Fungal root endophytes of a wild barley species increase yield in a nutrient-stressed barley cultivar

Overuse of chemical fertilisers in barley crops carries large economic and environmental costs and can lead to ecosystem degradation and loss of biodiversity. Methods of reducing chemical crop inputs using endophyte treatments have been demonstrated elsewhere. Here, we show that inoculation with six different fungal root endophytes isolated from wild populations of Hordeum murinum ssp. murinum increased grain yield in a nutrient-starved barley cultivar by up to 29 %. Furthermore, we also show that inoculation with the isolates induced increases of up to 70 % in shoot dry weight in the nutrient-starved barley. The greatest increases in grain yield and shoot dry weight were achieved under the lowest nutrient input. Several of the isolates may be new species, and one particularly effective isolate has previously been shown to completely suppress seed-borne infections of barley. Our results indicate that novel fungal root endophytes derived from a wild relative of barley may help to reduce fertiliser inputs while maintaining acceptable yields. If this potential can be realised in field crops it may result in more sustainable, economically cost-effective and environmentally friendly crop treatments and a reduction in chemical fertiliser use.