Influence of glucosinolate content of Brassica (Cruciferae) roots on growth of vesicular–arbuscular mycorrhizal fungi

Authors

  • M. G. GLENN,

    1. Department of Biology, Tufts University, Medford, Massachusetts 02155, USA
    2. Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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    • *

      Department of Biology, Seton Hall University, South Orange, New Jersey 07079, USA.

  • F. S. CHEW,

    1. Department of Biology, Tufts University, Medford, Massachusetts 02155, USA
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  • P. H. WILLIAMS

    1. Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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SUMMARY

We tested the hypothesis that failure to establish symbiosis with vesicular-arbuscular (VA) mycorrhizal fungi is correlated with glucosinolate concentrations in Brassica, a representative genus of the Capparales. Brassica campestris and B. napus cultivars (brassica) with a range of glucosinolate concentrations (7–524 μmol g1 f. wt in roots) were grown together with the VA mycorrhizal fungi Glomus mosseae and Gigaspora gigantea in agar. Fungal growth was observed in situ but fungi did not penetrate brassica roots. However, normal germ tube growth of the VA mycorrhizal fungi occurred near brassica roots when compatible hosts grew nearby. These compatible hosts developed normal mycorrhizal infections. These results suggest that brassica roots do not produce a diffusable inhibitor of VA mycorrhizal fungi, but lack a diffusable growth stimulus present near roots of compatible hosts.

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