Submitted to: North American Alfalfa Improvement Conference
Publication Type: Proceedings
Publication Acceptance Date: May 20, 2008
Publication Date: June 1, 2008
Citation: Mott, I.W., Peel, M., Larson, S.R., Boe, A. 2008. Genetic Variation Within and Among Collections of Falata Alfalfas. North American Alfalfa Improvement Conference. Technical Abstract: Yellow-flowered alfalfa (Medicago sativa subsp. falcata) persists in low precipitation rangeland and grassland environments. The origin of Medicago includes Russia, Mongolia, Scandinavia, and China (Hansen, 1909; Lesins and Lesins, 1979). The presence of legumes improves rangelands and grasslands by increasing soil nitrogen, improving wildlife habitat, and providing valuable forage for cattle and other wildlife. Stands of naturalized falcata alfalfa on the Smith ranch near Lodgepole, South Dakota have persisted for decades under harsh conditions and grazing (Smith, 1997). A yellow-flowered alfalfa, believed to have spread from the ranch, currently populates a region of the Grand River National Grassland (GRNG) in South Dakota. Original collections of this alfalfa from the GRNG and selected PI's from the National Plant Germplasm System (NPGS) have been evaluated for biomass production, growth habit, flower color and persistence. We used simple sequence repeats (SSR) and amplified fragment length polymorphisms (AFLP) DNA markers to characterize the genetic diversity within and among a subset of these collections and common alfalfa cultivars. Included in the study were 43 half-sib families from the GRNG; 45 accessions from NPGS; alfalfa cultivars 5454, SD201, Vernal; Bud Smith (seed originating from Bud Smith ranch); and two accessions of Medicaga truncatula. Eight plants were used to represent each collection, PI, and cultivar. Twenty-four alfalfa SSR primer pairs were used to produce 183 scored fragments. Two selective amplification primer pairs were used to generate 425 AFLP bands. Variation among collections accounted for 28% (AFLP) and 23% (SSR) of the total variation; whereas variation within collections accounted for 72% (AFLP) and 77% (SSR) of the total variation. The SSR data cluster all of the GRNG genotypes in one group, and show seed from the Smith ranch grouping more closely with PI 631635 (Mongolia) and PI 631620 (India), than with other GRNG collections. The most closely related alfalfa accessions to the GRNG collections were PI 631832 (Romania), PI 631834 (Sweden) and PI 631583 (Switzerland). The AFLP data show that Smith ranch seed is intermediately related to PI 631620 and PI 440537 (from Kazakhstan) and the GRNG collections.