|Youssef, Nadeer - UNIVERSITY OF IDAHO|
|Bruehl, George - RETIRED|
|Kaiser, Walter - RETIRED|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 7, 2000
Publication Date: N/A
Technical Abstract: Preserving Neotyphodium fungi in seed is important because this resource may provide endophyte and alkaloid diversity needed for developing new grass-endophyte combinations for pest resistance and livestock production. However, preservation of this genetic resource requires that seed be stored under optimal conditions for germination and Neotyphodium survival. This research documents germination of tall fescue, perennial ryegrass, and wild barley seed and Neotyphodium survival in seed stored under different temperatures (20, 4, -10, and -196 deg. C) for five (wild barley) and eight (tall fescue, ryegrass) years. At the onset, seed germination rates and endophyte levels were, respectively, 97 percent and 38.6 percent for tall fescue, 99 percent and 98 percent for perennial ryegrass, and 99 percent and 100 percent for wild barley. After eight years of storage, germination of tall fescue and perennial ryegrass seed was maintained (91-100 percent) at 4, -10, and -196 deg. C, but was reduced to 23.3-50 percent at 20 deg. C. After five years of storage at all four termperatures, germination levels of wild barley seed were 77-88 percent. Endophyte viability in infected seed of all three species was significantly reduced or lost after 5-8 years of storage at 20 deg. C. By contrast, endophyte viability (97-100 percent) in ryegrass and wild barley seed was largely unaffected by storage at the three coldest temperatures; however, high endophyte levels (49 percent) in tall fescue was detected only in plants grown from seed stored at -10 deg. C. Storage of endophyte-infected seed under low temperatures will preserve the viability of the endophytes.