Festulolium and fungal endophyte associations: host status for Meloidogyne incognita and nematotoxic plant extracts

Abstract

Festulolium hybrids are forage grasses used worldwide in temperate climates. They are associated with the fungal endophyte Epichloë uncinata, which aids in nutrient uptake, drought tolerance, and production of metabolites that protect against parasites and herbivores. Epichloë uncinata produces loline alkaloids, which can deter insect pests. Festulolium has not been widely studied for susceptibility to plant-parasitic nematodes, so Festulolium lines, with and without fungal endophytes, were tested in the greenhouse for host status to the root-knot nematode Meloidogyne incognita. All were poor hosts, regardless of line or endophyte status. Pepper seedlings planted into soil following removal of the Festulolium plants were infected by nematodes, likely because of surviving nematodes from the original inoculation combined with some reproduction on Festulolium. Lolines were found in shoots and roots of all endophyteassociated lines, and some types of lolines in roots increased after nematode infection. Methanolic extracts from roots and shoots of a tested Festulolium line did not inhibit egg hatch, but killed nearly a third of second-stage juveniles whether an endophyte was present or not. Further studies would indicate whether these Festulolium lines aid in suppressing field populations of M. incognita.

Grass–Endophyte Interactions and Their Associated Alkaloids as a Potential Management Strategy for Plant Parasitic Nematodes

“…Epichloë spp. are capable of producing bioactive alkaloids such as peramines, lolines, ergot alkaloids, and indole-diterpenes which protect the host plant from herbivory by animals, insects, and nematodes [1,3,19,30,31]. Endophyte-grass relationships also stimulate the production of phenolic compounds and flavonoids, which can alter the soil microbiome.…”

“…Festulolium hybrids are intergeneric crosses between Festuca pratensis and Lolium perenne and/or Lolium multiflorum . Epichloë uncinata colonises these hybrids [ 1 ] . Epichloë spp.…”

“…Cool-season grasses (family Poaceae) are often associated with claviceptaceous, endophytic fungi in the genus Epichloë [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]; around 30% of Poaceae species have a relationship with Epichloë species [ 4 , 8 ]. Over 600 species from this family are used for foraging and originate from Europe, Africa, and western Asia [ 9 ].…”

Fungal Endophytes and Their Role in Agricultural Plant Protection against Pests and Pathogens

“…Compounds produced by Alternaria , Chaetomium , Cladosporium , Clonostachys Fusarium , Phyllosticta , Piriformospora and Trichoderma strains have been shown to alter the chemical composition of existing metabolites, or increase their production, within the host plant resulting in plant growth promotion or induced resistance to invading nematodes [ 112 , 113 , 120 , 124 , 127 , 128 ]. Alternatively, Acremonium , Diaporthe , Epichloë , Melanconium , Phialemonium and Purpureocillium species can produce bioactive compounds that directly inhibit nematode eggs, juveniles, and females [ 108 , 115 , 121 , 124 , 128 , 129 ]. Strains of Chaetomium , Clonostachys , Phyllosticta and Trichoderma have also been reported as hyper colonizers that can outcompete plant pathogens, including nematodes, for space and nutrients within the plant host [ 110 , 112 , 113 , 123 , 124 ].…”

“…The genus Epichloë contains endophytic fungi best known for forming mutual symbioses with a variety of grass species [ 129 , 133 , 134 ]. Members of this genus colonize grass tissues through hyphal expansion, though this is most prevalent in shoot material [ 133 ].…”