| 1. |
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| 2. |
- Bella, Eleni, et al.
(författare)
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Genetic insights into the hybrid origin of Abies x borisii-regis Mattf.
- 2015
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 0378-2697 .- 1615-6110 .- 2199-6881. ; 301:2, s. 749-759
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Tidskriftsartikel (refereegranskat)abstract
- Abies × borisii-regis Mattf. (King Boris fir) is a taxon endemic to the southern Balkan Peninsula, described as a hybrid between the widespread A. alba Mill. (Silver fir) and the Greek endemic A. cephalonica Loud (Greek fir). Even though A. × borisii-regis has attracted much research attention in the past, its origin, geographical distribution and taxonomic status are not fully elucidated and molecular evidence for hybridization is missing. To shed more light on this issue, we analyzed representative populations from these three Abies taxa using paternally inherited (chloroplast) and maternally inherited (mitochondrial) DNA markers. Both Silver and Greek fir could be clearly distinguished using mitochondrial markers, while we observed a mixture of maternal lineages in theA. × borisii-regis populations. In contrast, using chloroplast markers, we could not identify species-specific haplotypes, but a neighbor-joining analysis of population genetic distances revealed two separate clusters for the Silver fir and the Greek fir, while the A. × borisii-regis populations were placed in intermediate positions. Our results are in agreement with the hypothesis that the A. ×borisii-regis populations investigated are a result of hybridization between A. cephalonica and A. alba.
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| 3. |
- Bengtson, Annika, et al.
(författare)
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Species diversification in the Mediterranean genus Chiliadenus (Inuleae-Asteraceae)
- 2018
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 0378-2697 .- 1615-6110 .- 2199-6881. ; 304:7, s. 853-860
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Tidskriftsartikel (refereegranskat)abstract
- Chiliadenus is a small genus in the Inuleae (Asteraceae), consisting of ten species with allopatric distributions along the southern edge of the Mediterranean Sea. The different species have restricted areas of distribution, with only one being more widely distributed. The first molecular phylogenetic study of the genus with complete sampling, as well as a biogeographic analysis of the origin and biogeographic patterns leading to the current diversity of Chiliadenus is presented. Results confirm Chiliadenus as monophyletic and placed as sister to Dittrichia. The ancestor of Chiliadenus is dated to have diverged from that of Dittrichia around 5.45 Ma ago, coinciding with the Messinian salinity crisis, whereas the Chiliadenus crown group is dated to 2.29 Ma, around 3 million years later. Ancestral area reconstructions show the crown group to likely have originated in the area around Morocco and northwestern Algeria, which is also the area where the early divergences have occurred. Chiliadenus has then later diverged and dispersed over the Mediterranean to its current distribution. The evolution of the Chiliadenus crown group coincides with the onset of the Mediterranean climate, and its evolution may be connected to the subsequent climatic changes.
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| 4. |
- Blackmore, Stephen, et al.
(författare)
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Developmental origins of structural diversity in pollen walls of Compositae
- 2010
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 0378-2697 .- 1615-6110. ; 284:02-jan, s. 17-32
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Tidskriftsartikel (refereegranskat)abstract
- Compositae exhibit some of the most complex and diverse pollen grains in flowering plants. This paper reviews the evolutionary and developmental origins of this diversity in pollen structure using recent models based on the behaviour of colloids and formation of micelles in the differentiating microspore glycocalyx and primexine. The developmental model is consistent with observations of structures recovered by pollen wall dissolution. Pollen wall diversity in Compositae is inferred to result from small changes in the glycocalyx, for example ionic concentration, which trigger the self-assembly of highly diverse structures. Whilst the fine details of exine substructure are, therefore, not under direct genetic control, it is likely that genes establish differences in the glycocalyx which define the conditions for self-assembly. Because the processes described here for Compositae can account for some of the most complex exine structures known, it is likely that they also operate in pollen walls with much simpler organisation.
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| 5. |
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| 6. |
- Bremer, B, et al.
(författare)
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Phylogeny and classification of the subfamily Rubioideae (Rubiaceae)
- 2000
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Ingår i: PLANT SYSTEMATICS AND EVOLUTION. - : SPRINGER-VERLAG WIEN. - 0378-2697. ; 225:1-4, s. 43-72
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Tidskriftsartikel (refereegranskat)abstract
- We performed phylogenetic analyses of the subfamily Rubioideae (Rubiaceae) based on three different pieces of chloroplast DNA, the protein coding rbcL gene, the spacer sequence between atpB and rbcL (atpB-rbcL), and the recently published (Andersson and R
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| 7. |
- Cronberg, Nils, et al.
(författare)
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Hybridization between the peat mosses, Sphagnum capillifolium and S. quinquefarium (Sphagnaceae, Bryophyta) as inferred by morphological characters and isozyme markers
- 2002
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 1615-6110 .- 0378-2697. ; 234:1-4, s. 53-70
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Tidskriftsartikel (refereegranskat)abstract
- Isozyme markers and morphological characters were studied in four populations of Sphagnum capillifolium and S. quinquefarium. Recombinant plants were found in three populations, where the two species occur sympatrically. All recombinants possessed different haplotypes and combinations of morphological characters, which show that they are results of independent hybridization events. Strongly male-biased sex ratios were found for Sphagnum capillifolium in all populations where it grew sympatrically with S. quinquefarium. Most of the recombinants were also male fertile. These observations suggest that S. quinquefarium is the female parent in the primary crosses and in subsequent backcrosses.
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| 8. |
- Dawes, T., et al.
(författare)
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Extremely low genetic diversity in the European clade of the modelbryophyte Anthoceros agrestis
- 2020
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 0378-2697 .- 1615-6110 .- 2199-6881. ; 306:2
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Tidskriftsartikel (refereegranskat)abstract
- The hornwort Anthoceros agrestis is emerging as a model system for the study of symbiotic interactions and carbon fixation processes. It is an annual species with a remarkably small and compact genome. Single accessions of the plant have been shown to be related to the cosmopolitan perennial hornwort Anthoceros punctatus. We provide the first detailed insight into the evolutionary history of the two species. Due to the rather conserved nature of organellar loci, we sequenced multiple accessions in the Anthoceros agrestis–A. punctatus complex using three nuclear regions: the ribosomal spacer ITS2, and exon and intron regions from the single-copy coding genes rbcS and phytochrome. We used phylogenetic and dating analyses to uncover the relationships between these two taxa. Our analyses resolve a lineage of genetically near-uniform European A. agrestis accessions and two non-European A. agrestis lineages. In addition, the cosmopolitan species Anthoceros punctatus forms two lineages, one of mostly European accessions, and another from India. All studied European A. agrestis accessions have a single origin, radiated relatively recently (less than 1 million years ago), and are currently strictly associated with agroecosystem habitats.
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| 9. |
- Dida, Mulatu Geleta, et al.
(författare)
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Phylogenetics and taxonomic delimitation of the genus Guizotia (Asteraceae) based on sequences derived from various chloroplast DNA regions
- 2010
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 0378-2697 .- 1615-6110. ; 289, s. 77-89
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Tidskriftsartikel (refereegranskat)abstract
- Parsimony-based phylogenetic analyses of the genus Guizotia were undertaken based on DNA sequence data from the following chloroplast DNA (cpDNA) regions: trnT-trnL, trnL-trnF, trnY-rpoB, trnC-petN, psbM-trnD and rps16-trnQ intergenic spacers, trnL, rps16 and matK-5'trnK introns and matK gene. Out of the 26 primers used in this study, 14 were newly designed. The study was conducted to determine (1) the closest relative of Guizotia abyssinica, (2) the taxonomic status of some Guizotia taxa and (3) the subtribal placement of Guizotia in the tribe Heliantheae. The analyses of the sequence data showed that G. abyssinica, G. scabra ssp. scabra, G. scabra ssp. schimperi and G. villosa are phylogenetically closely related. However, G. scabra ssp. schimperi appeared as the most closely related taxon to G. abyssinica. Based on this phylogenetic analysis, we suggest that the two subspecies of G. scabra are better treated as separate species. The analysis also clearly demonstrated that "Chelelu" and "Ketcha" are distinct Guizotia species. The trnT-trnL and trnL-trnF intergenic spacer-based phylogenetic analysis of various subtribes of the tribe Heliantheae strongly supports the placement of the genus Guizotia within the subtribe Milleriinae.
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| 10. |
- Ehlers, B. K., et al.
(författare)
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Floral morphology and reproductive success in the orchid Epipactis helleborine : regional and local across-habitat variation
- 2002
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 0378-2697 .- 1615-6110. ; 236:1-2, s. 19-32
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Tidskriftsartikel (refereegranskat)abstract
- The terrestrial orchid Epipactis helleborine is a morphologically variable species with a wide distribution in Europe. It is pollinated by social wasps, and most populations show the morphological characteristics of outcrossing species. However, local predominantly selfing subspecies and varieties have been documented from drier habitats. To document geographic variation in floral morphology, ability to produce seeds through autogamy, and reproductive success in E. helleborine, we sampled 13 populations from three geographic regions along a latitudinal gradient of c. 1000 km from northern to southern Sweden. In the southernmost region, populations in dry and mesic habitats were compared. Supplemental hand-pollination was conducted to determine whether among-population variation in fruit set could be explained by differences in the natural level of pollination, and whether any relationship between floral morphology and fruit production could be explained by interactions with pollinators. Bagging experiments showed no evidence of autogamy in any of the study populations. Number of flowers, pollinia removal and fruit set varied significantly among populations but did not differ among regions. Pollinia removal was positively correlated with population size and both pollinia removal and fruit set were lower in dry than in mesic habitats. At the level of the individual plant, the number of pollinia removed increased more rapidly with flower number than did number of fruits produced. The hand-pollination experiment indicated that the positive relationship between number of flowers and fruit production was due to a higher degree of pollen limitation in plants with few flowers than in plants with many flowers. The experiment also showed that variation in the level of pollen limitation could only partly explain variation in fruit set among populations.
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