Yield increase induced by the fungal root endophyte Piriformospora indica in barley grown at low temperature is nutrient limited

The fungal root endophytes Chaetomium globosum, Epicoccum nigrum and Piriformospora indica have value as biocontrol and biofertilising organisms in barley, but have not been well tested at low temperatures. This study assessed the efficacy of the endophytes on barley varieties grown under low temperature stress with variable nutrient input. Seed from three cultivars of spring barley were inoculated with one of the three fungal root endophyte isolates - C. globosum, E. nigrum or P. indica - and grown in low temperature under higher and lower nutrient input regimes. Compared with the control, for P.indica-inoculated plants with the higher nutrient input, flowering was earlier and grain dry weight significantly greater for all barley varieties by a mean of 22 %. The nitrogen and carbon content of the grains did not differ significantly between treatments. Chaetomium globosum and Epicoccum nigrum conferred no significant benefits under either nutrient regime. Piriformospora indica is amenable to axenic culture, sporulates readily and can be multiplied rapidly, suggesting that it could be developed as an effective crop treatment in low temperature stressed barley and may have the potential to increase crop yield in colder growing conditions provided that adequate nutrients are supplied.