Variation for Canopy Morphology in Little Bluestem

Abstract

ABSTRACTLittle bluestem, Schizachyrium scoparium (Michx.) Nash, is a native grass that has been shown to have high levels of genetic variation for traits such as biomass yield, disease resistance, plant height, leafiness, maturity, and seed yield. If high levels of genetic variation exist for these traits, it is likely that it would exist for other traits as well. Thus, the objectives were to describe the variation in traits that contribute to canopy morphology within and among little bluestem parental lines, an F1 plant population, and selected F1 populations. Plants were classified as not upright (NU), upright compact (UC), or upright open (UO) on the basis of their shape. As expected, all parental lines expressed considerable variation for frequencies of discrete morphological traits and for continuous morphological traits. The F1 plant population was characterized by 12.2% NU plants, 22.4% UC plants, and 65.4% UO plants. The selected populations were fixed for several discrete variables, including growth form, lack of lodging, and little or no leaf rust. To fully exploit the genetic variability of little bluestem, it would be necessary to obtain ecotypes from throughout its natural range and breed and select for new genetic variation that could be captured through recurrent selection. Little bluestem is an ideal species for breeding new cultivars and/or germplasm lines for pasture and rangeland renovation, roadside revegetation, wildlife habitat, and recreation areas.