Submitted to: International Neotyphodium Grass Interactions
Publication Type: Proceedings
Publication Acceptance Date: 3/15/2004
Publication Date: 5/23/2004
Citation: Clement, S.L., Youssef, N.N., Bruehl, G.W., Kaiser, W.J., Elberson, L.R., Bradley, V.L. 2004. Effect of different storage temperatures on grass seed germination and neotyphodium survival. In: Kallenbach, R., Rosenkvans, C.JR, Lock, T.R., editors. Proceedings 5th International Symposium on Neotyphodium/Grass Interactions. No. 511. Interpretive Summary: This long term study was conducted to identify optimal storage temperatures to maintain high fungal endophyte (Neotyphodium) viability and seed germination in grass seed stored in the seed bank of the USDA, ARS Western Regional Plant Introduction Station, Pullman, Washington. After eight years of storage at 20 C, germination of tall fescue, perennial ryegrass, and wild barley seed lots declined from 97-99% to 23.3-50%. Germination rates for seed stored at 4 and '10 C for eight years remained above 91% (tall fescue, perennial ryegrass) and 81% (wild barley). Neotyphodium viability was markedly reduced or lost at 20 C, but was greater than 96% in seed of perennial ryegrass and wild barley stored at 4, -10, and '196 C. Endophyte viability in tall fescue seed was generally retained at these cold temperatures. Results indicate that seed storage conditions (4 C) of the Pullman seed bank are suitable for the long-term preservation of viable Neotyhodium endophyte in grass seed.
Technical Abstract: The U.S. temperate grass collection is stored and maintained by the USDA, ARS Western Regional Plant Introduction Station in Pullman, Washington. This collection of about 18,000 accessions includes fungal endophyte infected-grasses that could offer diverse endophytes for grass improvement programs and basic research. Grass endophytes are important to breeding programs because they can provide resistance to pests and help grasses withstand drought conditions. It was important to conduct this research because it was not known if seed storage temperatures at the Plant Introduction Station were suitable to preserve endophytes in seed and maintain high rates of seed germination. The results from this eight year study showed that high rates of endophyte viability and seed germination were retained if tall fescue, perennial ryegrass, and wild barley seed were stored at 4, -10, and '196 C. Endophyte viability and seed germination were markedly reduced when seed was stored at room temperature (20 C). This research accomplished its goal by demonstrating that seed storage conditions (4 C, 30% relative humidity) at the Plant Introduction Station are suitable for the long-term preservation of viable endophyte in grass seed.