FACTORS AFFECTING ARBUSCULAR MYCORRHIZAL DEPENDENCY OF WHEAT GENOTYPES WITH DIFFERENT PHOSPHORUS EFFICIENCIES

Abstract

Three wheat (Triticum aestivum L.) genotypes with high, intermediate and low phosphorus (P) efficiency were grown in a pot experiment with low P supply and adequate P supply either inoculated with the arbuscular mycorrhizal fungus Glomus versiforme or uninoculated. The mycorrhizal dependency of the genotype with relatively high P efficiency was lower than that of the genotypes with lower P efficiencies. Linear correlation analysis revealed that mycorrhizal dependency was primarily controlled by P uptake efficiency. More carbohydrate was translocated to the roots of genotypes with low P efficiency than of those with high P efficiency. In a second pot experiment the same three genotypes were grown in low P soils. Higher hyphal length density arising from carbohydrate translocation led to more P uptake, and this may account for higher mycorrhizal dependency.

ACKNOWLEDGMENTS

We are grateful to the Center for Eco-Environmental Research, Chinese Academy of Science for kindly providing the seeds of the three wheat genotypes. This research was supported financially by the Major State Basic Research Development Programme of the People's Republic of China (project G1999011707) and the National Natural Science Foundation of China (project 39790100).