Response of spring wheat cultivars to Glomus clarum NT4 in a P-deficient soil containing arbuscular mycorrhizal fungi
The dependency of four spring wheat cultivars (Triticum aestivum L.) Laura, Columbus, Neepawa and Katepwa on Glomus clarum NT4 in a P-deficient soil containing indigenous arbuscular mycorrhizal fungi (AMF) was assessed in a growth chamber. The wheat cultivars were grown with or without 1.5 g of a monospecific culture of Glomus clarum NT4 for 95 d. The NT4 inoculant had no significant (P < 0.05) impact on the growth or grain yield of Laura or Neepawa, but increased that of Columbus and reduced that of Katepwa. The shoot P or N concentration, or the shoot P use efficiency (PUE) was not affected by AMF inoculation. However, the grain P concentration of Laura was significantly (P < 0.05) greater in the NT4-inoculated plants compared with the control. Increases in the shoot and grain yield of NT4inoculated Columbus were associated with a significant (P < 0.05) increase in the grain PUE of the plants. The % AMF-colonized root was significantly higher in NT4-inoculated Laura, Columbus and Neepawa, but there was no effect on Katepwa. The dependency of the cultivar Columbus on AMF was apparently greater in this soil compared with the other cultivars. These results suggest that the four wheat cultivars not only varied in their susceptibility to AMF colonization, but also in their ability to exploit the rhizosphere AMF community which reflected on plant yield. Key words: Wheat cultivars, Glomus clarum NT4, AMF-cultivar interactions