Genetic Variation for Biomass Production in Prairie Cordgrass and Switchgrass

Abstract

Prairie cordgrass (Spartina pectinata Link.) is tall, rhizomatous, and native to marshes, drainage ways, and moist prairies in North America. Our objectives were to determine genetic variation among cordgrass populations for biomass production, to describe the distribution of biomass among phytomers and between leaf and stem components of cordgrass, to compare biomass production and composition of cordgrass to switchgrass (Panicum virgatum L.), and to determine heritability for biomass production in switchgrass. Seven populations of cordgrass and ‘Cave-In-Rock’, ‘Summer’, and ‘Sunburst’ switchgrass were harvested in October in 2001 through 2004. Mean biomass production across years ranged from 5.1 to 7. 9 Mg ha−1 among cordgrass populations. Yields of cordgrass (6.0 Mg ha−1) were similar to Cave-In-Rock (6.8 Mg ha−1) for the first two years. However production in the fourth year was greater for cordgrass (6.8 Mg ha−1) than Cave-In-Rock (2.0 Mg ha−1). Two cordgrass populations produced more biomass (9.3 Mg ha−1) than Summer and Sunburst (4.8 Mg ha−1) in the fourth year. Leaf comprised 70% of the biomass of cordgrass, and differences occurred among phytomers for leaf and internode traits. Cellulose and hemicellulose concentrations were similar for cordgrass and switchgrass, but cordgrass had higher levels of total N and ash. Narrow-sense heritability estimates for biomass production in Summer and Sunburst switchgrass were 0.6. Biomass production of native warm-season grasses intended for biofuel purposes in the northern Great Plains may be enhanced by selecting among populations of cordgrass and among families within cultivars of switchgrass.