Effect of phosphorus application on the contents of amino acids and reducing sugars in the rhizosphere and VA mycorrhizal infection of white clover

Abstract

Abstract Vesicular-arbuscular (VA) mycorrhizae accelerate the phosphorus (P) uptake and growth of plants especially in soils with low phosphorus content (Gerdemann 1968; Mosse 1973). Application of phosphate fertilizer to soil, on the contrary, decreases the percentage of infection of roots with VA mycorrhizal fungi (Daft and Nicolson 1966; Mosse and Bowen 1968; Hayman et al. 1975) and inhibit the ameliorating effect on plant growth (Porter et al. 1978; Thomson et al. 1986). The decrease in the percentage of infection with increasing phosphorus concentration may be due to a reduction of fungal growth in soil, inhibition of penetration to roots, and fungal growth within roots. There is little information about the inhibition of mycorrhizal infection at high phosphorus level and also about the compounds which are required for the growth of hyphae.