Chloroplast DNA Restriction Site Analysis Research Articles

The ghost of hybridization past: niche pre-emption is not the only explanation of apparent monophyly in island endemics.

Summary 1 Published molecular phylogenies show that many plant groups in the Canary Islands are monophyletic despite the fact that the short distance between the islands and Africa should have led to many independent colonization events. 2 Low establishment rates of later migrants owing to niche pre-emption by earlier, already established, colonists could explain these patterns. The apparent monophyly is, however, also compatible with multiple colonizations, with later colonizers making only limited contributions to the total gene pool (and therefore being undetected in the molecular phylogeny) or being wiped out by stochastic processes. 3 Experimental evidence for niche pre-emption and species-specific interactions in plants is weak, with survival and establishment of a newly immigrant species depending on the overall composition of the community, rather than on the presence of a particular ‘ecologically similar’ species. 4 Although niche pre-emption might have contributed to the observed patterns of monophyly, we do not think that phylogeographical data from Macaronesia can be taken as evidence for its action in the geological past.

Evolution of Endemic Sideritis (Lamiaceae) in Macaronesia: Insights from a Chloroplast DNA Restriction Site Analysis

Abstract Sideritis L. subgenus Marrubiastrum (Lamiaceae) comprises 24 species of Macaronesian endemic perennials. The constituent taxa encompass a wide array of life forms that have exploited all ecological zones present in the Macaronesian archipelagos of Madeira and the Canary Islands. Though recently revised, an explicit phylogeny of the subgenus is still lacking. This group is especially intriguing because it exhibits the largest aneuploid series ever reported in oceanic island plants. The present study uses a chloroplast DNA restriction site analysis to elucidate the pattern of evolution within and among the islands. The insular taxa form a strongly supported monophyletic group, indicating a single colonization of Macaronesia. Monophyly of the sections is not supported. Integrating geographical and ecological distribution with the cpDNA phylogeny reveals a pattern of diversification within the islands consistent with adaptive radiation. Most other Macaronesian plant groups studied thus far have diver...

Phylogenetic analysis of Silphium and subtribe Engelmanniinae (Asteraceae: Heliantheae) based on ITS and ETS sequence data

The phylogenetic relationships of Silphium and subtribe Engelmanniinae were examined using DNA sequence data. The internal transcribed spacer (ITS) region and the external transcribed spacer (ETS) region were sequenced for 39 specimens representing the six genera of subtribe Engelmanniinae (Berlandiera, Chrysogonum, Dugesia, Engelmannia, Lindheimera, and Silphium), plus five additional genera identified as closely related to the Engelmanniinae by chloroplast DNA restriction site analysis, and three outgroups. Phylogenetic analysis supported the monophyly of Silphium with Lindheimera as sister. Silphium can be divided into two sections based upon two well-supported clades that correspond to root type and growth form. These results also supported the expansion of subtribe Engelmanniinae to include Balsamorhiza, Borrichia, Rojasianthe, Vigethia, and Wyethia. We hypothesize that subtribe Engelmanniinae originated in Mesoamerica and later radiated to the United States. We suggest that the cypsela complex, which is present in Berlandiera, Chrysogonum, Engelmannia, and Lindheimera, arose only once and was subsequently lost in Silphium.

A Reexamination of North American Satureja s. l. (Lamiaceae) in Light of Molecular Evidence

Satureja s.l. (Lamiaceae) is a large complex (ca. 225 spp.) that is variably treated as comprising from one to as many as 17 genera. The North American representatives are usually assigned toCalamintha, Clinopodium, Micromeria, Piloblephis, orSatureja. A recent chloroplast DNA restriction site analysis indicates that inclusion ofSatureja s.str.,Micromeria, andPiloblephis in the group renders it non-monophyletic. After exclusion of these three genera, a study of morphological variation in the remainder of the complex suggests that it is best treated as three genera, two of which do not occur in North America (Cyclotrichium and “Obtegomeria” [Doroszenko, ined., to be validated else-where]). The third comprises ca. 100 species, 11 of them native to North America north of Mexico. WithSatureja s.str. excluded, the name with priority for the latter genus isClinopodium. The indigenous North American species and their more frequently used synonyms are tabulated. A new combination,Clinopodium chandleri, is made.

Obtegomeria (Lamiaceae), a New Genus from South America

Obtegomeria Doroszenko & P. D. Cantino, a new genus based on Satureja sect. Obtectae Epling & Jitiva, is distinguished from the rest of the Satureja complex by the combination of stiffly ascending, replicate leaves, lower lip of the corolla nearly to fully as long as the tube, and reticulate pollen. Obtegomeria is monotypic and endemic to Colombia. The new combination Obtegomeria caerulescens (Bentham) Doroszenko & P. D. Cantino is provided. The Satureja complex (Satureja L. s.1.) occurs in both the Old and New Worlds and has been variably treated as a single genus (Briquet, 1895-1897; Epling & Jitiva, 1964, 1966) or as many as 17 (Doroszenko, 1985). The authors of this paper have differing views on the classification of Satureja s.1. Using a phenetic approach, one of us recognizes seven genera in the New World (Doroszenko, 1985), while the other has made a phylogenetic argument for recognizing only three (Cantino & Wagstaff, 1998). However, we agree that Obtegomeria warrants segregation. It is separated from the rest of the complex by a substantial phenetic gap and has four probable synapomorphies. There is no evidence that its segregation would render any other genus paraphyletic. Obtegomeria is monotypic and endemic to the Sierra Nevada de Santa Marta in northeastern Colombia. A numerical cluster analysis (Doroszenko, 1985) found Obtegomeria caerulescens to be among the most phenetically distinct species in the complex. It pairs most closely with Piloblephis Rafinesque, a monotypic North American genus that has been excluded from Satureja (Cantino & Wagstaff, 1998) based on a chloroplast DNA restriction site analysis (Wagstaff et al., 1995) that did not include Obtegomeria. The similarity between Obtegomeria and Piloblephis is limited to vegetative features (both are ericoid shrubs with tightly revolute leaves); they differ greatly in inflorescence and floral morpholo-

Phylogenetic relationships in the Crassulaceae inferred from chloroplast DNA restriction‐site variation

A restriction-site analysis of chloroplast DNA from 44 species, representing 19 genera and all six subfamilies of the Crassulaceae was conducted using 12 restriction endonucleases. A total of 969 variable sites was detected, 608 of which were phylogenetically informative and used in parsimony analysis. Estimated values of nucleotide sequence divergence were used to construct a distance tree by the neighbor-joining method. Maximum sequence divergence in the family was ~7%. Different tree inference methods yielded only moderately different topologies. The amount of support for the monophyletic groups obtained in the Wagner parsimony analysis was evaluated by bootstrap and decay analysis. There is very strong support for a basal division of the family, which separates the monophyletic subfamily Crassuloideae from all other taxa. Four of the six traditionally recognized subfamilies are indicated to be polyphyletic. These include the Cotyledonoideae, Sempervivoideae, Sedoideae, and Echeverioideae. The Kalanchoideae and the genera Cotyledon and Adromischus exhibit low levels of cpDNA sequence divergence relative to one another, suggesting a relatively recent radiation. The genera Sedum and Rosularia are indicated to be polyphyletic. Sedum comprises sister taxa of most of the other genera of the family.

Examination of subfamilial phylogeny in Bromeliaceae using comparative sequencing of the plastid locus ndhF

Parsimony analysis of 31 sequences of the chloroplast locus ndhF was used to address questions of subfamilial phylogeny in Bromeliaceae. Results presented here are congruent with those from chloroplast DNA restriction site analysis in recognizing a clade containing Bromelioideae and Pitcairnioideae, and in resolving Tillandsioideae near the base of the family. Placements of several taxonomically difficult genera (e.g., Glomeropitcairnia and Navia) corroborate those of traditional treatments; however, these data suggest that Brocchinia (Pitcairnioideae) is the sister group to the remainder of Bromeliaceae. Further evidence for the paraphyly of Pitcairnioideae includes the resolution of Puya as the sister group to Bromelioideae. Implications for taxonomic realignment at the subfamily level are considered.

Chloroplast DNA Analysis of Solanum bulbocastanum and S. cardiophyllum, and Evidence for the Distinctiveness of S. cardiophyllum Subsp. ehrenbergii (Sect. Petota)

Chloroplast DNA restriction site analysis was used to test hypotheses of sister group relationships of the diploid Mexican wild potato species Solanum bulbocastanum (ser. Bulbocastana) and S. cardiophyllum (ser. Pinnatisecta). A prior chloroplast DNA study including two accessions each of these two species supported them as sister taxa, widely separated from their presumed closest Mexican diploid species relatives. The present study samples more widely by examining 28 accessions of all three subspecies of S. bulbocastanum, and 20 accessions of all three subspecies of S. cardiophyllum. The results support two main clades exclusive of the outgroup: 1. Solanum bulbocastanum (all subspecies) and S. cardiophyllum (all subspecies except subsp. ehrenbergii), and 2. S. cardiophyllum subsp. ehrenbergii and members of ser. Pinnatisecta other than subsp. ehrenbergii. In the first clade, there was little resolution and some chloroplast types were shared by three subspecies of S. bulbocastanum and two subspecies of S. cardiophyllum. These results, in combination with an earlier chloroplast DNA study of the Mexican and Central American species, suggest that subsp. ehrenbergii is related to other members of ser. Pinnatisecta, possibly S. brachistotrichum or S. stenophyllidium, or alternatively that subsp. ehrenbergii obtained the chloroplast genome of a species in ser. Pinnatisecta by introgression.

Vegetative diversification and radiation in subtribeDendrobiinae (Orchidaceae): Evidence from chloroplast DNA phylogeny and anatomical characters

The data derived from a chloroplast DNA restriction site analysis of subtribeDendrobiinae (Orchidaceae) indicate that extreme vegetative diversification is concentrated in two limited parts of this group. Overlaying the vegetative character states onto the chloroplast DNA cladogram suggests that several xeromorphic, vegetative characters evolved in the lines leading to the above-mentioned clades. Several anatomical characters are also associated with xeromorphy. These vegetative and anatomical characters facilitated the establishment of this group in various dry habitats. On the other hand, the modifications of size and number of parenchymatous cells substantially contributed to the vegetative diversification. This fact implies that a simple structural adjustment can result in a major modification of growth habits in theDendrobiinae.

Dasylirion systematics: taxonomy and molecular phylogeny

The results of a systematics study in which Dasylirion was fully monographed are reported. Sixteen species, including four new ones, were recognized. Data from chloroplast DNA restriction site analysis suggest that the species of Dasylirion in southern Mexico are basal in the genus, that Nolina parviflora is particularly close to both Dasylirion and Beaucarnea , and that Calibanus is closest to Beaucarnea . The phylogeny of Dasylirion and the Agavaceae sensu lato was studied by comparison of cpDNA restriction sites and ITS rDNA sequences. The results strongly indicate that Dasylirion , Nolina , Beaucarnea , and Calibanus are a monophyletic group that is closer to Maianthemum , Polygonatum , Liriope , Dracaena and Sansevieria than to Yucca and Agave . Hosta and Camassia are at the base of the branch leading to Yucca and Agave . The molecular data indicate that Yucca hipplei is more closely related to Hesperaloe than to other species of Yucca , and that Agave dasylirioides and A. striata in the «Group Striatae» are basal to the rest of Agave . The resemblance of Aloe and Xanthorrhoea to the Agavaceae appears to be due to convergent evolution.

A Chloroplast DNA Study of the Agavaceae

A chloroplast DNA restriction site analysis of 40 taxa in the Agavaceae s.l. was undertaken to test the accuracy of several current systems of classification. In Cronquist's system, the Agavaceae contain 18 genera of fibrous-leaved, more or less woody plants such as Yucca, Hes- peraloe, Agave, Manfreda, Polianthes, Dracaena, Sansevieria, Nolina, Beaucarnea, Dasylirion, and Cordyline. In Dahlgren's system, the Agavaceae are restricted to Yucca, Hesperaloe Agave, Manfreda, Polianthes, Beschorneria, and Furcraea, while the other genera are placed in different families. These contrasting phylogenetic schemes were investigated by a chloroplast DNA restriction site analysis of these genera plus Xanthorrhoea, Hosta, Hypoxis, Hemerocallis, Asparagus, Liriope, Aspidistra, Maianthemum, and Convallaria. Phylogenetic analysis of 110 restriction site mutations, 90 of which were phylo- genetically informative, strongly supports the conclusion that there are two major lineages in this group of taxa. One well supported clade contains, sensu Dahlgren, the Nolinaceae, Dracaenaceae, and Convallariaceae. It appears that Nolina and Dasylirion are more closely related to genera such as Liriope, Maianthemum, and Dracaena than to Yucca and Agave. The other major lineage contains Yucca, Hesperaloe, Agave, Manfreda, Polianthes, Beschorneria, and Furcraea, with Hosta and perhaps Xanthorrhoea at the base. Asparagus appears to be intermediate between the two lineages. The cpDNA suggests that Cordyline, Hypoxis, and Hemerocallis are not closely related to the Agavaceae. A major problem in monocot taxonomy con- cerns the classification and phylogeny of the genera in the Liliaceae s.l. and smaller families that have been split off from it, such as the Agavaceae. Two distinct systems of classifica- tion have been proposed and both are in use at the present time (Cronquist 1981; Dahlgren et al. 1985). The apparent frequency of convergent and parallel evolution of characters in these taxa makes it difficult to recover the phylogeny us- ing morphological characters alone. In this pa- per these problems are examined using evi- dence from chloroplast DNA restriction site analysis. In the traditional taxonomic systems of Ben- tham and Hooker (1883) and Engler and Prantl (1888), most liliaceous plants with a superior ovary, including Yucca L. and Dasylirion Zucc., were placed in a broadly conceived Liliaceae with many tribes, while those with an inferior ovary, such as Agave L., were placed in the Amaryllidaceae. Hutchinson (1934) is generally

Chloroplast DNA phylogeny of Lens (Leguminosae): origin and diversity of the cultivated lentil

A restriction-site analysis of chloroplast DNA (cpDNA) variation in Lens was conducted to: (1) assess the levels of variation in Lens culinaris ssp. culinaris (the domesticated lentil), (2) identify the wild progenitor of the domesticated lentil, and (3) construct a cpDNA phylogeny of the genus. We analyzed 399 restriction sites in 114 cultivated accessions and 11 wild accessions. All but three accessions of the cultivar had identical cpDNAs. Two accessions exhibited a single shared restriction-site loss, and a small insertion was observed in the cpDNA of a third accession. We detected 19 restriction-site mutations and two length mutations among accessions of the wild taxa. Three of the four accessions of L. culinaris ssp. orientalis were identical to the cultivars at every restriction site, clearly identifying ssp. orientalis as the progenitor of the cultivated lentil. Because of its limited cpDNA diversity, we conclude that either the cultivated lentil has passed through a genetic bottleneck during domestication and lost most of its cytoplasmic variability or else was domesticated from an ancestor that was naturally depauperate in cpDNA restriction-site variation. However, because we had access to only a small number of populations of the wild taxa, the levels of variation present in ssp. orientalis can only be estimated, and the extent of such a domestication bottleneck, if applicable, cannot be evaluated. The cpDNA-based phylogeny portrays Lens as quite distinct from its putative closest relative, Vicia montbretii. L. culinaris ssp. odemensis is the sister of L. nigricans; L. culinaris is therefore paraphyletic given the current taxonomic placement of ssp. odemensis. Lens nigricans ssp. nigricans is by far the most divergent taxon of the genus, exhibiting ten autapomorphic restriction-site mutations.

Chloroplast DNA Transgresses Species Boundaries and Evolves at Variable Rates in the California Closed-Cone Pines ( Pinus radiata, P. muricata, and P. attenuata)

We studied phylogenetic relationships among populations and species in the California closed-cone pines ( Pinus radiata D. Don, P. attenuata Lemm., and P. muricata D. Don) via chloroplast DNA restriction site analysis. Data on genetic polymorphism within and among 19 populations in the three species were collected using9 to 20 restriction enzymes and 38 to 384 trees. Because only five clades and extremely low intraclade diversity were found, additional phylogenetic data were collected using a single representative per clade and two outgroup species, P. oocarpa Schiede and P. jeffreyi Loud. In total, 25 restriction enzymes were employed and approximately 2.7 kb surveyed (2.3% of genome). The five clades recognized were Monterey pine, knob-cone pine, and the southern, intermediate, and northern races of bishop pine. On the basis of bootstrapping, both Wagner and Dollo parsimony analyses strongly separated the northern and intermediate races of bishop pine from the southern race; knobcone pine from Monterey and bishop pines; and the closed-cone pines from the two outgroups. Approximate divergence times were estimated for the lineages leading to knob-cone pine and to the intermediate and northern populations of bishop pine. The position of Monterey pine relative to bishop pine within their monophyletic clade was unresolved. Surprisingly, Montery pine and the southern race of bishop pine were much more similar to one another than was the southern race of bishop pine to its conspecific intermediate and northern races. Both the Monterey and southern bishop pine lineages also evolved severalfold more slowly than did the knobcone pine and intermediate-northern bishop pine lineages. These results differ significantly from a recent allozyme study, corroborating previous observations that chloroplast genome phylogeny can depart substantially from that of nuclear genes.

CHLOROPLAST DNA EVIDENCE FOR THE INTERRELATIONSHIPS OF TOMATOES, POTATOES, AND PEPINOS (SOLANACEAE)

We used chloroplast DNA restriction site analysis to test hypotheses of relationships of Solarium subgenus Potatoe (including potatoes and pepinos), two other Solanum, Cyphomandra (the tree tomatoes), and Lycopersicon (the tomatoes). Capsicum and Datura were used as outgroups. The results support two main clades among the taxa we studied: 1) Solanum subgenus Potatoe and Lycopersicon; and 2) other Solanum and Cyphomandra. Within the first clade, the following groups were supported: a) sect. Basarthrum and sect. Anarrhichomenum; b) sect. Etuberosum; c) sect. Petota; d) sect. Juglandifolium, including subsect. Lycopersicoides; and e) the genus Lycopersicon. These results, in combination with an analysis of morphological data, advocate the controversial, but previously suggested, treatment of Lycopersicon as congeneric with Solanum in subgenus Potatoe. Thus, the cultivated tomato will be recognized as Solanum lycopersicum L. Solanum chmielewskii and Solanum lycopersicum var. cerasiforme are proposed as new combinations; Solanum neorickii is proposed as a new name for Lycopersicon parviflorum. Our data also suggest that Cyphomandra should be included within Solanum.

Chloroplast DNA Evidence for the Interrelationships of Tomtoes, Potatoes, and Pepinos (Solanaceae)

We used chloroplast DNA restriction site analysis to test hypotheses of relationships of Solarium subgenus Potatoe (including potatoes and pepinos), two other Solanum, Cyphomandra (the tree tomatoes), and Lycopersicon (the tomatoes). Capsicum and Datura were used as outgroups. The results support two main clades among the taxa we studied: 1) Solanum subgenus Potatoe and Lycopersicon; and 2) other Solanum and Cyphomandra. Within the first clade, the following groups were supported: a) sect. Basarthrum and sect. Anarrhichomenum; b) sect. Etuberosum; c) sect. Petota; d) sect. Juglandifolium, including subsect. Lycopersicoides; and e) the genus Lycopersicon. These results, in combination with an analysis of morphological data, advocate the controversial, but previously suggested, treatment of Lycopersicon as congeneric with Solanum in subgenus Potatoe. Thus, the cultivated tomato will be recognized as Solanum lycopersicum L. Solanum chmielewskii and Solanum lycopersicum var. cerasiforme are proposed as new combinations; Solanum neorickii is proposed as a new name for Lycopersicon parviflorum. Our data also suggest that Cyphomandra should be included within Solanum.

A Systematic Study of Machaeranthera (Asteraceae) and Related Groups Using Restriction Site Analysis of Chloroplast DNA

Chloroplast DNA restriction site analysis was carried out on 55 taxa of tribe Astereae, including 21 species of Machaeranthera and many additional putatively related taxa. Phylogenetic analysis delineates a well supported, monophyletic Machaeranthera alliance within Astereae that includes several segregate genera of Haplopappus and all taxa historically associated with Machaeranthera except sect. Psilactis, which is allied with Aster. The Machaeranthera alliance includes a large proportion of the taxa of tribe Astereae with x = 4, 5, and 6, and contains no taxa with base chromosome numbers greater than x = 6. Chloroplast DNA data indicate five well supported monophyletic groups within the Machaeranthera alliance. One of these groups includes Xanthocephalum, Isocoma, Prionopsis, and Grindelia (all with x = 6), but does not include the x = 6 genera Xylorhiza and Pyrrocoma. A second group includes M. sect. Sideranthus and the monotypic M. sect. Stenoloba. A third group consists of M. sect. Blepharodon and two species not normally associated with the section, M. viscida and M. gypsitherma. Comparison of cpDNA evidence with one rDNA site mutation suggests that chloroplast and nuclear genomes in M. viscida, M. gypsitherma, and M. heterophylla have different origins. A fourth group includes Pyrrocoma and M. sect. Arida. In the fifth group, cpDNA data suggest a close alliance between Oonopsis and M. sects. Machaeranthera and Hesperastrum. Molecular evidence, when considered with other data, is consistent with an hypothesis of aneuploid reduction in base chromosome number from x = 6, or ascending and descending aneuploidy from x = 5 in the Machaeranthera alliance. Machaeranthera Nees consists of mostly taprooted annual or perennial herbs that are distributed in western North America. As treated by Hartman (1976, 1990; table 1), and as here defined, the genus consists of 36 species. Except for three discoid species, all have both ray and disc florets. Ray color is variable within the genus, with both xanthic (yellow) and cyanic (white, blue, pink, purple) rays present. The composition of Machaeranthera, relationships among its sections, and its affinities to other genera have been the subject of much debate (i.e., Cronquist and Keck 1957; Hartman 1976, 1990; Shinners 1950; Turner and Horne 1964; Watson 1977). Large morphological and cytological data bases exist, but synthesis of these data with evidence from hybridization, flavonoid, and micromorphological studies has not resulted in a consensus concerning the systematics of Machaeranthera. Circumscription of Machaeranthera has been extremely difficult because the closest relatives of many species that have been placed in the genus may actually be in several different genera (i.e., Haplopappus Cass., Xylorhiza Nutt., Psilactis A. Gray, and Aster L.). The task of resolving relationships within Machaeranthera is further compounded when one considers that such taxa as Haplopappus and Aster may be even more poorly understood than Machaeranthera. Hall (1928) treated Haplopappus as a large genus of 21 sections, but most or all of the North American sections may eventually be treated as segregate genera or included in other genera. Haplopappus sect. Blepharodon is the group most commonly allied with Machaeranthera. The section has included cyanic-rayed, xanthic-rayed, and eradiate species, all of which Shinners (1950) combined with Machaeranthera. Cronquist and Keck (1957), on the other hand, included only the cyanic-rayed and eradiate species of the section in Machaeranthera (series Originales, table 2). Hartman (1976, 1990) placed the eradiate and cyanic-rayed species in Machaeranthera sect. Blepharodon and the xanthic-rayed species in Machaeranthera sects. Sideranthus, Stenoloba and Havardii (table 1). Xylorhiza has been variously treated as a section of Aster, a section of Machaeranthera, or as a distinct genus. Cronquist and Keck (1957) in-

Disassembling Papaver: a restriction site analysis of chloroplast DNA

The results from a chloroplast DNA restriction site analysis of the genera Papaver and Roemeria of subf. Papaveroideae (Papaveraceae) and five outgroup taxa are presented. Papaver is represented by 14 species of eight of the 11 sections recognized, Roemeria by two of its three species. Hunnemannia fumariifolia (subf. Eschscholzioideae), Chelidonium majus (subf. Chelidonioideae), Romneya coulteri, Argemone munita and Stylomecon heterophyllum (all subf. Papaveroideae) were chosen as outgroups. DNAs were digested with 24 restriction enzymes. The major results from this analysis are: 1. Papaver, Roemeria and Stylomecon form a monophyletic group supported by at least 17 restriction site mutations and a 150 to 300 base pair deletion in the inverted repeat of the chloroplast genome. 2. Both Stylomecon and Roemeria are nested within Papaver in its traditional circumscription. 3. Of these, Roemeria is nested within P. sect. Argemonidium and is the sister group to P. pavoninum. 4. Dependent on the mode of character weighting chosen, P. sect. Meconella either is the sister group to P. sect. Argemonidium + Roemeria or of P. sect. Argemonidium + Roemeria + Stylomecon+ the remainder of Papaver (Papaver s. str.). 5. Stylomecon is the sister group to Papaver s. str. (excluding sects Meconella and Argemonidium). These results are discussed on the background of other available systematic evidence.

Chloroplast DNA restriction site variation and phylogenetic interrelationships of some genera of the Heliantheae sensu lato (Asteraceae)

Phylogenetic interrelationships of 12 genera of the Heliantheae s. lat., as well as two genera of the Anthemideae and Eupatorieae, were assessed by chloroplast DNA restriction site analysis. The 14 investigated species represented Guizotia, Helianthus, Melampodium, Rudbeckia, Sigesbeckia, Tridax, and Verbesina (Heliantheae s. str.), Helenium, Hymenoxys, and Palafoxia (Helenieae), Porophyllum (Tageteae), Coreopsis (Coreopsideae), Pleurocoronis (Eupatorieae), and Anthemis, (Anthemideae). Using 9 enzymes, 39 phylogenetically informative sites were found. Wagner parsimony analysis of the data yielded 10 equally parsimonious cladograms. Well supported relationships displayed by all cladograms included (1) a clade comprising all the genera (Heliantheae s. lat. and Eupatorieae) except Anthemis (Anthemideae), (2) a clade consisting of the genera of the Heliantheae s. str. with Pleurocoronis (Eupatorieae) nested among them, (3) a subclade of the former comprising Pleurocoronis, Guizotia, and Sigesbeckia, and (4) the generic pair of Helenium and Hymenoxys.

Phylogeny of the Rubiaceae (Chiococceae) Based on Molecular and Morphological Data-Useful Approaches for Classification and Comparative Ecology

Phylogenies reconstructed with molecular data may provide new hypotheses of relationships. These may serve as a basis For improved morphological analyses and comparative analyses of ecological features. In this study a new phylogenetic hypothesis based on a chloroplast DNA restriction site analysis of the Rubiaceae prompted a critical analysis of morphological characters. Several unique morphological characters were identified that support a large, previously unrecognized monophyletic group, including the tribe Chiococceae. Hence, the tribe Chiococceae is amended to include members of the former Condamineeae (subtribe Portlandiinae) and the genera Exostema and Coutarea (formerly in the Cinchoneae) (...)

Relationships among native and introduced North American species of Hordeum, based on chloroplast DNA restriction-site variation

Restriction-site analysis of chloroplast DNA was carried out on a total of 13 North American species of Hordeum, 7 native and 6 introduced. Sites associated with polymorphic banding patterns were omitted so that only invariant sites within species were used in the analyses. A number of taxa whose species status is in dispute can indeed be supported at species rank, i.e., H. brachyantherum, H. californicum, H. pusillum, H. intercedens, H. marinum, and H. geniculatum. The maternal progenitor of H. arizonicum is H. pusillum, and this is further discussed in light of other possibilities. Both phenetic and cladistic analyses indicate a tripartite relationship whereby H. vulgare is distant from the group of H. leporinum, H. glaucum, and H. murinum and from a second group comprising the native species H. brachyantherum, H. californicum, H. arizonicum, H. jubatum, H. pusillum, H. intercedens, and H. depressum. Hordeum marinum and H. geniculatum occupy a central position in this relationship. Speculation that the putative ancient form of Hordeum resembled a H. murinum – H. geniculatum-like species is discussed. Key words: chloroplast DNA, Hordeum, phylogenetic relationships.