Monday, November 13, 2006 - 2:00 PM

Viability of an accelerated germ response of fungal inoculated Astragalus utahensis seed in soil.

Sean Eldredge1, Bradley Geary2, Gardner John1, and Scott Jensen3. (1) Brigham Young Univ., Provo, UT 84604, (2) Brigham Young Univ, Provo, UT 84604, (3) USDA Forest Service, US Forest Service Shrub Lab, Provo, UT 84401

Accelerated germination of hard-seeded arid plants allows maximization of the effectiveness of various seed mixes with potential use in restoration scenarios.  Statistical analyses of laboratory germination tests (P values <.0001 for all comparisons in LS Means) of Astragalus utahensis seed inoculated with Aspergillus spp. (Asp) and Alternaria spp. (Alt) fungi indicate accelerated germination, Alt inoculation over Asp by 55%, and Asp over the control by 22%.  This study delineates the viability of this positive germ response in more complex environments involving interactions with soil media.  Tests are conducted in growth chamber and greenhouse environments by a randomized complete block design.  One week after seedlings begin emerging, replications conducted in a growth chamber show strong positive emergence, labeled the peak survival interval, with mean emergence for Asp, Alt and Control at 42, 32 and 20% respectively.  Greenhouse tests show similar results.  Seedling survival of Asp and Alt was compromised by seedling mortality at this peak survival interval.  Damping off was common among seedlings with the survival response surface showing similarities between treatments indicating disease infestation not related to test fungi.  Control seedlings show die-off coordinated with peak emergence though not as extreme as treatment responses.