Morphology and Genetics of Biomass in Little Bluestem.

Little bluestem [Schizachyrium scoparium (Michx.) Nash] was the most important dominant of uplands in the tallgrass prairie. Presently, it is a dominant, most significantly on coarse-textured soils, in the mixed-grass prairie region of the USA and Canada. This wide adaptation to dry and shallow soils suggests little bluestem has potential for biomass production in areas unsuitable for most other grass species in the North American steppe. Objectives of this research were to (i) describe the morphology and determine the distribution of biomass among main axis and axillary branch components of little bluestem, and (ii) determine genetic variation for morphology and biomass production in the cultivar Camper little bluestem. Natural populations from South Dakota and Montana, Camper, and the selected population Badlands ecotype displayed similar morphological patterns. Quadratic models explained relationships between phytomer position and leaf and internode lengths and mass of individual phytomers. Genetic variation occurred among genotypes for morphology (e.g., number of tillers per plant) and biomass production from a single annual harvest during October at two locations in eastern South Dakota. However, the correlation between locations was not significant for genotypes due to genetic variation for phenotypic plasticity. Survival over three winters was high for all genotypes, indicating Camper has adequate winter hardiness to serve as a promising source population for cultivar development for biomass production in the northern Great Plains.