|Camp, Mary - BIOMETRICAL CONSULT. SERV|
|Maxon, Susan - SEED REG.& TESTING BR,AMS|
|Meyer, Gwen - NAT. PLT. MATRLS.CTR.NRCS|
|Davis, Kathleen - NAT. PLT. MATRLS.CTR.NRCS|
Submitted to: Eastern Native Grass Symposium
Publication Type: Proceedings
Publication Acceptance Date: May 1, 2000
Publication Date: July 1, 2000
Citation: KRIZEK, D.T., CAMP, M.J., MAXON, S.R., MEYER, G.C., RITCHIE, J.C., DAVIS, K.M., MCCLOUD, M.L. COMPARATIVE GERMINATION OF 1998 AND 1999 LOTS OF GERMTEC II TREATED EASTERN GAMAGRASS SEED AFTER 28 DAYS IN THE GREENHOUSE AND LABORATORY. EASTERN NATIVE GRASS SYMPOSIUM. 2000. Interpretive Summary: Eastern gamagrass is a native, warm season, perennial bunch grass. It has attracted considerable interest because of its potential use for livestock forage, soil improvement, erosion control, wetland planting, and native plant community restoration. A major obstacle to successful stand establishment of this species is its erratic germination behavior because of severe seed dormancy problems. Moist pre-chill treatment has been traditionally used to break seed dormancy. Recently a proprietary process referred to as Germtec II treatment has been developed. Preliminary greenhouse studies conducted in 1998 indicated that Germtec II primed seed of eastern gamagrass kept in storage at 4C showed a decline in germination within 2 months after receiving the seeds. The present report describes the results of an experiment conducted in 1999 in which comparative germination responses of 1998 and 1999 seed lots were compared over a six month period (March 17-Sept 2). The results obtained were similar to those observed in 1998. Both seed lots given this proprietary seed treatment showed a gradual decline in germination which suggests that the stimulatory effects of this treatment are relatively short-lasting. Laboratory studies involving the use of a staining technique(tetrazolium chloride) indicated that much of the decline in germination could be attributed to a loss of viability. Our findings demonstrate the value of checking seed for viability and the need for further research on seed priming techniques. Our findings should be of particular interest to seed companies and seed testing laboratories.
Technical Abstract: Preliminary greenhouse studies conducted in 1998 indicated that Germtec II primed seed of eastern gamagrass kept in storage at 4C showed a decline in germination within 2 months after receiving the seeds. The experiment was repeated during 1999 in ARS and NRCS greenhouses (GH) using both 1998 and 1999 seed lots. Three trays of 100 seeds each from both lots were planted every 4 weeks from March 17 to September 2. Three germination tests were also conducted on identical dates in April, July, and September in an AMS lab germinator at a day/night temperature of 30/20C (8h photoperiod), using 8 replicates of 50 seeds each. Overall, there was no difference in percentage germination in the GH between the two seed lots, but over time, there were significant differences. Both groups showed a similar pattern, with high initial percentage germination and then a gradual decline. The average 28d percentage germination values in the GH for the two seed lots on April 14, May 12, June 9, July 7, August 5, September 2, and September 30, 1999, were 65%, 38%, 44%, 31%, 34%, 37%, and 37%, respectively. Comparable 28d percentage germination values in the AMS tests on May 12, July 7, and September 30 were 68%, 66% (+7.0% dormant), and 64% (+7% dormant), respectively, for the 1998 seed lot and 75%, 72% (+11% dormant), and 67% normal (+11% dormant), respectively, for the 1999 seed lot. This decline in germination of Germtec II treated seed in both seed lots in 1999 is consistent with that observed in 1998 and suggests that the stimulatory effects of this treatment are relatively short lasting.