Content uploaded by Jaanus Paal
Author content
All content in this area was uploaded by Jaanus Paal on Sep 24, 2014
Content may be subject to copyright.
Potentilla L. sect. Rivales Wolf and related taxa in the Baltic states
Abstract
Morphological variation ofPotentilla norvegica L.,P. heidenreichii
Zimmeter andP. supina L. usually treated within the sectionRivales
Wolf,P. recta L. (sect.Rectae
Wolf),P. canescens
Bess.,P. argentea L. s.l.,P. collina
Wibel (sect.Argenteae
Wolf) andP. goldbachii
Rupr. (sect.Chrysanthae
Wolf) was studied using multivariate statistical methods. According to k-means clustering,P. canescens stands closer toP. heidenreichii of the sect.Rivales than toP. argentea. P. collina, the other representative of sect.Argenteae, is not connected withP. canescens at all. Therefore,P. canescens should belong to sect.Rivales and not to sect.Argenteae.
InPotentilla argentea s.l.,P. impolita
Wahlenb.,P. argentea L. var.argentea, var.decumbens (Jord.)Lehm., var.demissa
(Jord.) Lehm., var.grandiceps
(Zimmeter) Rouy etE.G. Camus and var.tenerrima
(Velen.) Wolf were identified.P. impolita specimens did not cluster out into a separate cluster as didP. collina, P. canescens andP. heidenreichii, but formed mixed clusters with different varieties ofP. argentea s.str. Therefore,P. impolita is not worthy of the rank of species and evidently not even that of subspecies, and should be treated as a variety—P. argentea var.incanescens
(Opiz) Focke.
Chromosome numbers in 80 populations belonging to 18 species of Potentilla L. subgen.Potentilla from the Iberian Peninsula and two of P. maura, a North African endemic taxon, have been counted. The basic number of chromosomes is always x=7 and these chromosomes are small (between 1 and 2 μm). For three species, the number of chromosomes is reported for the first time and, for another six, this number has been established in Iberian representatives. Moreover, new ploidy levels have been obtained for P. hispanica and P. crantzii with regard to their entire distribution area, and in P. cinerea and P. neumanniana for the Iberian Peninsula. Some taxonomic, phylogenetic and phytogeographic comments are made for several species or groups of species from the West Mediterranean region. In 13 species only one ploidy level has been found, but six species have several ploidy levels. Seven ploidy levels occur in the investigated taxa. The frequency of each ploidy level represented within Iberian Potentilla is analysed and the data are compared with those available for taxa from the rest of the distribution area of the genus.
A multivariate analysis has been performed in order to study the polymorphisms of the three species ofPotentilla sect.Recta (Th. Wolf)Juzepchuk represented in the Iberian Peninsula:P. asturica
Rothm.,P. hirta L. andP. recta L. The variability of 20 characters (quantitative, binary and qualitative) has been evaluated in 76 collections mostly from
the Iberian Peninsula and from other European territories, but also from North America, and North Africa. The analyses performed
provide support for the recognition of the three species. The most discriminant among the quantitative characters is the width
of the long trichomes on the stem, and then the width of the long trichomes on the leaves and the maximum length of the long
trichomes. The interval of number of carpels, presence or absence of short eglandular trichomes and the abundance of long
eglandular trichomes (>3 mm) are the most discriminant ones among the qualitative ones. The taxonomical position ofP. asturica, which has been previously subordinated as a subspecies within the other two taxa, is discussed. Our results support a good
delimitation of this taxon which, on the basis of the morphological characters studied by us, seems to be morphologically
more close toP. hirta than toP. recta, but differs significantly from both. A key to the three species is provided.
180 specimens of P. erecta, 58 of P. reptans, 49 of P. anglica and 19 of P. x italica were studied phenetically using 19 macromorphological characters. As P. erecta and P. reptans are quite common in Estonia, while P. anglica is absent from here, the occurrence of P. x italica in Estonia points to its possible origin from the hybridization of the former two species. Estonian P. x italica produces no seeds and is hexaploid (2n=42). P. x italica and P. anglica appeared, from the statistical point of view, morphologically well separable from each other as well as from their putative parents. In comparison with the varieties of P. erecta, var. erecta and var. strictissima, which do not cluster into separate groups, it is reasonable to deal with P. x italica, which clearly forms clusters of its own, on the same level as P. reptans and P. anglica, i. e. to treat it as a morphologically stable nothospecies.
The presented molecular and cytological study of the European Potentilla argentea group (Rosaceae) demonstrates the importance of ploidy differentiation for the evolutionary diversification in apomictic plants. Despite the frequent occurrence of cytologically-polymorphic populations in apomicts, few studies have addressed the evolutionary relationships among cytotypes and their taxonomic implications. Combined analyses of amplified fragment length polymorphisms (AFLPs), chloroplast DNA sequences, and ploidy have identified three main evolutionary lineages within the Potentilla argentea group. The molecular data unravelled a clear separation of European P. argentea s.l. into a diploid and a hexaploid lineage, as well as a Southern European diploid P. calabra. Potentilla argentea var. pseudocalabra was intermediate between hexaploid P. argentea and P. calabra. Diploid and hexaploid P. argentea occur separately in Western and Eastern Europe, respectively, but are found in sympatry in Central and Northern Europe. Population genetic patterns and character incompatibility tests suggested that hexaploids were apomictic, while diploid P. argentea and P. calabra were selfers and outcrossers, respectively. The data strongly support the consideration of all three taxa as separate species and an allopolyploid origin for the hexaploid P. argentea. Furthermore, the results are concordant with the strong correlation between polyploidy and apomixis in other species, and provide a model system for studying the origin of apomixis involving autogamous diploids.
Chromosome numbers in 80 populations belonging to 18 species of Potentilla L. subgen. Potentilla from the Iberian Peninsula and two of P. maura, a North African endemic taxon, have been counted. The basic number of chromosomes is always x = 7 and these chromosomes are small (between 1 and 2 μm). For three species, the number of chromosomes is reported for the first time and, for another six, this number has been established in Iberian representatives. Moreover, new ploidy levels have been obtained for P. hispanica and P. crantzii with regard to their entire distribution area, and in P. cinerea and P. neumanniana for the Iberian Peninsula. Some taxonomic, phylogenetic and phytogeographic comments are made for several species or groups of species from the West Mediterranean region. In 13 species only one ploidy level has been found, but six species have several ploidy levels. Seven ploidy levels occur in the investigated taxa. The frequency of each ploidy level represented within Iberian Potentilla is analysed and the data are compared with those available for taxa from the rest of the distribution area of the genus.
Several naturally occurring hybrids in Potentilla (Rosaceae) have been reported, but no molecular evidence has so far been available to test these hypotheses of hybridization. We have compared a nuclear and a chloroplast gene tree to identify topological incongruences that may indicate hybridization events in the genus. Furthermore, the monophyly and phylogenetic position of the proposed segregated genera Argentina, Ivesia and Horkelia have been tested. The systematic signal from the two morphological characters, style- and anther shape, has also been investigated by ancestral state reconstruction, to elucidate how well these characters concur with the results of the molecular phylogenies.
Six major clades, Anserina, Alba, Fragarioides, Reptans, ivesioid and Argentea, have been identified within genus Potentilla. Horkelia, Ivesia and Horkeliella (the ivesioid clade), form a monophyletic group nested within Potentilla. Furthermore, the origin of the proposed segregated genus Argentina (the Anserina clade) is uncertain but not in conflict with a new generic status of the group. We also found style morphology to be an informative character that reflects the phylogenetic relationships within Potentilla. Five well-supported incongruences were found between the nuclear and the chloroplast phylogenies, and three of these involved polyploid taxa. However, further investigations, using low copy molecular markers, are required to infer the phylogeny of these species and to test the hypothesis of hybrid origin.
On the Karula Upland, South Estonia, the forest moss layer was analysed using a transect of 726 contiguous 0.2×0.2 m plots.
The sample plots were classified according to a multistage clustering procedure based on the sequential use of algorithms
with different criteria. Several obtained clusters are rather similar in species composition, but abundance relationships
among dominant species are distinctly different. For detailed analysis of mutual relations among societies a formal definition
of adjacency is proposed, and two aspects of the cluster continuum — transitionality and distinctness — are estimated. It
appears that almost all resulting societies are very distinct (P<0.05), but at the same time can be continual in the sense of transitionality. Spatial changes in vegetation along transects
are also discontinuous. The null hypothesis assuming the independency of neighbouring sample plots type was refuted withP=0.01. The spatial extent of different synusiae is typically several times larger than it should be if there were no structure
in moss vegetation.
A regressive bulk carmine staining schedule was adapted from a formula proposed by P. Mayer. The stain is made by boiling gently 4 gm of certified carmine in 15 ml of distilled water to which 1 ml of concentrated HC1 has been added. After cooling, 95 ml of 85% alcohol is added, and the solution filtered. Fixed tissue is soaked in the stain until thoroughly penetrated; squashes are then prepared as usual, but plain 45% acetic acid is used as the temporary mounting medium instead of aceto-carmine. The advantages of this method are: intense, precise staining of chromosomes coupled with a lightly stained cytoplasm; consistency and uniformity of results; simplicity of use.
Chromosome numbers of flowering plants Sexuality, apomixis and polyploidy: Potentilla argentea as a critical example Catalogusflorae austriae
- Mir
- Moscow
- J M Edmonds
Mir, Moscow. EDMONDS J. M. (1982): Epidermal hair morphology in Solanum L. section Solanum. Bot. J. Linn. Soc. 85: 153-167. EICHWALD K. (1962): Potentilla L. In: E1CHWALD K. et al. (eds.), Eesti NSVfloora 2, Eesti Riiklik Kirjastus, Tallinn, pp. 320-348. FEDOROV A. (ed.) (1969): Chromosome numbers of flowering plants, Nauka, Leningrad. GARCKE A. (1972): lllustrierte Flora von Deutschland und angrenzende Gebiete. Verlag Paul Parey, Berlin, Hamburg. HOLM S. (1996): Sexuality, apomixis and polyploidy: Potentilla argentea as a critical example. Dept. Genetics, Lund University, Lund. JANCHEN E. (1957): Catalogusflorae austriae. Springer Verlag, Wien. JUZEPCHUK S. (1941): Potentilla L. In: KOMAROV V. (ed.), Flora URSS 10, Editio Academiae Scientarum URSS, Moscow, Leningrad, pp. 68-223. LEHT M. ( 1987): The genus Potentilla L. in the Baltic republics in connection with some taxonomical problems.
Some new results concerning apomixis, sexuality and polymorphism in Potentilla Taxonomic continuum, some problems and methods for its quantitative analysis The plant cover of the Estonian SSR; Flora, vegetation and ecology
- Leht M Egl 'i 'te Z
- M Lapeli~
- Norsk
- Flora
- Det
- Samlagel
- Oslo
- J Lid
- D J Lid
LEHT M., EGL'I'TE Z. & LAPELI~ M. (1996): Potentilla L. In: KUUSK V., TABAKA L. & JANKEVICIENE R. (eds.), Flora of the Baltic countries, Compendium of vascular plants 2, Eesti Loodusfoto, Tartu, pp. 68-79. LID J. (1987): Norsk, svensk, finsh Flora. Det Norske Samlagel, Oslo. LID J. & LID D.J. (1994): Norsk Flora. Det Norske Sarnlagel, Oslo. MON'I~NG A. & MONTZING G. (1941): Some new results concerning apomixis, sexuality and polymorphism in Potentilla. Bot. Not. 94: 237-278. PAAL J. (1987): Taxonomic continuum, some problems and methods for its quantitative analysis. In: LAASIMER L. & KULL T. (eds.), The plant cover of the Estonian SSR; Flora, vegetation and ecology, Valgus, Tallinn, pp. 108-122. PAAL J. (1994): Moss synusiae in South Estonian forests. Folia Geobot. Phytotax. 29: 497-509.