Insights into the species delineation and population structure of Solidago shortii (Asteraceae) through morphometric analysis

Short\u27s goldenrod, Solidago shortii (Asterceae), is extant from a single locality in Blue Licks, Kentucky. Field studies demonstrated that this endemic is morphologically variable taxon, inspiring two questions. First, is the taxon known as S. shortii from Blue Licks the same species as originally described by Torrey and Gray from an extirpated population at the Falls of the Ohio River, Kentucky? Second, what is the extent of the morphological variation within and among populations of Short\u27s goldenrod at Blue Licks? These questions were addressed through Principal Components Analysis (PCA), Discrimination Function Analysis (DFA), and standard whole-plant herbarium specimen comparisons. Whole-plant comparisons with other members of Solidago subsection Triplinervae revealed diagnostic characters suitable for the delineation of S.shortii. All speciments of S. shortii from both the Blue Licks and Falls of the Ohio localities shared diagnostic character states. For morphometric purposes, speciments representing two sympatric goldenrod species (S. ulmifolia and S. nemoralis) and one close phylogenetic relative (S. canadensis var. scabra) were sampled from the same locality as S. shortii. Vegetative and floral characters were analyze for all four taxa. Specimens of S. shortii from the Blue Licks vicinity formed a continuous cluster in PCA with specimens from the Falls of the Ohio, a cluster which was distinct from those formed by the other three species. In DFA, the Falls of the Ohio specimens were imbedded in the cluster formed by the Blue Licks specimens. Thus, the taxon at Blue Licks is indeed S. shortii, as established by morphometric analysis and whole-plant comparisons. In terms of interspecific variation, S. shortii at Blue Licks exhibited a similar or greater range of variation than either of the two more common Solidago taxa found at Blue Licks, S. canadensis var. scabra and S. nemoralis. The range of morphological variation exhibited by S. ulmifolia was slightly greater than that of S. shortii. These data also indicate a greater variability within and among Blue Licks populations of S. shortii than otherwise might be expected for a species of highly restricted distribution, and have major implications regarding management policies

Flavonoid chemistry of the generic segregates Ascyrum and Crookea of Hypericum

Leaf flavonoids were isolated and characterized from the seven taxa of Hypericum, formerly segregated as Ascyrum and Crookea. These included flavonol 3-glycosides based on quercetin and kaempferol and flavone-O-glycosides and C-glycosides based on apigenin and luteolin. The flavonoid data do not indicate that the taxe of Ascyrum and Crookea form a single coherent group and hence support their merger with Hypericum

Differences in rates of tyrosine aminotransferase deinduction with cyclic AMP and glucocorticoids

As an indirect test of the possibility that cyclic AMP produces its stimulatory effects on the synthesis of tyrosine aminotransferase (L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5) by stabilizing its mRNA, the kinetics of decline in the rate of synthesis of this enzyme was measured in rat hepatoma cells following inducer removal or addition of RNA synthesis inhibitors. In all cases in which cells were previously exposed to cyclic AMP, the decline in enzyme synthesis after removal of inducer or addition of inhibitors of RNA synthesis was 4 to 5 times more rapid than in cells exposed to a glucocorticoid (dexamethasone) which also induces the aminotransferase. Thus, it seems unlikely that cyclic AMP had been acting by stabilizing the mRNA that directs the synthesis of the aminotransferase. Possible explanations for these paradoxical results are suggested. A more rapid decline in enzyme synthesis was also seen in cells induced with both cyclic AMP and glucocorticoid, suggesting direct interaction between the two inducers

High levels of seed inviability among seven populations of the endangered Short’s goldenrod (Solidago shortii – Asteraceae)

The physical conditions of mature seeds were examined from representatives of six Kentucky populations and one Indiana population of the endangered species Short\u27s goldenrod (Solidago shortii, Asteraceae.) A random sample of seeds from the Kentucky populations revealed the majority (71%-99%) were incapable of successful seedling development, being damaged due to either an insect predator or to unsuccessful fertilization or embryo abortion. Successful seedling development from phenotypically normal seeds ranged from 71% to 96% in the sampled Kentucky populations. The majority of the damaged seeds were necrotic, ranging from 62%-90%. The Indiana population exhibited the lowest level of herbivory (2%) observed for the species. Two congener goldenrod species (S. canadensis var.altissima and S.nemoralis) found growing either within or adjacent to three populations of Short\u27s goldenrod exhibited lower levels of necrosis and higher levels of herbivory. A third congener species (S.gigantea) exhibited equal levels of the two seed conditions (herbivory and necrosis). The influence of seed inviability upon the persistence of natural populations of Short\u27s goldenrod is at present unknown

Molecular analysis of Solidaster cv. Lemore, a hybrid goldenrod (Asteraceae)

Analysis of nuclear nbosomal ITS and ETS sequence data was used to assess the relationships of the garden ornamental Solidaster cv Lemore, a cultivar that was at one time believed to be an intergeneric hybrid (Solidago × Aster). Part of the analysis involved assessment of the generic placement of one of its putative parents, the Upland White Aster, Solidago ptarmicoides Because of its superficial external appearance this species is still often treated as an Aster, although there is evidence from several sources that suggests it should be classified within Solidago. Phylogenetic analysis of the combined ITS and ETS sequence data showed that there was strong support for the inclusion of S. ptarmicoides within Solidago, based on its placement in a well supported clade composed of all other sampled species of the genus. The ITS sequence data of Solidaster showed evidence of a hybrid origin based on the presence of several intraindividual base pair polymorphisms. Cloning experiments recovered two different individual ITS sequences, one identical to that obtained from S. ptarmicoides and a second that matched sequences obtained for S canadensis Thus DNA sequence data suggested that Sohdaster cv. Lemore is a hybrid goldenrod that involved a cross between S. ptarmicoides and S. canadensis The data further indicated that another possible candidate, Euthamia graminifolia, is not a parent of Solidaster. Also notable was the striking lack of sequence divergence for ITS and ETS among species of Solidago, suggesting that estimation of phylogenetic relationships within the genus will require more rapidly evolving markers