Evaluation of diversity among and within accessions of Illinois bundleflower

Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMillan] is a native herbaceous warm-season perennial legume that has potential as a forage and grain crop. Many research objectives with the species depend on knowledge of available genetic resources, but the diversity in northern accessions of Illinois bundleflower is unknown. Our objective was to test the hypothesis that genetic variation for selected characters exists within and among a set of northern accessions of Illinois bundleflower. From this, we could determine the distribution of variation among the accessions and examine the phenotypic correlations among characters. We evaluated 20 accessions at Becker and St. Paul, MN, and 18 accessions at Sioux Center, IA. Within-accession diversity was determined by a progeny test at Rosemount and St. Paul, MN. Every measured character was influenced by accession (P < 0.05) in at least one location. Therefore, the accessions evaluated can provide much of the genetic diversity needed to develop cultivars adapted to the northern USA. Much of the variation can be explained by latitude of origin. Southern accessions had the greatest forage and seed yield potential, were later maturing, but lacked persistence in Minnesota. Variation (P < 0.05) for characters including seed yield and survival was also found within accessions. Within year and location, average seed crude protein (CP) concentration and seed weight were correlated (average r = 0.71, P < 0.05). Within location in August, forage neutral detergent fiber (NDF) was negatively correlated with leaf fraction (average r = -0.89, P < 0.001), and leaf and pod fraction were negatively correlated (average r = -0.80, P < 0.01).