David E. Giannasi

Evolutionary Relationships of the Caryophyllidae Based on Comparative rbcL Sequences

In the long-standing controversy over the Centrospermae (i.e., Caryophyllales) and putatively related orders, comparative sequencing of the chloroplast gene, ribulose-1,5-bisphosphate carboxylase, large subunit (rbcL), shows that the Polygonales and Plumbaginales are not closely related to the Caryophyllales as has been hypothesized, nor are they related to members of the Dilleniidae. The sequence data supports the assignment of independent superorder status to the Caryophyllales and the Polygonales and Plumbaginales. These sequence data further suggest early and independent paths of evolution for the Polygonales and Plumbaginales, and the Caryophyllales.

Chemical composition of North American bee propolis and biological activity towards larvae of greater wax moth (Lepidoptera: Pyralidae)

Bee propolis is a sticky amalgamation of plant resins collected by honeybees (Apis mellifera L.) and used in the hive for filling cracks and repairing combs. Propolis contains a diversity of compounds of plant origin, and is reported to have medicinal, antimicrobial, insecticidal, and phytotoxic properties. We examined the physical and chemical composition of North American samples of bee propolis from several sites in North America and tested for bioactivity against larvae of the greater wax moth (Galleria mellonella L.), a common apiary pest. The amount of methanol-extractable resin in samples from Ohio and Georgia ranged from 24% to 79% by weight. Propolis collected from hives in Ohio was more chemically diverse (over 30 compounds detected by paper chromatography) than material from south Georgia (fewer than 10 major compounds) and contained a lower proportion of methanol-insoluble beeswax. The paper chromatographic surveys revealed little variation in the chemical profile of specific hives over a six-month period and no differences between propolis from adjacent hives. Four flavonoids were identified from propolis collected in Ohio: kaempferol, galangin, 3,3′-dimethoxyquercetin and 3-methoxykaempferol. When mixed into artificial diet, fractionated propolis reduced larval growth of the greater wax moth, but not dramatically. An array of phenolics reported from propolis (caffeic acid, chrysin, ferulic acid, galangin, kaempferol, and quercetin) were bioassayed individually for effects on larvae, but none reduced larval growth at the concentrations tested, suggesting that wax moths are tolerant of some phenolics in their diet.

Foliar flavonoids of eastern North AmericanVitis (Vitaceae) north of Mexico

Twenty-one flavonoid glycosides were isolated from the leaves of 22 North AmericanVitis L. taxa, representing two subgenera and five series. Three chemical groups were evident: one producing flavonols, flavones, and C-glycosylflavones, a second producing flavonols and flavones, and a third producing only flavonols. These three chemical groups did not correspond to any of the subgeneric groupings based on morphology. However, flavonoid distributions within series in each subgenus correlate well with morphological data. Parallel flavonoid evolution within each series is thought to account for this lack of subgeneric and interserial flavonoid distinction. The flavonoid data indicate that seriesCordifoliae of subgenusVitis, particularlyV. vulpina L., is the most closely related group to subgenusMuscadinia (Planch.)Rehder, and represents an evolutionary link between the two subgenera.

Phylogenetic relationships of theJuglandaceae

A cladistic analysis of molecular data from the chloroplast generbcL was used to examine the taxonomic relationships of the walnut family (Juglandaceae). In addition, chemical and morphological data from a previous study byHufford (1992) were incorporated, expanded, and analyzed independently and in combination with the molecular data. The results of these analyses suggest that theJuglandaceae are more closely related to theFagaceae, Betulaceae, Casuarinaceae, andUrticaceae and their relatives (sensuCronquist 1981) than they are to theAnacardiaceae (sensuThorne 1983). However, sequence data fromrbcL also suggest a relationship between the higherHamamelidae and certain families in theRosidae sensuCronquist 1981 (such asRosaceae andRhamnaceae), an outcome which would add credence to the widely accepted view of the polyphyletic nature of theHamamelidae.

Phylogenetic Inference in Velloziaceae Using Chloroplast TrnL-F Sequences

Abstract The chloroplast trnL-F region was sequenced for 20 species of Velloziaceae sensu stricto plus Acanthochlamys and representative species of Cyclanthus (Cyclanthaceae) and Pandanus (Pandanaceae) as outgroups. Phylogenetic analysis of the trnL intron and trnL-F intergenic spacer placed the Asian Acanthochlamys as a distant but well-supported sister-group to a monophyletic Velloziaceae sensu stricto. Within the Velloziaceae, the subfamily Barbacenioideae sensu Menezes is well supported as monophyletic, in agreement with chromosomal and morphological data, while the subfamily Vellozioideae may be paraphyletic. At least two of the currently recognized genera within the Barbacenioideae (Aylthonia and Barbacenia) appear to be paraphyletic or polyphyletic as currently delimited, while the genus Burlemarxia appears to have arisen recently within a subgroup of Barbacenia. These results appear most consistent with the inclusion of all or almost all of the taxa of the Barbacenioideae within a broadly delimited genus Barbacenia. Within the subfamily Vellozioideae, trnL-F data are consistent with the segregation of the South American Nanuza from Vellozia as a distinct genus, while the South American species sometimes placed in Xerophyta are not distinct from Vellozia. Communicating Editor: John V. Freudenstein

Genetic variation and species boundaries in Calopogon (Orchidaceae)

Abstract Morphological and habitat similarities among the five species of the terrestrial orchid genus Calopogon have led to nomenclatural and taxonomic confusion. The taxa are marked by subtle character differences and little apparent reproductive isolation. Here we investigate allozyme diversity at the species level and the partitioning of genetic variation within and among species and their populations. Genetic identities are used to define species boundaries and suggest phylogenetic relationships. All five species of Calopogon maintain high levels of allozyme variation within their populations (P = 50.0%−94.4%, AP = 2.67–3.32, He = 0.11–0.43). Calopogon oklahomensis, an autotetraploid that appears to have undergone gene silencing at 13 of its 19 polymorphic loci, consistently had the highest genetic diversity values. Calopogon multiflorus, which has the most restricted range and rarest occurrence, had the lowest mean genetic diversity values. In C. oklahomensis, C. pallidus and C. tuberosus most of the genetic variation exists within rather than among populations (GST = 0.037–0.085). The UPGMA phenogram generated using genetic identity data has three phenetic groups and supports designation of the taxa as separate species. The data suggest that C. oklahomensis most closely resembles the basal extant taxon within Calopogon.

SYSTEMATIC IMPLICATIONS OF FLAVONOID PIGMENTS IN THE FERN GENUS HEMIONITIS (ADIANTIACEAE)

The closely related fern generaHemionitis L. andGymnopteris Bernhardi are separated primarily on differences in leaf architecture and venation. Studies indicate that these characters are highly variable and unreliably diagnostic. Further, the type species of the two genera readily hybridize with each other. Spore morphology, as exhibited by SEM, does not support the traditional alignment of the species in these two genera: some species ofHemionitis andGymnopteris have the same rugose to papillate spores, while other species from both genera possess crested spores. The flavonoid chemistry of these taxa coincides with spore type, i.e., taxa from both genera which possess crested spores produce kaempferol and quercetin 3-0-glycosides, while species with tuberculate spores produce only quercetin 3,4′-0-glycosides. The spore and chemical data suggest a realignment of these taxa within a single genus, which would avoid the rather tenuous dependence on a single vegetative character for generic distinctions.

Chemosystematic studies in the chrysobalanaceae. I. Flavonoids in Parinari

A survey of flavonoids in 31 Asian, African and Neotropical species of Parinari showed a predominance of flavonol glycosides based on myricetin, quercertin, and kaemp-ferol. The African taxa split into two groups based on the presence or absence of myricetin glycosides. The Neotropical taxa, a complex of closely related species, are chemically very similar to each other and lack myre⪘etin, as does one group of African species. The Asian taxa are similar to the Neotropical ones in their flavonoid patterns and lack of myricetin glycosides. The presence of myricetin considered a primitive flavonoid character, suggest that te African species pro-ducing this flavonol represent a primitive nucleus eastward and westward ex-pansion to two myricetin-lacking phytogeographic lines. This hypothesis is in agreement with current proposals for geographic evolution in the Chrysobalanaceae.

Flavonoids and the taxonomy of Cercis.

Flavonoids of 11 samples of Cercis, comprising seven species, were isolated and identified. Only 3-O-monoglycosides of kaempferol, quercetin and myricetin were obtained. Bauhinia (the largest genus in tribe Cercideae) is akin to Cercis because flavones are rarely found in the former. On the other hand, species of Bauhinia often present glycosides of isorhamnetin and a wider diversity of glycosides, and only rarely present myricetin. The frequent occurrence of this flavonol and the simpler flavonoid profile of Cercis may reflect a greater antiquity of Cercis as compared with Bauhinia. With the exception of C. canadensis var. mexicana, Cercis taxa from xerophytic habitats did not yield kaempferol glycosides in detectable amounts, as opposed to taxa from mesophytic habitats. The results obtained are consistent with proposals of merging C. reniformis into synonymy of C. occidentalis, as well as the recognition of two North American species, C. canadensis and C. occidentalis, and the recognition of the Asian C. gigantea.

Paleobiochemistry of North American fossil Liriodendron sp.

Abstract Organic geochemical analyses are presented for a fossil Liriodendron sp. from the Miocene, Clarkia Flora of Northern Idaho. Flavonoid profiles determined for the fossil and two extent species of Liriodendron (L. chinense and L. tulipifera ) confirm the generic status of the fossil material, but owing to a generic uniformity in flavonoid composition, fail to resolve taxonomic affinities at the species level. Steroid and other cycloalkane-alkene profiles indicate that the fossil taxon has a greater chemical similarity with L. chinense than L. tulipifera , despite the general leaf outline similarity between the fossil species and extent L. tulipifera . The morphologic and chemical data are interpreted as evidence for mosaic evolution within the genus, and the non-canalization of character states in some Miocene species.