Chromatographic Recognition of Some Palatable and Unpalatable Subspecies of Rubber Rabbitbrush in and around Utah

Abstract

Paper chromatography is useful in identifying palatable and unpalatable subspecies of rubber rabbitbrush in Utah. Methanol extraction of dried foliar material followed by two-dimensional (n-butanol:acetone:water, 4:1:3; acetic acid:water, 15:85) ascending paper chromatography reveals distinctive patterns for Chrysothamnus nauseosus subspecies albicaulis, salicifolius, graveolens, and consimilis. Patterns for rarer subspecies junceus and hololeucus are not as well defined. Gene exchange between subspecies is demonstrated by chemical markers, the chromatographic spots, in putative hybrids and introgressents. Range utilization of current growth by browsing animals is highest for subspecies albicaulis and salicifolius, less for subspecies graveolens, and least for subspecies consimilis. Populations of other subspecies introgressed by consimilis receive limited browsing. Paper chromatography will make it possible to select palatable subspecies of rubber rabbitbrush for range improvement projects and nonpalatable subspecies for areas where animal use is to be discouraged.