Beitrag zur systematik vonScilla L. subgen.Scilla (inklusiveChionodoxa Boiss.)

Zusammenfassung Die vonBoissier aufgestellte GattungChionodoxa wird auf Grund samenanatomischer und karyologischer Befunde eingezogen. Ihre nahe Verwandtschaft mitScilla bifolia agg. konnte aufgezeigt werden. Die wesentlichen Unterschiede derScilla bifolia- Gruppe (inklusiveChionodoxa-Arten) zu anderen Gruppen myrmekochorerScilla-Arten sowie zuPuschkinia undHyacinthus wurden dargelegt.Folgende neue Kombinationen werden aufgestellt:Scilla luciliae (Boiss.)Speta comb. nova,Scilla cretica (Boiss. &Heldr.)Speta comb. nova,Scilla nana (Schult. fil.)Speta comb. nova,Scilla sardensis (Barr &Sugden)Speta comb. nova,Scilla siehei (Stapf)Speta comb. nova,Scilla×allenii (Nicholson)Speta comb. nova.Weiters wurden die Chromosomenzahlen für einigeScilla- Arten überprüft und dabei fürScilla bifolia neben der bekannten diploiden auch die tetraploide Zahl 2n=36 aufgefunden.

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Summary The genusChionodoxa set up byBoissier is withdrawn due to seedanatomical and caryological statements and its species are incorporated intoScilla L. The close affinity between formerChionodoxa-species andScilla bifolia agg. could be demonstrated. The essential differences between theScilla bifolia group (including the formerChionodoxa species) and other groups of myrmecochorousScilla species,Puschkinia andHyacinthus were shown. The following new combinations are set up:Scella luciliae (Boiss.)Speta comb. nova,Scilla cretica (Boiss. &Heldr.)Speta comb. nova,Scilla nana (Schult. fil.)Speta comb. nova,Scilla sardensis (Barr &Sugden)Speta comb. nova,Scilla siehei (Stapf)Speta comb. nova,Scilla×allenii (Nicholson)Speta comb. nova.Furthermore the chromosome numbers of someScilla species were checked, and inScilla bifolia L. besides the known diploid number the tetraploid number 2n=36 was discovered.

     

Ricerche Citotassonomiche in Artemisia Vulgaris L. Ed Artemisia Verlotorum Lamotte

Abstract

Cytotaxonomical studies in Artemisia vulgaris L. and Artemisia verlotorum Lamotte. — Karyotype analysis of A. vulgaris and A. verlotorum has shown in the first species, in agreement with previous data, a chromosome number of 2n=16 and in the second the chromosome number of 2n=48 which does not agree with previous data. This seems to be the first case of polyploidy observed in Artemisia with basic number eight. A few specimens of A. verlotorum had shown 2n=48 + 2B chromosomes. The comparison of karyotypes has shown that, while the two species have, in some respect, the same degree of symmetry (ΣL%=57; ΣC9% = 43), the quality of their chromosomes is different (see karyotype formulas). We see no explanation for such an unlikely phenomenon.     

CHROMOSOME MORPHOLOGY IN THE GENUS SAMBUCUS

Two basic chromosome karyotypes were found in the genus Sambucus. Chromosome numbers were observed to be 2n = 38 for S. callicarpa, S. cerulea, S. glauca, S. kamtschatica, S. melanocarpa, S. mexicana, S. miquelli, S. sibirica, and S. sieboldiana and 2n = 36 for S. simpsonii and S. williamsii. Measurements of 18 karyotypes are presented. The major differences between the two basic chromosome karyotypes can be explained as the result of a mis-division of a metacentric chromosome giving rise to two telocentric chromosomes, thus reducing the number of metacentrics from five to four and increasing the chromosome number from 2n = 36 to 2n = 38. Observed chromosome aberrations and aneuploidy may result from unstable telocentric chromosomes.     

Chromosome Localization of 5S and 45S Ribosomal DNA in the Genomes of Linum L. Species of the Section Linum (Syn. Protolinum and Adenolinum)

Fluorescence in situ hybridization (FISH) was for the first time used to study the chromosomal location of the 45S (18S–5.8S–26S) and 5S ribosomal genes in the genomes of five flax species of the section Linum (syn. Protolinum and Adenolinum). In L. usitatissimum L. (2n = 30), L. angustifolium Huds. (2n = 30), and L. bienne Mill. (2n = 30), a major hybridization site of 45S rDNA was observed in the pericentric region of a large metacentric chromosome. A polymorphic minor locus of 45S rDNA was found on one of the small chromosomes. Sites of 5S rDNA were colocalized with those of 45S rDNA, but direct correlation between signal intensities from the 45S and 5S rDNA sites was observed only in some cases. Other 5S rDNA sites mapped to two chromosomes in these flax species. In L. grandiflorum Desf. (2n = 16) and L. austriacum L. (2n = 18), large regions of 45S and 5S rDNA were similarly located on a pair of homologous satellite-bearing chromosomes. An additional large polymorphic site of 45S and 5S rDNA was found in the proximal region of one arm of a small chromosome in the L. usitatissimum, L. angustifolium, and L. bienne karyotypes. The other arm of this chromosome contained a large 5S rDNA cluster. A similar location of the ribosomal genes in the pericentric region of the pair of satellite-bearing metacentrics confirmed the close relationships of the species examined. The difference in chromosomal location of the ribosomal genes between flax species with 2n = 30 and those with 2n = 16 or 18 testified to their assignment to different sections. The use of ribosomal genes as chromosome markers was assumed to be of importance for comparative genomic studies in cultivated flax, a valuable crop species of Russia, and in its wild relatives.     

Cytogenetics of the Scilla scilloides complex

There are two cytogenetically well differentiated genomes, A (x=8) and B (x=9), in the Scilla scilloides complex. The principal cytogenetic types form an aneuploidal series of chromosome numbers, i.e., AA (2n=16), BB (2n=18), ABB (2n=26), BBB (2n=27), AABB (2n=34), ABBB (2n=35), BBBB (2n=36), and AABBB (2n=43). These types are widespread in the Japanese islands, excepting AA which is confined to Korea. On the contrary diploid BB is not known from Korea. However, polyploids AABB and AABBB are known from both Japan and Korea.Plants of the complex do not grow in wild lands or montane regions, but in close relation to man's activities, e.g., in agricultural lands, on river banks, along roadways and railway lines, and in graveyards. Natural populations are, as a rule, a mixture of many different cytogenetic types.The present study was supported financially by a Grant-in-Aid for Fundamental Scientific Research from the Japanese Ministry of Education; No. (A) 0810.     

Ricerche Embriologiche Sul Genere Thalictrum. II. Embriologia e Cariologia Di Thalictrum Lucidum L. e di Thalictrum Minus L. Subsp. Minus

Abstract

Embryological researches in the «Thalictrum» genus. II. Embryology and caryology of «Thalictrum lucidum» L. and «Thalictrum minus» L. ssp. «minus». — In their development the female gametophytes of Thalictrum lucidum L. and Thalictrum minus L. ssp. minus follow the Normal type. In the female gametophytes of these species several types of antipodal cells occurs such as: their considerable enlargement, formation of many antipodals polyploid or polinucleated antipodal cells. In these various types, however, a rapid regression of the antipodals occurs. In T. lucidum some tendency to a disposition of the tetrapolarized type has been verified. The chromosome number has been confirmed to ben 2n=28 in besides, in the pollen development, many cases of regression of the microspores has been verified. The chromosome number has been confirmed to ben 2n=28 in Thalictrum lucidum L., and has been found to ben 2n=14 in Thalictrum minus L. ssp. minus, a new number in this species, which was earlier reported to have 2n=42.     

Amount of DNA complementary to ribosomal RNA in polyploid series of Scilla autumnalis L. and Urginea maritima (L.) Baker

Abstract

The percentage of rDNA in polyploid series of Scilla autumnalis and Urginea maritima has been determined by hybridization experiments rRNA/DNA. Previous reports indicate that a regulation of the number of rRNA cistrons exists in polyploid plants, but other works are in contrast with this assertion. We find approximately the same percentage of rDNA in species with different ploidy. We conclude that in the species examined does not exist a regulation of the ribosomal RNA genes.     

Characterization of heterochromatin in different species of the Scilla siberica group (Liliaceae) by in situ hybridization of satellite DNAs and fluorochrome banding

Satellite DNAs have been isolated from the monocotyledonous plants Scilla siberica, S. amoena, S. ingridae (all are highly GC-rich), and S. mischtschenkoana by using the Ag⁺ –Cs₂SO₄ density centrifugation technique. Hybridization in situ has been performed with ₃H-cRNA to these satellite DNAs in all four species. In each species, the endogenous satellite DNA is located mainly in intercalary and major heterochromatin bands associated with terminal regions and nucleolar organizer regions (NORs) but not in centromeric regions. Patterns observed after cross-species hybridization show a high degree of satellite DNA homology between S. siberica, S. amoena, and S. ingridae. By contrast, satellite DNA of S. mischtschenkoana consists largely of different, non homologous DNA sequences, with two exceptions: (i) the NORs of all four species contain similar satellite sequences, and (ii) a strong homology exists between the satellite DNA of S. mischtschenkoana and centromeric DNA of S. siberica but not with those of S. amoena and S. ingridae. — Heterochromatin has also been characterized by the AT-specific fluorochromes quinacrine (Q) and DAPI and the GC-specific agent chromomycin A₃ (CMA₃), in combination with two counterstaining techniques. While CMA₃-fluorescence is largely in agreement with data on base composition and location of the specific satellite DNAs, the results with Q and DAPI are conflicting. Prolonged fixation has been found to change the fluorescence character in certain instances, indicating that other factors than the base sequence of the DNA also play a role in fluorochrome staining of chromosomes. The results are discussed in relation to the taxonomy and phylogeny of the four species.     

Karyotype variation within some native populations of oriental spruce (<Emphasis Type="Italic">Picea orientalis</Emphasis>) in Turkey

Karyological studies have been investigated within 8 native Anatolian populations of oriental spruce (Picea orientalis (L.) Link) in Turkey. The somatic chromosome number of 2n = 2x = 24 has been observed in all accessions. The karyotypes are generally asymmetrical with most of the chromosomes having median to median-submedian centromeres. Inter-population variability of the karyotype was summarized with cluster analysis. We found that the karyotypes have positively correlated with the altitudes of the natural habitats. The high value of karyotype asymmetry may be attributed to both microenvironment and natural regeneration methods used in oriental spruce.     

Heterochromatin recognition and analysis of chromosome variation in Scilla sibirica

The heteroohromatin of Scilla sibirica, consists of two distinct types: 1) showing enhanced Quinacrine fluorescence and located near the centromere of all the chromosomes of the complement, and 2) with reduced Quinacrine fluorescence and located in various positions along the chromosomes. After a denaturation-reannealing treatment both heterochromatin types are stained by Giemsa, and by acetic-orcein. Acetic-orcein, however, tends to stain preferentially the reduced fluorescence segments. An analysis of chromosome variation in a population of twenty plants, reveals that all the plants are unique in their heterochromatic segment endowment. All the chromosomes are polymorphic but there is a certain constancy for band patterns in individual chromosome types, and for the number of bands per chromosome complement.     

Karyology and phylogeny of some Mesoamerican species of Zamia (Zamiaceae)

Chromosome numbers and karyotypes of four species of Zamia L. (Zamiaceae) are described. Plants of Z. manicata from Colombia are 2n = 18 with eight metacentric (M), four submetacentric (S), two acrocentric (A), and four telocentric (T) chromosomes. Plants of Z. ipetiensis from Panama are 2n = 23 with 3M + 4S + 2A + 14T. Plants of Z. cunaria from Panama have two different chromosome numbers, 2n = 23 with 3M + 4S + 2A + 14T and 2n = 24 with 2M + 4S + 2A + 16T. Plants of Z. acuminata from Costa Rica and Panama are 2n = 24 with 2M + 4S + 2A + 16T. On the basis of the occurrence of a one-to-two-ratio in the variation of M- and T-chromosome numbers in the karyotypes, centric fission or fusion are considered for their potential involvement in the chromosome variation of these plants. Data deriving from morphology and karyology, interpreted in a cladistic framework, suggest that centric fission rather than centric fusion is involved in the karyotype diversification of the four species and their closest Mesoamerican allies.     

Comparison of genomes of eight species of sections <Emphasis Type="Italic">Linum</Emphasis> and <Emphasis Type="Italic">Adenolinum</Emphasis> from the genus<Emphasis Type="Italic"> Linum</Emphasis> based on chromosome banding,molecular markers and RAPD analysis

Karyotypes of species sects. Linum and Adenolinum have been studied using C/DAPI-banding, Ag-NOR staining, FISH with 5S and 26S rDNA and RAPD analysis. C/DAPI-banding patterns enabled identification of all homologous chromosome pairs in the studied karyotypes. The revealed high similarity between species L. grandiflorum (2n = 16) and L. decumbens by chromosome and molecular markers proved their close genome relationship and identified the chromosome number in L. decumbens as 2n = 16. The similarity found for C/DAPI-banding patterns between species with the same chromosome numbers corresponds with the results obtained by RAPD-analysis, showing clusterization of 16-, 18- and 30-chromosome species into three separate groups. 5S rDNA and 26S rDNA were co-localized in NOR-chromosome 1 in the genomes of all species investigated. In 30-chromosome species, there were three separate 5S rDNA sites in chromosomes 3, 8 and 13. In 16-chromosome species, a separate 5S rDNA site was also located in chromosome 3, whereas in 18-chromosome species it was found in the long arm of NOR-chromosome 1. Thus, the difference in localization of rDNA sites in species with 2n = 16, 2n = 30 and 2n = 18 confirms taxonomists opinion, who attributed these species to different sects. Linum and Adenolinum, respectively. The obtained results suggest that species with 2n = 16, 2n = 18 and 2n = 30 originated from a 16-chromosome ancestor.     

Comparative Genome Analysis in Two Flax Species by C-Banding Patterns

C-banding patterns of the karyotypes of two closely related wild flax species, Linum austriacumL. (2n= 18) and Linum grandiflorumDesf. (2n= 16), were studied. The karyotypes of both species were similar in the chromosome morphology and size. In each species, metacentric and acrocentric chromosomes (1.7–4.3 m) and one satellite chromosome were observed. In the karyotypes of the species studied, all homologous chromosome pairs were identified, and quantitative idiograms were constructed. Eight chromosome pairs in the two species had similar C-banding patterns. A low level of intraspecific polymorphism in the intercalary and telomeric C-bands was shown in both species. The results indicate that the genomes of two flax species originated from one ancestral genome with the basic chromosome number of 8 or 9. Apparently, the duplication or loss of one chromosome with subsequent redistribution of the chromosome material in the ancestral form resulted in the divergence into two species,L. austriacumL. and L. grandiflorumDesf. A considerable similarity of chromosomes in these species provides evidence for their close phylogenetic relatedness, which makes it possible to place them in one section within the Linumgenus.     

扇脉杓兰和无距虾脊兰的核型分析

为了解扇脉杓兰(Cypripedium japonicum Thunb.)和无距虾脊兰(Calanthe tsoongiana T. Tang et F. T. Wang)的核型,采用根尖压片法对扇脉杓兰和无距虾脊兰的染色体数目和核型进行了研究。结果表明,扇脉杓兰体细胞的染色体数为22,核型公式为2n=2x=22=16m+2sm+2st+2t,染色体相对长度组成为2n=22=2L+6M2+12M1+2S,核不对称系数为60.01%,核型分类为2B型;而无距虾脊兰体细胞的染色体数为40,核型公式为2n=2x=40=28m+10sm+2st,染色体相对长度组成为2n=40=8L+10M2+16M1+6S,核不对称系数为59.84%,核型分类为2B型;两者核型都较为对称。其中,无距虾脊兰的核型为首次报道。这为扇脉杓兰和无距虾脊兰的进化地位和种质保护提供了细胞学证据。     

CYTOGENETIC STUDIES IN CLARKIA,SECTION PRIMIGENIA. IV. A CYTOLOGICAL SURVEY OF CLARKIA GRACILIS

Clarkia gracilis (2n = 28) is an allotetraploid which combines genomes from two subsections of section Primigenia. Natural populations consist of plants homozygous for a single chromosome arrangement, which may differ from the arrangements in other populations by one or more reciprocal translocations. One arrangement, the “standard,” was widespread. Cytological observations on plants derived from crosses between populations of C. gracilis, and on triploid plants derived from crosses with C. amoena subsp. huntiana, one of the parents of the tetraploid, were used to determine the end arrangements present. Ten arrangements were identified, and it was found that the standard amoena subgenome of C. gracilis is identical in end arrangement to the previously defined standard arrangement of the diploid C. amoena. Hence a race of C. amoena with this arrangement was involved in the hybridization which gave rise to C. gracilis. Evidence was found that other arrangements of C. amoena have probably been introduced into C. gracilis by subsequent introgressive hybridization. Cytological differences, coupled with differences in morphology, ecology, and distribution indicate that C. gracilis should be subdivided into four subspecies instead of the three presently recognized.     

Chromosome number and DNA ploidy level reports from Central Europe — 3

Third part of chromosome number and DNA ploidy level reports from Central Europe comprising whole Carpatho-Pannonian region includes the data for following taxa: Scilla bifolia s. str. (2n = 18), S. bifolia agg. (2n = 36, 54), S. drunensis subsp. drunensis (2n = 36), S. drunensis subsp. buekkensis (2n = 36), S. kladnii (2n = 18) and S. vindobonensis (2n = 18) by J. Kochjarová from Austria, Slovakia and the Czech Republic (nos. 27–32); Campanula macrostachya (2n = ca 32) and Erysimum diffusum (2n = 14, 28) by E. Michalková from Hungary (nos. 33–34). Original unpublished reports should be sent to the editor on following address: patrik.mraz@upjs.sk. For further details and arrangements of reports see the first part (Mráz 2005). Previous parts of the reports were published in 2005 and 2006 (Mráz 2005, 2006).     

Karyotype analysis and new chromosome number reports in <Emphasis Type="Italic">Silene</Emphasis> species (sect. <Emphasis Type="Italic">Auriculatae</Emphasis>, Caryophyllaceae)

Karyotype study was performed in 13 populations of 11 Silene species (sect. Auriculatae L., Caryophyllaceae) growing in Iran. All the species studied showed 2n = 2x = 24 chromosome number supporting the earlier report on S. meyeri, while the chromosome number of S. palinotricha, S. sojakii, S. gertraudiae, S. elymaitica, S. pseudonurensis, S. dschuparensis, S. eriocalycina, S. araratica, S. prilipkoana and S. commelinifolia are new to science. The chromosomes were mainly metacentric or sub-metacentric and their size varied from 1.10 μm in S. pseudonurensis to 7.11 μm in S. dschuparensis. The species studied differed significantly in the total size of the chromosomes, the size of the short arms and the long arms, indicating the role of quantitative genomic changes in the Silene species diversification. They also differ in their karyotype formulae indicating the occurrence of structural changes in their chromosomes. The Silene species were placed in 1A, 2A, 1B and 2B classes of Stebbins karyotype symmetry showing symmetrical karyotypes. Clustering of the species based on karyotype features grouped the species of S. palinotricha, S. prilipkoana, S. commelinifolia, S. eriocalycina, S. meyeri, S. araratica and S. Sojakii together while the species of S. gertraudiae and S. elymaitica showed more similarity and were placed close to each other.     

Widespread Chromosome Variation in the Endangered Grassland Forb Rutidosis leptorrhynchoides F. Muell. (Asteraceae: Gnaphalieae)

Rutidosis leptorrhynchoides is an endangered plant endemic tosoutheastern Australia. Chromosome analysis of 19 of the 24known populations of the species has identified 17 differentchromosome variants or cytotypes. The most common cytotypesare a diploid and a tetraploid based on x = 11, and triploidand hexaploid plants with this basic number were also observed.Diploids, triploids and tetraploids based on a second basicnumber ofx = 13 were also seen. Plants with 2 n = 24 were shownto be hybrids between diploids with the two different basicnumbers. Meiotic chromosome pairing analysis of the plants with2n = 24 showed a maximum of two trivalents indicating the presenceof extra copies of one pair of large and one pair of small chromosomesin the 2 n = 26 plants. In addition, a number of different aneuploidsof the 2 n = 22 and 2 n = 44 races were found and many of thesealso showed structural chromosomal variation. The distributionof the two main chromosome races is disjunct with the tetraploidsconfined to southern Victoria. To avoid dysgenic effects, futurere-establishment efforts for this species should avoid mixingseed from different chromosome races. Copyright 2001 Annalsof Botany Company Aneuploidy, conservation genetics, karyotypes, meiosis, polyploidy     

Biosystematic study ofSedum L. SubgenusAizoon (Crassulaceae)

Variation in chromosome number and morphological characters ofSedum aizoon L. var.floribundum Nakai were investigated to analyze, correlations between them. Geographical variation in chromosome number was also examined. Chromosome numbers of 189 individuals from 55 localities were counted as 2n=32, 33, 34, 48, 61, 64, 78, 80, 84, 85, 88, 93, 94, 95, 96, 97 and 102. InSedum subgenusAizoon, which has the basic number of X=8, var.floribundum of the speciesaizoon showed a polyploid series from tetraploid to dodecaploid. Tetraploids were found most frequently in this variety. More than two chromosome numbers were found in all the populations with 2n=61 or more. Tetraploids were mainly distributed in the eastern part of Japan, and higher polyploids (higher than hexaploid level except octaploids) were distributed in the western part of Japan. Thirteen morphological characters were examined in 119 individuals belonging to 30 populations. The principal component analysis and the cluster analysis of these characters indicated that populations with similar chromosome numbers were not always morphologically similar. Ten morphotypes can be recognized based on the combination of chromosome number and morphological characters. ThusS. aizoon var.floribundum can be regarded as a polyploid-aneuploid complex.     

The B chromosome system of Scilla autumnalis (Liliaceae): effects at the isozyme level

Supernumerary (B) chromosomes have been studied in a Spanish population of Scilla autumnalis L. (Liliaceae). Out of the 140 individuals analysed, seven had 2n=14+1B, one 2n=14+2B, one 2n=14+3B and one 2n=14+9B. An analysis of esterase isozyme patterns shows that all 130 individuals with a standard karyotype (2n=14) have two esterase loci, Est-2 and Est-3, whereas all 10 individuals with Bs have three, Est-1, Est-2 and Est-3, irrespective of the precise number of Bs present. The role that the Bs may have played in the appearance of this new locus (Est-1) is discussed in relation to their possible origin.