1993 Mycorrhizal influence on intra-and interspecific neigh-bor interactions among co-occurring prairie grasses. J. Ecol. 81, 787–795.Google Scholar
  13. Hass J H, Bar-Tal A, Bar-Yosef B and Krikun J 1986 Nutrient availability effects on vesicular-arbuscular mycorrhizal bell pepper (Capsicum annuum) seedlings and transplants. Ann. Appl. Biol. 108, 171–179.Google Scholar
  14. Hayman D S 1983 The physiology of vesicular-arbuscular endomy-corrhizal symbiosis. Can. J. Bot. 61, 944–963.Google Scholar
  15. Hetrick B A D, Hartnett D C, Wilson G W T and Gibson D J 1994 Effects of mycorrhizae, phosphorous availability, and plant density on yield relationships among competing tallgrass prairie grasses. Can. J. Bot. 72, 168–176.Google Scholar
  16. Howeler R H and Sieverding E 1987 Practical aspects of mycor-rhizal technology in some tropical crops and pastures. Plant Soil 100, 249–283.Google Scholar
  17. Janos D P 1980 Mycorrhizae influence tropical succession. Biotropica 12, 56–64.Google Scholar
  18. Janos D P 1988 Mycorrhiza applications in tropical forestry: Are temporate-zone approaches appropriate? In Trees and Mycorrhiza. <nt>Ed.</nt> F S P Ng. pp. 133–188. Forest Research Institute, Malaysia, Kuala Lumpur.Google Scholar
  19. Jifon J L, Graham J H, Drouillard D L and Syversten J P 2002 Growth depression of mycorrhizal Citrus seedlings grown at high phosphorus supply is mitigated by elevated CO2. New Phytol. 153, 133–142.CrossRefGoogle Scholar
  20. Klironomos J N 2003 Variation in plant response to native and exotic arbuscular mycorrhizal fungi. Ecology 84, 2292–2301.Google Scholar
  21. Koide R 1985 The nature of growth depressions in sunflower caused by vesicular-arbuscular mycorrhizal infection. New Phytol. 99, 449–462.Google Scholar
  22. Koide R 1991a Density-dependent response to mycorrhizal infec-tion in Abutilon theophrasti Medic. Oecologia 85, 389–395.Google Scholar
  23. Koide R 1991b Nutrient supply, nutrient demand and plant response to mycorrhizal infection. New Phytol. 117, 365–386.Google Scholar
  24. Koske R E and Gemma J N 1989 A modified procedure for staining roots to detect VA mycorrhizas. Mycol. Res. 92, 486–488.Google Scholar
  25. Marschner H 1995 Mineral Nutrition of Higher Plants. 2nd ed. Academic Press, San Diego, CA. pp. 490–507.Google Scholar
  26. Maffia B 1997 Arbuscular mycorrhizae alter intraspecific competition. Ph.D. Dissertation. University of Miami, Coral Gables, FL.Google Scholar
  27. Mengel D B and Barber S A 1974 Development and distribution of the corn root system under field conditions. Agron. J. 66, 341–344.Google Scholar
  28. Moora M and Zobel M 1996 Effect of arbuscular mycorrhiza in inter-and intraspecific competition of two grassland species. Oecologia 108, 79–84.CrossRefGoogle Scholar
  29. Peng S, Eissenstat D M, Graham J H, Williams K and Hodge N C 1993 Growth depression in mycorrhizal citrus at high-phosphorus supply. Plant Physiol. 101, 1063–1071.PubMedGoogle Scholar
  30. Ronsheim M L and Anderson S E 2001 Population-level specificity in the plant-mycorrhizae association alters intraspecific interactions among neighboring plants. Oecologia 128, 77–84.CrossRefGoogle Scholar
  31. Sanders F E and Tinker P B 1973 Phosphate flow into mycorrhizal roots. Pest. Sci. 4, 384–395.Google Scholar
  32. Sieverding E and Howeler R H 1985 Influence of species of VA mycorrhizal fungi on cassava yield response to phosphorus fertilization. Plant Soil 88, 213–221.CrossRefGoogle Scholar
  33. Smith S E and Read D J 1997 Mycorrhizal Symbiosis. 2nd ed. Academic Press, San Diego, CA. pp. 379–408.Google Scholar
  34. SPSS 2000 SPSS 10.1.0 for Windows. SPSS Inc. Chicago, IL.Google Scholar
  35. Statistix 2000 Statistix 7.0 Analytical software. Statistix Inc. Tallahassee, FL.Google Scholar
  36. Wada K 1980 Mineralogical Characteristics of Andisols. In Soils with Variable Charge. <nt>Ed.</nt> B K G Theng. pp. 87–107. New Zealand Society of Soil Science, Aukland, New Zealand.Google Scholar

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • Michelle S. Schroeder
    • 1
    • 2
  • David P. Janos
    • 1
  1. 1.Department of BiologyUniversity of MiamiCoral GablesUSA
  2. 2.Department of Crop SciencesNorth Carolina State UniversityRaleighUSA

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