Response of kidney bean to arbuscular mycorrhizal inoculation and mycorrhizal dependency in P and Zn deficient soils

Since most of the Central Anatolian soils are P and Zn deficient, mycorrhizae may help plants to obtain sufficient nutrients from the soil without the need to apply additional chemical fertilizers. As far as is known, some plants are strongly mycorrhizal dependent for P nutrition, but less is known about the mycorrhizal dependence with Zn nutrition. Hypotheses were tested under P and Zn deficient soils to find out whether kidney bean plants are mycorrhizal dependent or not. Kidney bean (Phaseolus vulgaris L.) plants were grown for 8 weeks in two widely distributed calcareous clay soils with low nutrient content from Central Anatolian Sultanonu and Konya soils (sterilized by autoclaving). The experiment was conducted with three levels of phosphorus (0, 25, 125 mg P kg(-1) soil), and two rates of Zn (0 and 5 mg Zn kg(-1) soil) Two selected arbuscular mycorrhizal (AM) species (Glomus mosseae and G. etunicatum) were inoculated. In the Sultanonu soil, mycorrhizal inoculation increased plant growth and P and Zn uptake. The positive effect of mycorrhizal inoculation on plant P content and uptake was found to be higher when higher levels of phosphorus were applied. The soil from Konya with a high concentration of boron inhibited normal growth of kidney bean plants. Mycorrhizal root colonization was different with mycorrhizal inoculation. Root colonization was not affected by P and Zn application, but it has been shown that the plant is strongly dependent on P nutrition, especially at low P application levels. However, although mycorrhizal inoculation increased plant concentration of Zn, plants were less dependent on Zn nutrition.