Submitted to: International Symposium on Fungal Endophytes of Grasses
Publication Type: Proceedings
Publication Acceptance Date: 2/1/2007
Publication Date: 3/25/2007
Citation: Clement, S.L., Elberson, L.R., Kynaston, M. 2007. High Neotyphodium infection frequencies in tillers and seed of infected tall fescue plants, pp. 49-52. Proceedings of the 6th International Symposium on Fungal Endophytes of Grasses (A.J. Popay and E.R. Thom, eds.). New Zealand Grassland Association, Dunedin, New Zealand. Interpretive Summary: This Proceedings chapter for a forthcoming conference on fungal endophytes of temperate grasses details the results of a three year project on retention of these fungi during the course of grass seed regneration activities at the USDA-ARS seedbank at Pullman, Washington. This seedbank is one of the world's largest, maintaining over 17,000 accessions of temperate grasses for U.S. and world agriculture. The genetically diverse endophytes (called Neotyphodium fungi) that exist in these grass accessions are very important to breeders and scientists in the U.S. and overseas who require new strains to endow grass cultivars with stress resistance. And because many existing grass cultivars harbor endophytes that produce alkaloids toxic to grazing livestock, seedbanks like the Pullman facility have become more important as a possible source for nontoxic endophyte strains. Therefore, curators at this seedbank must preserve this important microbial germplasm. This research is important because it demonstrates that seed regeneration activities at the Pullman seedbank are optimal for preserving viable Neotyphodium endophytes.
Technical Abstract: This research quantified frequencies of Neotyphodium infected (E+) tillers and mature seed from field-grown E+ plants of two wild tall fescue accessions from Morocco and Sardinia, Italy. Tiller infection rates were 100% (n = 50 from 10 E+ plants/accession) for each accession and over 99% of the seed (n = 2,394) from E+ plants of both accessions harbored viable Neotyphodium endophyte. Germination rates for E+ seed were 93.8% (Morocco accession) and 97.8% (Sardinia). These results indicate that E+ wild tall fescue plants are capable of near perfect vertical transmission of viable endophyte into seed. They also suggest that current seed-regeneration protocols at the USDA-ARS Western Regional Plant Introduction Station, Pullman, Washington USA, are not detrimental for retaining viable endophytes in grass seed.