Title: Seed rescue from photoperiod sensitive American Joint Vetch (Aeschynomene americana L.) accessions using hydroponic cloning and aeroponics Author
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 6, 2013
Publication Date: N/A
Technical Abstract: American joint vetch, Aeschynomene Americana L. is a self-pollinated tropical pasture legume and the USDA, ARS, PGRCU curates 137 accessions from the United States, S. America, Mexico, Central America, and Zambia. Many accessions in this collection are photoperiod sensitive due to their typical flower and seed production during November through March in Griffin, GA. My objectives were to determine if hydroponic cloning and aeroponic systems can be used to rescue seed from American joint vetch accessions regenerating in the field. Eleven American joint vetch accessions were transplanted to the USDA, ARS, PGRCU regeneration farm in Griffin, GA during the spring of 2012. These accessions were grown throughout the spring, summer and fall. Prior to the first hard freeze, 4 woody and mature vegetative stem cuttings (15-20 cm long) per accession with at least 3 true leaves per cutting were removed from randomly chosen plants that did not produce seeds within each American joint vetch plot. Each of these vegetative cuttings were placed in a hydroponic cloning system box located inside the greenhouse at the end of the growing season during the Fall of 2012. Most of the stem cuttings developed very healthy root systems after 1-2 weeks of cloning. Each stem cutting with well developed roots were placed in an aeroponic system inside the greenhouse. The experimental design was a randomized complete block design with 4 replications. Most of the American joint vetch accessions produced quality seed 1-4 months (late 2012 to early 2013) after growing in the aeroponic system. Eighteen to 1000 quality seed have been successfully harvested from these aeroponically regenerated American joint vetch accessions. Analysis of variance and mean separations will be conducted on the seed data while coefficient of variation and correlations will be analyzed for phenotypic data recorded from field grown plants. These are excellent techniques to rescue photoperiod sensitive American joint vetch accessions for the production of quality seed from field grown non-seed producers. Hydroponic cloning and aeroponic systems will provide useful tools that can be used for many other plant species with similar photoperiod sensitivities and non-seed producing accessions when regenerated in field conditions.