VARIATION IN CHROMATOGRAPHIC PATTERNS IN THE TRAGOPOGON DUBIUS-PRATENSIS-PORRIFOLIUS COMPLEX (COMPOSITAE)

Natural populations of the diploid species, Tragopogon dubius, T. pratensis and T. porrifolius, the F₁ hybrids of these species, and the two amphidiploids, T. mirus and T. miscellus, were obtained from the same localities used for previous morphological and cytological studies of the evolutionary relationships of this complex. Inter- and intra-populational comparisons were made utilizing 2-dimensional chromatograms of these taxa. Members of the complex shared a group of 18 flavonoid-type pattern components, no one of which was completely species specific. Therefore, species patterns were expressed for a population rather than an individual with pattern components being expressed as a frequency. Patterns for F₁ hybrids and amphidiploids, expressed in the same manner, were relatable to the parental species. Diploid species and F₁ hybrid patterns were the most variable in areas of greatest sympatry, indicating considerable genetic interchange between species. The distribution of specific components in certain populations was interpreted as chemical introgression. Evidence was presented for separate origins of T. mirus in two localities. The results confirm previous interpretations of the evolutionary relationships in this complex, and when compared to those obtained for Baptisia, they implicate the different breeding systems as important factors in establishing the kind of variation observed.