Microorganisms (AMF and PSB) interaction on linseed productivity under water-deficit condition

Abstract

The relationship between arbuscular mycorrhizal fungi (AMF) and their associated bacteria<br />can be has great importance for sustainable agriculture especially in the case of highly<br />mycorrhizal plants such as linseed. To evaluate the possible effect of AMF in association with<br />phosphate solubilizing bacteria (PSB) on linseed plants, a 2-yr factorial experiment was<br />conducted based on a randomized complete block design with three replications at Urmia<br />University, Urmia, Iran (37° 39′ 24.82″ N 44° 58′ 12.42″ E). The treatments included two AMF<br />species (Glomus mosseae, G. intraradices and non-mycorrhizal control), PSB (Pseudomonas<br />putida P13 and non-inoculated control) and various irrigation regimes (irrigation after 60, 120<br />and 180 mm of evaporation from Class A pan). A significant increase in mycorrhizal linseed<br />plants yield indicated the effectiveness of the two AMF species more than bacterial inoculation.<br />The cumulative (second year) soil spores were maximally observed in mycorrhizal (single AMF<br />and dually inoculation) treatments. The reduction in bacterial population was found with an<br />increase in water deficit. Dual infections caused an increase in leaf P content more than the one<br />in PSB and AMF inoculations. Drought stress-induced yield reduction in seed and in oil was<br />significantly compensated by mycorrhizal symbiosis for all irrigation levels. We found over<br />25% increase for seed yield and 30% for oil yield in mycorrhizal plants as well as co-inoculated<br />plants. The yields improvements in mycorrhizal treatments (single and dually inoculated)<br />leading to the highest water use efficiency.