|Smith, Mark -|
Submitted to: North American Alfalfa Improvement Conference
Publication Type: Abstract Only
Publication Acceptance Date: May 6, 2014
Publication Date: May 15, 2014
Citation: Riday, H., Smith, M.A. 2014. Broadening the U.S. alfalfa germplasm base [abstract]. North American Alfalfa Improvement Conference. p. 28. Technical Abstract: Over 4000 alfalfa (Medicago sativa L.) plant introductions (PIs) exist in the USDA-ARS National Plant Germplasm System (NPGS). NAAIC has discussed/proposed pre-breeding efforts to utilize this germplasm for creating pre-commercial alfalfa germplasm. Funding constraints have been one impediment to this effort. This project initiates a collaborative alfalfa pre-breeding program supported through “in-kind” breeding activities (i.e., disease screening, nursery evaluations, seed increases, etc.). The goal is to create publicly available alfalfa germplasms from selections out of the NPGS collection. Current participants are in colder northern American climates; therefore breeding efforts are focused on breeding for such climates. 150 PIs classified as: advanced breeding material, cultivars, or landraces spanning the Eurasian continent in USDA winterhardiness zones up to 7 were chosen. Latitude and longitude for most accessions were absent; using NPGS passport data and the Vavilov Institute database, origin locals with corresponding latitude and longitude were deduced. Plants from each accession were planted at two Wisconsin locations in spring 2013. Plant vigor notes were taken autumn 2013. Initial analysis revealed a multiple regression model of plant vigor score (scale 1-worst to 9-best) with latitude and longitude. The two independent trends were: 1) western Eurasian PIs do better than eastern Eurasian PIs (stronger trend) and 2) southern Eurasian PIs do better than northern Eurasian PIs (weaker trend). Riday and Brummer (2005) observed a similar trend in subsp. falcata germplasm. Future intensive plant evaluation and selection will follow on these nurseries. Other objectives may include: intensive focus on creating a central-Asian breeding pool (Bhandari et al., 2007), using DNA markers to ensure “distinctiveness” of selected germplasm, and exploring climate of origin factors associated with performance. Sampling more genotypes from the best PIs and evaluating additional PIs from key Eurasian regions will likely follow. Any other alfalfa breeding entities are welcome to join this project.