Morphology and Genetics of Biomass in Little Bluestem

Abstract

Little bluestem [Schizachyrium scoparium (Michx.) Nash] was the most important dominant species of uplands in the tallgrass prairie. Presently, it is a dominant species, most significantly on coarse‐textured soils, in the mixed‐grass prairie region of the United States and Canada. This wide geographical adaptation to dry soils suggests little bluestem has potential for biomass production in areas unsuitable for most other grass species in the North American steppe. Primary objectives of this research were to (i) describe the morphology and determine the distribution of biomass among main stem and axillary components of little bluestem, and (ii) determine genetic variation for morphology and biomass production in ‘Camper’ little bluestem. Morphological analysis was conducted on tillers collected from natural populations in South Dakota and Montana and from swards of Camper and ‘Badlands’ ecotype in eastern South Dakota. Sixteen genotypes of Camper were evaluated for three years at two locations for determination of genotypic variation for biomass and biomass components. Quadratic models explained relationships between phytomer position and leaf and internode lengths and mass of individual phytomers of natural and selected populations. Genotypic variation occurred for phytomers per tiller, tillers per plant, mass per tiller, axillary branches per tiller, and biomass (range: 102–387 g plant−1). However, the correlation between locations for biomass was not significant for genotypes due to genetic variation for phenotypic plasticity. High frequency of survival over two winters for all genotypes indicated Camper has adequate winter hardiness to serve as a source population for cultivar development for biomass in the northern Great Plains.