Cytogeography and taxonomy of the Paeonia obovata polyploid complex (Paeoniaceae)

 The taxonomy of the Paeonia obovata polyploid complex in E-Asia has been controversial with treatments ranging from one species and two varieties to five species and numerous infraspecific taxa. Extensive observations in the field, analysis of morphological characters based on 32 populations sampled, and the examination of a large amount of herbarium specimens show that all the characters used by previous authors for distinguishing the species are variable between or even within populations: Leaf position, petal colour, stamen number (from 21 to 110 in the red-flowered and from 58 to 239 in the white-flowered form), filament and anther colour, style length as well as follicle number and position. Therefore, all these characters are of no value for species delimitation. However, an extensive chromosome survey and the analysis of morphological characters show that the ploidy level is basically correlated with the geographical distribution and with the indumentum on the lower leaf surface. Thus, the recognition of one species with two subspecies is proposed: Paeonia obovata subsp. obovata, mostly diploid, widely distributed in the north, east and south of the distribution range and glabrous to sparsely pubescent or hirsute on the lower leaf surface, and subsp. willmottiae, tetraploid, limited to the west and with leaves densely hirsute or pubescent below. Received October 30, 1998 Accepted June 21, 2000     

A Morphometric Study of Populations of the Centaurea jacea Complex (Asteraceae) in Belgium

Abstract: The Centaurea jacea aggregate is a polymorphic polyploid complex whose taxonomic treatment is still controversial. A numerical taxonomic approach was applied to 394 individuals of known ploidy level, from 19 populations, based on the main diagnostic characters proposed in earlier revisions. Populations from xeric grasslands were not considered. Principal Component Analysis shows that variation within the complex is continuous. UPGMA Cluster Analysis based on population means supports the recognition of three groups of populations. However, the limits between these groups are blurred to a considerable extent due to extensive within-population polymorphism. It is argued that the Belgian populations of Centaurea jacea occurring in mesic grasslands should be treated as a single species, with three subspecies. The two extremes of the morphological gradient can be referred to as C. jacea subsp. jacea and C. jacea subsp. nigra, with C. jacea subsp. pratensis occupying an intermediate position. Most populations from Belgium are tetraploid, a diploid chromosome number being found only in populations of C. jacea subsp. nigra from the Ardennes massif. On average, diploids grow at higher altitude and on more acidic soils than tetraploids. Finally, a key to the three subspecies is provided.     

Polyploidy in the olive complex (Olea europaea): evidence from flow cytometry and nuclear microsatellite analyses

BACKGROUND: Phylogenetic and phylogeographic investigations have been previously performed to study the evolution of the olive tree complex (Olea europaea). A particularly high genomic diversity has been found in north-west Africa. However, to date no exhaustive study has been addressed to infer putative polyploidization events and their evolutionary significance in the diversification of the olive tree and its relatives. METHODS: Representatives of the six olive subspecies were investigated using (a) flow cytometry to estimate genome content, and (b) six highly variable nuclear microsatellites to assess the presence of multiple alleles at co-dominant loci. In addition, nine individuals from a controlled cross between two individuals of O. europaea subsp. maroccana were characterized with microsatellites to check for chromosome inheritance. KEY RESULTS: Based on flow cytometry and genetic analyses, strong evidence for polyploidy was obtained in subspp. cerasiformis (tetraploid) and maroccana (hexaploid), whereas the other subspecies appeared to be diploids. Agreement between flow cytometry and genetic analyses gives an alternative approach to chromosome counting to determine ploidy level of trees. Lastly, abnormalities in chromosomes inheritance leading to aneuploid formation were revealed using microsatellite analyses in the offspring from the controlled cross in subsp. maroccana. CONCLUSIONS: This study constitutes the first report for multiple polyploidy in olive tree relatives. Formation of tetraploids and hexaploids may have played a major role in the diversification of the olive complex in north-west Africa. The fact that polyploidy is found in narrow endemic subspecies from Madeira (subsp. cerasiformis) and the Agadir Mountains (subsp. maroccana) suggests that polyploidization has been favoured to overcome inbreeding depression. Lastly, based on previous phylogenetic analyses, we hypothesize that subsp. cerasiformis resulted from hybridization between ancestors of subspp. guanchica and europaea.     

On a new subspecies of Adoxa moschatellina (Adoxaceae), apoendemic in Calabria (S Italy)

Adoxa moschatellina subsp. cescae subsp. nova is proposed. Phytogeographical, karyological and morphological evidences are presented. This subspecies appear to be endemic to the Coastal Chain, Calabria (S Italy) and shows a triploid (2n = 54) chromosome complement, different from the diploid (2n = 36) one of A. moschatellina s.s. By a morphological point of view, pollen and stomata size of the latter (from the whole Italy, including the Pollino Massif, N Calabria) appear to be smaller in average than those of the new subspecies, which can be considered as a new apoendemic taxon, because of its distribution and high ploidy level.     

Chromosome numbers and geographical distribution of Ulex europaeus subsp. europaeus (Leguminosae)

FERNANDEZ PRIETO, J. A., VERA, M. L., ALVAREZ MARTINEZ, M. J., DIAZ, T. E., FERNANDEZ CASADO, M. A., FERNANDEZ-CARVAJAL, M. C, GUTIERREZ VILLARIAS, M. I. & NAVA, H. S., 1993. Chromosome numbers and geographical distribution of Ulex europaeus subsp. europaeus (Leguminosae). Chromosome numbers are reported in Ulex europaeus subsp. europaeus (99 samples from northern Spain, France and Great Britain). Three levels of ploidy (diploid, tetraploid and hexaploid) have been detected; the diploid and tetraploid levels, hitherto unknown in this taxon, have been found exclusively in coastal areas of northern Spain and western France.     

Novelties in the Festuca valesiaca group (Poaceae) from the central Alps

Due to their ploidy levels, their morphological and anatomical characters and their distribution the central alpine Festuca stricta subsp. bauzanina (2n = 8x = 56) and Festuca ovina var. guinochetii (2n = 10x = 70), both belonging to the Festuca valesiaca group, are raised to the specific level. As a new subspecies Festuca bauzanina subsp. rhaetica is described here. The taxa of the polyploid Festuca valesiaca group are morphologically, anatomically and chorologically characterised and an identification key for these taxa in the central Alps is presented.     

Karyological and taxonomic notes on Genista L. (Papilionoideae, Leguminosae) from the Iberian Peninsula

Karyological information about Iberian Genista species is limited because of their wide geographical distribution. It is a major factor in the understanding of a genus whose genetic evolution is mostly related to aneuploidy and euploidy. The chromosome numbers of the following taxa have been counted: G. carpetana subsp. carpetana (n = 20), G. cinerascens (n = 12), G. micrantha (n = 18), G. mugronensis subsp. rigidissima (n = 18), G. ramosissima (2n = 48) and G. tinctoria (n = 24). The previously-assumed uniformity of chromosome number (n = 24) for all the subspecies of G. cinerea is supported here by data from subspp. murcica and speciosa. In G. florida, a new chromosome number, n = 23, has been found for both subspecies (florida and polygaliphylla). A discussion of the discrepancies between these data and previous ones is included. A new level of ploidy has been found in G. tuurnefortii subsp. tournefortii (n = 32). The data stress the necessity of obtaining chromosomal information from a number of plants of a taxon before its characteristic number is clear, and indicate that more chromosomal data will help the understanding of the cytological diversity within taxa in Genista.     

Karyotype morphology and cytogeography in Brunnera and Cynoglottis (Boraginaceae)

A comparative study of karyotype morphology and heterochromatin patterns in Brunnera and Cynoglottis (Boraginaceae) was carried out with traditional methods and Giemsa C-banding. Two polymorphic species of Cynoglottis , each with two subspecies, and two of Brunnera were investigated using native population samples from the central-eastern Mediterranean and Middle East. Pollen size of these samples was measured to investigate relationships with ploidy level. C. barrelieri subsp. barrelieri and subsp. serpentinicola are characterized by In = 18 and smaller pollen grains in contrast to C. chetikiana subsp. chetikiana and subsp. paphlagonica , which are fundamentally tetraploid with 2n = 36. The occurrence of cytotypes with 2n –/2 and 2n = 24 in both subspecies of C. chetikiana , however, would suggest x = 6 as the original haploid number and x = 9 as a derived one. Furthermore, the finding of a hypoploid cytotype with 2n = 16 in C. barrelieri ssp. barrelieri was consistent with previous reports and suggested relationships with Anchusa. Karyoevolutionary processes possibly associated with such a wide chromosome variation in Cynoglottis are discussed. Brunnera macrophylla and B. orientalis share a complement of 2n= 12 and an apparently identical karyotype, which differs from Cynoglottis in terms of asymmetry, chromosome size and morphology. A basic C-banding style was present in Brunnera and Cynoglottis , but heterochromatin content increased from the former to the latter. The parallel increase in chromosome number, heterochromatin content and size of the pollen from Brunnera to Cynoglottis may reflect an evolutionary progression, and is consistent with the supposed ancient origin of Brunnera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

双花木属和壳菜果属(金缕梅科)的核型研究

本文对金缕梅科Hamamelidaceae双花木属Disanthus Maxim．的长柄双花木D．cercidifolius subsp．longipes和单种属壳菜果属Mytilaria Lec.首次进行了染色体计数和核型分析。结果表明：长柄双花木与产自日本的双花木D. cercidifolius subsp．cercidifolius的体细胞染色体数目一致,均为2n＝16,前者无“st”或“t”染色体,表明该亚种可能比较原始;壳菜果Mytilaria laosensis Lec．的染色体数目为2n＝26,x=13。前人报道的金缕梅科染色体基数为x＝8和x＝12,因此x＝13可能是金缕梅科的一个新染色体基数。联系该属的形态特征及其与马蹄荷属Exbucklandia R．W．Brown的关系,作者支持将壳菜果属处理为独立的亚科,即壳菜果亚科Mytilarioideae。     

New or rare chromosome counts in the genera Artemisia L. and Mausolea Bunge (Asteraceae, Anthemideae) from Uzbekistan

Seventeen chromosome counts of 14 Artemisia and one Mausolea species are reported from Uzbekistan. Five of them are new reports, two are not consistent with previous counts and the remaining are confirmations of very scarce (one to four) previous data. Two basic chromosome numbers (x = 8 and x = 9) and two ploidy levels (2x and 4x) were found. Some correlations between ploidy level, morphological characters and distribution are noted.     

菰属系统与演化研究－－叶片表皮微形态

菰属叶片表皮微形态以其具有稻型的硅质体,指状的双胞微毛,三角形的副卫细胞,应位在禾本科(Gramineae)稻族(Oryzeae)内,但因其硅质体不整齐排列于脉上,而且有时呈现十字形或浅节结形,双胞微毛的顶细胞较粗壮等独特性状,结合染色体2n=2x=30,34,而区别于稻族中其他各属(x=12),且其所具竹亚科(Bambusoideae)的胚型(F+PP)在稻族中也鲜有,故应在稻族中独立成菰亚族(subtribeZizaniinae)。其属下种间的叶表皮微形态特征,大都吻合孢粉、外稃表皮微形态特征的研究结果,揭示菰属在全世界有4种,2亚种。     

A taxonomic revision of the Antennaria media (Asteraceae: Inuleae) polyploid species complex in western North America

TheAntennaria media polyploid species complex has been evaluated, at least in part, on numerous occasions without consensus on either the taxa that should be included within the complex or the rank at which these taxa should be recognized. The primary purpose of this quantitative, multivariate, phenetic study is to propose a taxonomy for the polyploid species complex that not only is independent of a knowledge of either chromosome number or reproductive biology but that concurrently minimally reflects morphological variation associated with each. The use of canonical discriminant analysis facilitates this purpose. In an attempt to maintain consistency with other recent revisions of polyploid complexes within the genus, the rank of subspecies (A. media subsp.media, A. media subsp.ciliata, A. media subsp.compacta, A. media subsp.fusca, andA. media subsp.pulchella) is selected as the infraspecific rank that satisfies the purpose of the phenetic study and is supported by the analyses. These subspecies differ to varying degrees with respect to reproductive characters (corolla length, pappus length), vegetative-reproductive characters (involucre length, peduncle length, cauline leaf length, cauline leaf width), and vegetative characters (basal leaf length and basal leaf width).Antennaria media subsp.pulchella is a sexually reproducing, diploid subspecies, whereas the remaining four subspecies are essentially agamospermous polyploids.     

A detailed study ofCrocus speciosus and its allyC. pulchellus (Iridaceae)

Crocus speciosus is a widely distributed autumn-flowering species showing considerable variation in its morphological characters. Three subspecies are recognised, two of which are endemic to small areas of Turkey. The third, subsp.speciosus, occurs in a much wider area and contains a number of different cytotypes.C. pulchellus is a distinct but closely related species. The morphological relationships between the species and subspecies are discussed and a key to the taxa is provided. Cytological data are given and a distribution map of the cytotypes is provided. A detailed study of the leaf anatomy is presented.     

Morphometric analysis of disjunctPapaver radicatum (Papaveraceae) populations in southern Norway

Morphometric relationships between populations ofPapaver radicatum within the southern Norwegian mountains were investigated using canonical variates analysis andWard's clustering on capsule and leaf character sets. The survey describes patterns of variation among 13 wild-scored populations from five geographically disjunct localities, usually assigned to five races or subspecies. Our results from wild-collected material largely support earlier findings based on univariate statistics on cultivated material. In general, populations from within a disjunct locality (=subspecies) are most similar to other populations from the same locality. However, the subspecies vary in the degree to which they are differentiated in capsule morphology. The subsp.groevudalense populations are morphologically close to the main group of subsp.ovatilobum populations. Subspp.intermedium andoeksendalense are clearly distinct from one another and from the other subspecies, whereas the single subsp.gjaerevolli population is more similar to theovatilobum/groevudalense complex. Variation in leaf characters showed only partial congruence with variation in capsule characters. The pattern of morphological relationships among the subspecies is thus more complex than previously thought. The subspecies may have become differentiated during a period of isolation, but such results alone cannot indicate the duration of such a period.     

菰属系统与演化研究——叶片表皮微形态

菰属叶片表皮微形态以其具有稻型的硅质体,指状的双胞微毛,三角形的副卫细胞,应位在禾本科(Gramineae)稻族(Oryzeae)内,但因其硅质体不整齐排列于脉上,而且有时呈现十字形或浅节结形,双胞微毛的顶细胞较粗壮等独特性状,结合染色体2n=2x=30,34,而区别于稻族中其他各属(x=12),且其所具竹亚科(Bambusoideae)的胚型(F+PP)在稻族中也鲜有,故应在稻族中独立成菰亚族(subtribe Zizaniinae).其属下种间的叶表皮微形态特征,大都吻合孢粉、外稃表皮微形态特征的研究结果,揭示菰属在全世界有4种,2亚种.     

Chemical differences in volatiles between Melittis melissophyllum L. subsp. melissophyllum and subsp. albida (Guss) P. W. Ball (Lamiaceae) determined by solid-phase microextraction (SPME) coupled with GC/FID and GC/MS

Melittis melissophyllum (Lamiaceae) is a perennial herb, typical of woody places, occurring in Italy with two subspecies, i.e., melissophyllum and albida. So far, the classification of these two taxa was only based on morphology, i.e., the presence of glandular trichomes, the dimension of the leaves, and the number of teeth on each side as the main discriminant characters. To find marker compounds to chemically discriminate the subsp. melissophyllum with respect to the subsp. albida, a solid-phase microextraction SPME analysis coupled with GC/FID (=flame ionization detector) and GC/MS was carried out. SPME proved to be a chemotaxonomically useful technique that permitted a clearly differentiation of the two subspecies at headspace level. The subsp. melissophyllum was characterized by high amount of the mushroom alcohol oct-1-en-3-ol and the phenolic coumarin, whilst the subsp. albida exhibited a high content in monoterpenes and sesquiterpenes, α-pinene, sabinene, and (E)-caryophyllene being the major compounds. Multivariate chemometric techniques, such as cluster analysis (CA) and principal-component analysis (PCA), were used to support chemical data and characterize the population according to the taxonomy. In addition, the micromorphology and distribution of glandular trichomes of both subspecies were studied by scanning electron microscopy (SEM).     

A multivariate morphometric delimitation of species boundaries in the South American genus <Emphasis Type="Italic">Nicoraepoa</Emphasis> (Poaceae: Pooideae: Poeae)

A multivariate morphometric study of the genus Nicoraepoa was carried out to examine patterns of morphological variation among the species and to identify additional characters to allow a clearer delimitation among species. Nicoraepoa is a taxonomically complex genus comprising seven species endemic to South America. Although most of the species are well delimited, two of them, N. andina and N. chonotica, are morphologically similar and very difficult to separate. The morphological variation among species, with overlapping morphological characters, pseudovivipary and possible hybridization make species boundaries unclear. In the present paper, sixty-seven characters were scored for a total of 216 specimens and analyzed using ordination, cluster and discriminant analyses. Based on multivariate results, we recognized species groups and morphological diagnostic characters that allow clearer species delimitation. As a result, N. chonotica has been transferred to N. andina as a subspecies that inhabit southern Patagonia. Other taxa could be recognized and delimited by diagnostic characters: N. erinacea, N. pugionifolia, N. stepparia, N. subenervis subsp. spegazziniana and N. subenervis subsp. subenervis. Moreover, we discuss the possibility that a new species from Bolivia, based on only one specimen, closely related to N. subenervis should be ascribed in Nicoraepoa.     

Morphological differentiation supports the genetic pattern of the geographic structure of Juniperus thurifera (Cupressaceae)

Juniperus thurifera is an important component of woodland communities of dry sites within the West Mediterranean region and is characterised by a strongly disjunctive geographic range. Two subspecies were recognised, subsp. thurifera in Europe and subsp. africana in Africa. The aim of the study was the comparison of phenetic diversity to the pattern of AFLP geographic differentiation of the species described in the literature. The examination of phenetic diversity was based on the biometrical analysis of 17 populations using 12 morphological characters of cone and seed. The differences among populations were analysed using Student’s t test, analysis of discrimination, UPGMA agglomeration and hierarchical analysis of variance. The majority of morphological characters differentiated at a statistically significant level between populations and between J. thurifera subsp. thurifera and subsp. africana. Three groups of populations were detected using multivariate statistical analyses. The first, well separated, is subsp. africana, while the following two concern subsp. thurifera. The morphological differentiation of populations appeared similar to that described on the AFLP. The Gibraltar Straight appeared to be the most important barrier.