Topic
Antennaria
About: Antennaria is a research topic. Over the lifetime, 43 publications have been published within this topic receiving 543 citations. The topic is also known as: everlasting.
Papers
TL;DR: An electrophoretic study was initiated to assess the degree of divergence among the five diploid species and to test the hypotheses of the hybrid (allopolyploid) origins of A. parlinii and A. neodioica.
Abstract: The Antennaria parlinii and A. neodioica agamic complexes are widely distributed across North America. Morphological data have suggested that these dioecious, perennial, entireleaved herbs are of multiple hybrid origin from among five sexual diploid species. Antennaria neglecta, A. plantaginifolia, A. racemosa, and A. virginica are hypothesized to be the diploid progenitors of the A. neodioica complex, whereas A. parlinii sensu lato is thought to include the genomes of A. plantaginifolia, A. racemosa, and A. solitaria. An electrophoretic study was initiated to assess the degree of divergence among the five diploid species and to test the hypotheses of the hybrid (allopolyploid) origins of A. parlinii and A. neodioica. Twenty genetic loci were surveyed in 76 populations of the diploid and polyploid taxa. The diploid species are well defined morphologically, although the genetic basis of differences distinguishing them have not been determined. The species exhibit little divergence at genes specifying soluble enzymes, however each species has unique alleles in highest frequency at one or two genes. Allozymes indicate that gene diversity in the obligately outcrossing diploids occurs primarily within rather than among populations. The shale barren endemic, A. virginica, is as genetically diverse as the more edaphically diverse and widespread species. Tetraploid cytotypes of diploid (2n = 28) A. virginica possess the same allozymes as the diploids and these cytotypes appear to be of autopolyploid (non-hybrid) origin. Enzyme electrophoresis is concordant with morphological data in suggesting that A. neodioica contains the genomes ofA. neglecta, A. virginica, A. plantaginifolia, A. racemosa and perhaps A. solitaria whereas the latter three species are the progenitors of A. parlinii.
69 citations
TL;DR: The current study presents 137 new chromosome determinations for Antennaria from throughout North America, including previously unreported species include A. marginata, A. ro- sulata, and A. stenophylla.
Abstract: The current study presents 137 new chromosome determinations for Antennaria from throughout North America. Previously unreported species include A. atriceps, A. marginata, A. ro- sulata, and A. stenophylla. Although a few taxa remain uncounted, a reasonable summary of the chromosomal diversity for the entire genus can be made. Three groups of taxa are recognized based primarily on ploidy level and reproductive mode. One assemblage of taxa (group 1) is always sexual, primarily diploid, and is unrelated to the polyploid agamic complexes of group 3. Another category (group 2) consists of species that occur as diploids or tetraploids and are the probable diploid progenitors of the polyploids. The sexual diploid taxa are distinct morphologically and generally occur in southern latitudes and unglaciated regions. The polyploids (group 3) are frequently widely distributed in both southern latitudes and northern glaciated ones and are morphologically diverse. Antennaria Gaertner is distributed primarily in temperate to arctic regions of the northern hemisphere and has centers of diversity in western North America that indicate it proba- bly originated in the Rocky Mountains. Poly- ploidy, extensive hybridization, apomixis, and dioecy are all prevalent in Antennaria and have contributed to its well-known taxonomic com- plexity. Documentation of the occurrence, dis- tribution, and association of these processes can provide an explanation for the taxonomic com- plexities within Antennaria. Conversely, a full knowledge of the biosystematics of Antennaria will undoubtedly add much to an understand- ing of the evolutionary significance of these processes. The current paper, which reviews the distribution of cytotypes in the genus, is a step in that direction.
62 citations
TL;DR: A cladistic analysis of a morphological data set supports the monophyly of the genus and the recognition of two previously established subgenera and a discussion of species relationships and historical biogeography is presented as suggested by morphological parsimony analysis.
Abstract: A revision of the dioecious genus Chersodoma (Senecioneae, Asteraceae) recognizes nine species, including a new species, C. deltoidea Sagast. & M. O. Dillon, from northern Peru and a status change for a northwestern Argentine endemic, C. glabriuscula (Cabrera) M. O. Dillon & Sagast. Chersodoma is confined to the Andean Cordillera and is the only dioecious member of the Senecioneae in continental South America. A cladistic analysis of a morphological data set supports the monophyly of the genus and the recognition of two previously established subgenera. Subgenus Chersodoma contains three species (C. argentina, C. candida, C. jodopappa) with greatest diversity in the semi-arid puna of northwestern Argentina and adjacent Bolivia and Chile. Subgenus Diclinanthus B. Nord., contains six species (C. antennaria, C. arequipensis, C. deltoidea, C. juanisernii, C. glabriuscula, and C. ovopedata) with greatest diversity in Peru. A key to Andean genera of Senecioneae is provided. A discussion of species relationships and historical biogeography is presented as suggested by morphological parsimony analysis.
61 citations
TL;DR: The distribution of chromosome numbers in eastern United States Antennaria demonstrates that two diploids and many polyploids occur above the glacial margin, and thus there is an increase in the frequency of polyploidy with latitude.
Abstract: Chromosome numbers are presented for 99 populations of 13 species of Antennaria, including A. plantaginifolia, A. neglecta, A. virginica, A. solitaria, A. racemosa, A. corymbosa, A. rosea, A. media, A. Parlinii, A. fallax, A. neodioica, A. canadensis, and A. petaloidea. Four species from the eastern United States (A. plantaginifolia, A. neglecta, A. solitaria, and A. virginica) were determined as diploid (n = 14), and these are all sexual. Diploid counts were also obtained for two sexual species (A. racemosa and A. corymbosa) from the western United States. Chromosome counts are presented for two heteroploid agamic complexes occurring in the eastern United States; these include what have traditionally been referred to as A. Parlinii, A. fallax, A. neodioica, A. canadensis, and A. petaloidea. Determinations of 2n = 56, 70, 84, and 112 were obtained for the A. Parlinii and A. fallax groups, where 2n = 84 had been the only number previously reported. Numbers of 2n = 84 were confirmed for A. petaloidea and A. canadensis and 2n = 56 for A. neodioica. The western United States polyploid species (A. rosea and A. media) are reported as 2n = 56. The presence of apomixis is correlated with polyploidy. The distribution of chromosome numbers in eastern United States Antennaria demonstrates that two diploids and many polyploids occur above the glacial margin, and thus there is an increase in the frequency of polyploidy with latitude. Colonization of the glaciated region by Antennaria following the recession of the Wisconsin ice sheet is also discussed. Many of the polyploids occur only in the glaciated region, thus suggesting a recent origin for these cytotypes. There is evidence indicating that the original base number in Antennaria may be
31 citations
1 Jan 1987
28 citations
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2019 | 1 |
| 2015 | 1 |
| 2010 | 1 |
| 2006 | 1 |
| 2005 | 1 |