|Morris, John - Brad|
Submitted to: Journal of Environmental Science and Health
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/16/2012
Publication Date: 1/28/2013
Publication URL: http://handle.nal.usda.gov/10113/58759
Citation: Morris, J.B., Antonious, G. 2013. Glucose, stem dry weight variation, principal component and cluster analysis for some agronomic traits among 16 regenerated Crotalaria juncea accessions for potential cellulosic ethanol. Journal of Environmental Science and Health. 48(3):214-218. Interpretive Summary: The USDA, Agricultural Research Service, Plant Genetic Resources Conservation Unit’s sunn hemp collection has not been studied for ethanol production. Sixteen samples were grown in the field at the USDA facilities in Griffin, GA. Important plant, seed, glucose, and stem dry weight characteristics were recorded from each sample. Several sunn hemp samples produced high glucose concentrations for potential use in cellulosic ethanol as a fuel source.
Technical Abstract: The United State Department of Agriculture (USDA), Agricultural Research Service, (ARS), Plant Genetic Resources Conservation Unit’s (PGRCU) sunn hemp (Crotalaria juncea L.) germlasm collection consists of 22 accessions. Sixteen (16) accessions of the most seed productive were selected. These accessions have not been analyzed for their cellulose content, stem dry weights, related morphological, phenological, and seed reproductive traits which are important to describe the sunn hemp accessions for potential cellulosic ethanol. The objective of this research was to select candidate sunn hemp accessions having high concentrations of cellulose for use as parents in breeding for cellulose. Sixteen sunn hemp accessions including the following Plant Introductions (PI 175106, PI 207657, PI 219717, PI 234771, PI 248491, PI 250485, PI 250486, PI 250487, PI 274948, PI 295851, PI 314239, PI 322377, PI 337080, PI 346297, PI 468956, and PI 561720) were field grown and their mature stems were collected and analyzed for their cellulose content (expressed as glucose concentration) and stem dry weights. In addition, to verify variability, these traits plus morphological, phenological, and seed reproductive traits were analyzed using multivariate and cluster analysis. The accessions, PI 250487, PI 337080, and PI 219717 produced the highest glucose concentrations (859, 809, and 770 mg g-1 stem dry weight, respectively), however PI 468956 produced the highest stem dry weight (258 g). Branching significantly correlated with foliage (r2 = 0.67**) and relative maturity (r2 = 0.60*), while maturity had a significantly negative correlation with seed number (r2 = -0.67**) and plant width (r2 = -0.53*) as well. Seed number significantly correlated with plant width (r2 = 0.57*). Average linkage cluster analysis grouped the 16 sunn hemp accessions into well defined phenotypes with four distinct seed producing groups and one outlier. Based on multivariate and cluster analysis, sufficient variation among these16 sunn hemp accessions exists to support the development of cellulosic ethanol producing cultivars with improved architecture, early maturity, seed yield, glucose concentrations, and stem dry weights.