Summary
It is paradoxical that most plants under natural conditions are infected with vesicular-arbuscular mycorrhizal fungi, yet that it is often difficult to demonstrate that infected plants receive any benefit from the association. The costs and benefits of infection are analysed and a hypothesis formulated that infection only yields benefits at times during the life cycle when P demand by the plant exceeds the capacity of the root system. A simulation model is described that suggests that infection density should be more or less constant below a threshold value of root P uptake rate, but that above this value roots should be non-mycorrhizal. More extensive study of mycorrhizas under field conditions is needed to test such predictions.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Amijee, F., Tinker, P. B., and Stribley, D. P., The development of endomycorrhizal root systems. VII. A detailed study of effects of soil phosphorus on colonization. New Phytol.111 (1989) 435–446.
Bethlenfalvay, G. J., and Ames, R. N., Comparison of two methods for quantifying extraradical mycelium of vesicular-arbuscular mycorrhzal fungi. Soil Sci. Soc. Am. J.51 (1987) 834–837.
Douds, D. D., Johnson, C. J., and Koch, K. E., Carbon cost of the fungal symbiont relative to net leaf P accumulation in a split-root VA mycorrhizal symbiosis. Plant Physiol.86 (1988) 491–496.
Dunne, M. J., and Fitter, A. H., The phosphorus budget of a fieldgrown strawberry (Fragaria x ananassa cv. Hapil) crop: evidence for a mycorrhizal contribution. Ann. appl. Biol.114 (1989) 185–193.
Finlay, R. D., Interactions between soil micro-arthropods and endomycorrhizal associations of higher plants, in: Ecological Interactions in soil, pp. 319–321. Ed. A. H. Fitter. Blackwell, Oxford 1985.
Fitter, A. H., Effect of benomyl on leaf phosphate concentration in alpine grasslands: a test of mycorrhizal benefit. New Phytol.103 (1986) 767–776.
Fitter, A. H., Acquisition and utilisation of resources, in: Plant Ecology, pp. 119–139. Ed. M. J. Crawley. Blackwell, Oxford 1986.
Fitter, A. H., An architectural approach to the comparative ecology of plant root systems. New Phytol.106 Suppl., (1987) 61–77.
Gange, A. C., Brown, V. K., and Farmer, L. M., A test of mycorrhizal benefit in an early successional plant community. New Phytol.114 (1990) in press.
Harris, D., and Paul, E. A., Carbon requirements of vesicular-arbuscular mycorrhizae, in: Ecophysiology of VA Mycorrhizal Plants, pp. 93–105. Ed. G. R. Safir. CRC Press, Baton Rouge 1987.
Hayman, D. S., VA mycorrhizas in field crop systems, in: Ecophysiology of VA Mycorrhizal Plants, pp. 171–191. Ed. G. R. Safir. CRC Press, Baton Rouge 1987.
Herold, A., Regulation of photosynthesis by sink activity — the missing link. New Phytol.86 (1980) 131–144.
Hetrick, B. A. D., Mycorrhiza and root architecture. Experientia47 (1991) 355–362.
Iwasa, Y., and Roughgarden, J., Shoot/root balance of plants: optimal growth of a system with many vegetative organs. Theor. Pop. Biol.25 (1984) 78–105.
Jakobsen, I., Vesicular-arbuscular mycorrhizas in field-grown crops. III. Mycorrhizal infection and rates of phosphorus inflow in pea plants. New Phytol.104 (1986) 573–581.
Janos, D. P., VA mycorrhizas in humid tropical ecosystems, in: Ecophysiology of VA Mycorrhizal Plants, pp. 107–134. Ed. G. R. Safir. CRC Press, Baton Rouge 1987.
Koch, K., and Johnson, C. R., Photosynthate partitioning in split root seedlings with mycorrhizal and non-mycorrhizal root systems. Plant Physiol.75 (1984) 26–30.
Koide, R., and Elliott, G., Cost, benefit and efficiency of the vesicular-arbuscular mycorrhizal symbiosis. Funct. Ecol.3 (1989) 252–255.
Koide, R. T., Huenneke, L. F., Hamburg, S. P., and Mooney, J. A., Effects of applications of fungicide, phosphorus and nitrogen on the structure and productivity of an annual serpentine plant community. Funct. Ecol.2 (1988) 335–344.
Kucey, R. M. N., and Paul, E. A., Carbon flow photosynthesis and N2 fixation in mycorrhizal and nodulated faba beans (Vicia faba L.). Soil Biol. Biochem.14 (1982) 407–412.
Law, R., and Lewis, D. H., Biotic environments and the maintenance of sex — some evidence from mutualistic symbioses. Biol. J. Linn. Soc.20 (1983) 249–276.
McGonigle, T. P., A numerical analysis of published field trials with vesicular-arbuscular mycorryhizal fungi. Funct. Ecol.2 (1988) 473–478.
McGonigle, T. P. and Fitter, A. H., Growth and phosphorus inflows ofTrifolium repens L. with a range of indigenous vesicular-arbuscular mycorrhizal (VAM) infection levels under field conditions. New Phytol.108 (1988) 59–65.
McGonigle, T. P., and Fitter, A. H., Ecological consequences of arthropod grazing on VA mycorrhizal fungi. Proc. Roy. Soc. Edinb.94B (1988) 25–32.
Nemec, S., VA mycorrhizal in horticultural systems: in Ecophysiology of VA Mycorrhizal Plants, pp. 18–41. Ed. G. R. Safir. CRC Press, Baton Rouge 1987.
Pitelka, L. F., Stanton, D. S., and Peckenham, M. O., Effects of light and density on resource allocation in a forest herbAster acuminatus (Compositae). Am. J. Bot.67 (1980) 942–948.
Pirozynski, K. A., and Malloch, D. W., The origin of land plants: a matter of mycotrophism. Biosystems6 (1975) 153–164.
Plenchette, C., Fortin, J. A., and Furlan, V., Growth responses of several plant species to mycorrhizae in a soil of moderate P fertility. I. Mycorrhiza dependency under field conditions. M. Soil70 (1983) 199–206.
Sanders, F. E., and Tinker, P. B., Phosphate flow into mycorrhizal roots. Pestic. Sci.4 (1973) 385–392.
Sanders, F. E., Tinker, P. B., Dlack, R. R., and Palmerley, S. M., The development of endomycorrhizal root systems. I. Spread of infection and growth-promoting effects with four species of vesicular-arbuscular mycorrhizae. New Phytol.78 (1977) 257–268.
Sanders, I. R., Seasonal patterns of vesicular-arbuscular mycorrhizal occurrence in grasslands. Symbiosis (1990) in press.
Snellgrove, R. C., Splitstoesser, W. E., Stribley, D. P., and Tinker, P. B., The distribution of carbon and the demand of the fungal symbiont in leek plants with vesicular-arbuscular mycorrhizas. New Phytol.92 (1982) 65–87.
Terry, N., and Ulrich, A., Effects of phosphorus deficiency on the photosynthesis and respiration of leaves in sugar beet. Plant Physiol.51 (1973) 43–47.
Trappe, J. M., Phylogenetic and ecologic aspects of mycotrophy in the angiosperms from an evolutionary standpoint, in: Ecophysiology of VA Mycorrhizal Plants, pp. 5–25. Ed. G. R. Safir. CRC Press, Baton Rouge 1987.
Wilson, J. M., Comparative development of infection by three vesicular-arbuscular mycorrhizal fungi. New Phytol.97 (1984) 413–426.
Yost, R. S., and Fox, R. L., Contribution of mycorrhizae to P nutrition of crops growing on an oxisol. Agron. J.71 (1979) 903–908.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Fitter, A.H. Costs and benefits of mycorrhizas: Implications for functioning under natural conditions. Experientia 47, 350–355 (1991). https://doi.org/10.1007/BF01972076
Issue Date:
DOI: https://doi.org/10.1007/BF01972076