Mycorrhizal Associates of Pinus patula in South Africa

Growth Stage of Cyperus esculentus Influences Its Allelopathic Effect on Ectomycorrhizal and Higher Plant Species

“…The inhibition of the growth of Boletus maxaria in the present study was less pronounced than that reported by Reinhardt, Khalil, and Bezuidenhout (1996) for unidentified mycorrhizal types on the roots of P. patula seedlings, which were exposed to C. esculentus and two other agronomic weeds. They contended that the inhibition of mycorrhizae, which are considered essential for the successful establishment of pine species (Marais, 1974), represents an indirect allelopathic effect on the forestry species that, although not crippling on its own, may be crucial in determining their resistance to other stress factors. Mycorrhizae are reported to promote the uptake by plants of immobile elements such as phosphorus (P), zinc (Zn) and copper (Cu) (Schenck, 1981;Tinker, 1984;Graham, 1988); increase the efficiency of mineral uptake, thus enhancing plant growth (Marx, 1969).…”

“…Ectomycorrhizae predominate on the roots of forest species, mostly in the form of mushroom-and puffball-producing basidiomycetes and ascomycetes. It has been shown that mycorrhizae help plants to acquire mineral nutrients from the soil (Marx, 1969;Marais 1974;Schenck, 1981;Graham, 1988) and even protect trees from root pathogen infection (Marx, 1973). Parke, Linderman, and Black (1983) found that the fungal symbiont increased the drought resistance of plants by increasing water uptake and/or altering the physiological status.…”