ABSTRACTSymbioticEpichloëspecies are fungal endophytes of cool-season grasses that can produce alkaloids with toxicity to vertebrates and/or invertebrates. Monitoring infections and presence of alkaloids in grasses infected withEpichloëspecies can provide an estimate of possible intoxication risks for livestock. We sampled 3,046 individuals of 13 different grass species in three regions on 150 study sites in Germany. We determined infection rates and used PCR to identifyEpichloëspecies diversity based on the presence of different alkaloid biosynthesis genes, then confirmed the possible chemotypes with high-performance liquid chromatography (HPLC)/ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) measurements. Infections ofEpichloëspp. were found inFestuca pratensisHuds. (81%),Festuca ovinaL. aggregate (agg.) (73%),Lolium perenneL. (15%),Festuca rubraL. (15%) andDactylis glomerataL. (8%). The other eight grass species did not appear to be infected. For the majority ofEpichloë-infectedL. perennesamples (98%), the alkaloids lolitrem B and peramine were present, but ergovaline was not detected, which was consistent with the genetic evaluation, asdmaW, the gene encoding the first step of the ergot alkaloid biosynthesis pathway, was absent.Epichloë uncinatainF. pratensisproduced anti-insect loline compounds. TheEpichloëspp. observed in theF. ovinaagg. samples showed the greatest level of diversity, and different intermediates of the indole-diterpene pathway could be detected.Epichloëinfection rates alone are insufficient to estimate intoxication risks for livestock, as other factors, like the ability of the endophyte to produce the alkaloids, also need to be assessed.IMPORTANCESevere problems of livestock intoxication fromEpichloë-infected forage grasses have been reported from New Zealand, Australia, and the United States, but much less frequently from Europe, and particularly not from Germany. Nevertheless, it is important to monitor infection rates and alkaloids of grasses withEpichloëfungi to estimate possible intoxication risks. Most studies focus on agricultural grass species likeLolium perenneandFestuca arundinacea, but other cool-season grass species can also be infected. We show that in Germany, infection rates and alkaloids differ between grass species and that some of the alkaloids can be toxic to livestock. Changes in grassland management due to changing climate, especially with a shift toward grasslands dominated withEpichloë-infected species such asLolium perenne, may result in greater numbers of intoxicated livestock in the near future. We therefore suggest regular monitoring of grass species for infections and alkaloids and call for maintaining heterogenous grasslands for livestock.
Epichloë Endophyte Infection Rates and Alkaloid Content in Commercially Available Grass Seed Mixtures in Europe
