Glucose, stem dry weight variation, principal component and cluster analysis for some agronomic traits among 16 regenerated Crotalaria juncea accessions for potential cellulosic ethanol

Abstract

The objectives of this research were to identify candidate sunn hemp accessions having high concentrations of cellulose for use as parents in breeding for cellulose and to determine variability for glucose content and some important agronomic traits among sunn hemp accessions. Since sunn hemp is an under-utilized species, glucose content and agronomic trait variation is essential for the identification of superior sunn hemp accessions for use as potential ethanol for biofuel. Sixteen sunn hemp accessions including the following plant introductions (expressed as glucose concentration) and stem dry weights were studied. “Sixteen sunn hemp accessions including the following plant introductions (expressed as glucose concentration) and stem dry weights were studied.” 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.

Keywords:

• Crotalaria juncea
• principal component
• cluster analysis
• agronomic
• cellulose
• ethanol

Acknowledgments

We thank Ken Manley for his assistance in planting, harvesting, characterizing, and preparing sunn hemp accessions for shipping to Kentucky State University.