The allopolyploid origin ofSedum rupestre subsp.rupestre (Crassulaceae)

InSedum rupestre L. a polyploid series (x = 16) occurs in which aneuploid chromosome numbers and odd levels of ploidy prevail. The most common and widely distributed cytotype,S. rupestre subsp.rupestre, is 2n = 112. Plants resemblingS. rupestre subsp.rupestre can be obtained by hybridizing the tetraploid cytotypes ofS. forsterianum Sm. (2n = 48) andS. rupestre subsp.erectum 't Hart (2n = 64). Comparison of these artificial hybrids with their parents and a large number of plants ofS. rupestre subsp.rupestre (2n = 112) from nature showed thatS. rupestre subsp.rupestre and the artificial hybrids are morphologically indistinguishable, and intermediate betweenS. forsterianum andS. rupestre subsp.erectum. MorphologicallyS. rupestre subsp.rupestre is closer to subsp.erectum than toS. forsterianum. Chloroplast DNA restriction patterns ofS. rupestre subsp.rupestre, however, resembleS. forsterianum more closely. The combined results of the hybridization experiments, the analysis of the cpDNA restriction patterns, and the morphological variation indicate the allopolyploid origin ofS. rupestre subsp.rupestre. Natural hybrids inSedum (Crassulaceae) 4.     

Giemsa karyotypes and their evolutionary significance inScilla bifolia,S. drunensis,andS. vindobonensis (Liliaceae)

Quantitatively evaluated C-banded and conventional karyograms are presented for the related speciesScilla bifolia subsp.danubialis Speta,S. drunensis (Speta)Speta, andS. vindobonensis Speta. On the basis of banding patterns and karyotype structureS. bifolia subsp.danubialis (2n = 18, 2×) andS. drunensis (2n = 36, 4×) are quite similar, whileS. vindobonensis (2n = 18, 2×) is entirely different. There is a moderate degree of karyotypic variation withinS. bifolia subsp.danubialis andS. drunensis. However, inS. vindobonensis karyotypes and banding patterns are almost completely stable over a geographical range of about 500 km. The present results confirm the recent taxonomic separation ofS. vindobonensis fromS. bifolia, and suggest a considerable phylogenetic distance between these two diploid species. The results are discussed with reference to the morphological characters of the species and their geographical distribution.Evolution ofScilla and Related Genera, II.Dedicated to Univ.-Prof. Dr.Elisabeth Tschermak-Woess on the occasion of her 60th birthday.     

Allozyme variation in the annual weed species complexPolygonum aviculare (Polygonaceae) in relation to ploidy level and colonizing ability

Variation at six polymorphic enzymatic loci was studied in 50 populations of the selfing annualPolygonum aviculare from Belgium. The results show that theP. aviculare complex has an allopolyploid origin and comprises two main genetic entities, viz.P. aviculare subsp.depressum (2n = 4x = 40), restricted to urban sites subject to trampling stress, andP. aviculare subsp.aviculare (2n = 4x = 40, 2n = 6x = 60), with a wider ecological amplitude. The latter had a higher genetic diversity and a higher frequency of fixed heterozygosity than the former. WithinP. aviculare subsp.aviculare, genetic diversity and ecological amplitude correlated positively with ploidy level. Additionally, stronger genetic differentiation among and lower variation within populations was found in urban areas than in cultivated fields.     

On the taxonomic position ofSilene thebana (Caryophyllaceae)

Silene thebana Orph. exBoiss. is transferred as a subspecies toS. fabaria (L.)Sm., resulting in the new combinationS. fabaria (L.)Sm. subsp.thebana (Orph. exBoiss.)Melzh. The chromosome count of 2n = 24 is recorded for the first time for this taxon.Dedicated to Prof. DrK. H. Rechinger on the occasion of his 80th birthday, 16th October 1986.     

Delimitation ofPelargonium sect.Glaucophyllum (Geraniaceae)

Pelargonium otaviense Knuth andP. spinosum Willd. are excluded from sect.Glaucophyllum, whileP. grandiflorum (Andr.)Willd.,P. patulum Jacq. andP. tabulare (Burm. f.)L'Hérit. of sect.Eumorpha are included. Sect.Glaucophyllum is characterized by green to glaucous vegetative organs and zygomorphic white to pink corolla with five narrow petals. All the species have an identical pollen and chromosome morphology, the same basic chromosome number (x = 11) and similar flavonoid patterns. A close relationship between sect.Glaucophyllum and sect.Pelargonium is indicated by the occurrence of natural hybrids and concordant characters. Isorhamnetin and luteolin have been detected in the genus for the first time.     

Cytology ofCrocus sativus and its allies (Iridaceae)

Populations ofC. cartwrightianus, C. hadriaticus andC. thomasii from the Balkans have 2n = 16 as has the Middle EasternC. pallasii subsp.haussknechtii. C. dispathaceus andC. pallasii subsp.pallasii have 2n = 14 whileC. pallasii subsp.turcicus has 2n = 12.C. niveus has 2n = 28 andC. sativus is an autotriploid with 2n = 24. Karyotype variation was found between populations ofC. pallasii subsp.pallasii in Central Turkey and also inC. pallasii subsp.turcicus.     

Zwei neue Arten der GattungSaponaria (Caryophyllaceae) aus Afghanistan und Pakistan

Saponaria stenopetala sp.n. in Eastern Afghanistan is close toS. pachyphylla Rech. f. andS. subrosularis Rech. f.—The nearest allies ofS. makranica sp.n. from Western Pakistan and Southeastern Iran areS. kermanensis Bornm. andS. floribunda (Kar. & Kir.)Boiss.

Flora Iranicae praecursores 36–37. — Praecursores praecurrentes in Pl. Syst. Evol.139, 313–317 (1982).     

Chromosome numbers and taxonomic implications in the fern genusAzolla (Azollaceae)

Investigation of chromosome numbers of allAzolla species, and for the first time of hybrids, has been undertaken. Removal of wax from the leaf surface proved invaluable in achieving clear cytological preparations and providing unambiguous chromosome numbers. In contrast to previous records, the speciesA. pinnata, A. filiculoides, A. filiculoides var.rubra, A. caroliniana, A. microphylla, andA. mexicana were found to be 2n=44, andA. nilotica to be 2n=52. Several triploids (2n=66) and one tetraploid (2n=88) were identified. No geographical pattern could be observed in the distribution of triploids which probably derive from the function of unreduced gametes. The chromosome number of hybrids occasionally deviates from the diploid chromosome number (2n=44). The small chromosome size limits karyotypic analysis and only differences in overall chromosome size can be observed. Taxonomic implications of chromosome numbers and sizes are discussed.     

Cytotaxonomical studies on AsianAnnonaceae

Chromosome numbers of 42 species and 3 varieties from 24 genera of theAnnonaceae have been determined (Table 1); reports for 15 of the genera are new. Among Asian genera 2n = 14 occurs only in the specializedMezzettia, while 2n = 16 is wide-spread and also has been found inAnaxagorea with some primitive characters. 2n = 18 is reported for 11 genera, and tetraploidy (2n = 36) has been observed inPolyalthia. Therefore, an original basic number of x = 8 or x = 9 is suggested at least for the Asian genera of theAnnonaceae.—Cytotaxonomical notes on the critical speciesPolyalthia rumphii andP. affinis are given, and the new combinationNeouvaria parallelivenia (Boerl.)Okada & Ueda is proposed.     

Chromosome numbers and pollen fertility in the Senecio nemorensis group (Compositae) in the Carpathians

New chromosome numbers for two species from the Senecio nemorensis group: S. dacicus (2n = 40) and S. ucranicus (2n = 40) have been ascertained. The counts for S. germanicus Wallr. subsp. germanicus (2n = 40), S. hercynicus Herborg subsp. hercynicus (2n = 40), S. ovatus (P. Gaertn. et al.) Willd. subsp. ovatus (2n = 40) occurring in the Carpathians are also reported. The study confirmed only the known tetraploid chromosome number for the taxa of this group. The pollen fertility ranged from 82.09 to 92.99% in all examined species and subspecies, including their hybrids.     

Chromosome numbers of the European seagrasses

The chromosome numbers of the five European seagrasses have been determined in material from several sites along the coasts of the Atlantic Ocean, the North Sea and the Mediterranean:Zostera marina L., 2n = 12;Z. noltii Hornem., 2n = 12;Posidonia oceanica (L.)Delile, 2n = 20;Cymodocea nodosa (Ucria)Aschers., 2n = 14, 2n = 28;Halophila stipulacea (Forsk.)Aschers., 2n = 18. The difference in chromosome morphology betweenZ. marina andZ. noltii supports the division of the genus into two subgenera.     

An analysis of interspecific hybrids and phylogenetic implications inCucumis (Cucurbitaceae)

Investigations on interspecific crossability in 8Cucumis species (2n = 24) and chromosome pairing and pollen fertility of their hybrids from 15 combinations have been utilized for tracing the phylogenetic relationships among these taxa and factors responsible for their differentiation. A collective evaluation of data suggests that there are three broad groups of species, one of the spiny fruited interfertile species, whose hybrids show varying degree of chromosome associations and low to high pollen fertility; the second of species with non-spiny fruits, which are completely incompatible with the former but weakly compatible with the cultivated species,C. melo L. to produce partly developed seeds, and the third group ofC. metuliferus E. Mey. exSchrad. andC. melo and its different botanical varieties. The species with spiny fruits can be further divided based on karyomorphological similarities and/or on relative genomic affinity, indicated by chromosome pairing and hybrid pollen fertility.Cytogenetics inCucumis III.     

Genetic relationships betweenLupinus pilosus andL. palaestinus (Fabaceae)

Lupinus pilosus Murr. andL. palaestinus Boiss., are both East Mediterranean annuals, greatly resemble each other in morphology, and have the same chromosome number (2n = 42). Some fertile hybrids can be formed by artificial hybridization or under unusual habitat conditions. Isolation in nature between the species is, however, maintained by prevalent selfing, partial reproductive barriers and genic imbalance, together with differences in ecological requirements. It is suggested that this speciation pattern which includes little morphological and hardly any chromosomal divergence might have occurred in other cases of edaphic vicariants too.     

Variation of Giemsa C-band and fluorochrome banded karyotypes,and relationships inAllium subgen.Molium

The somatic karyotypes of 10 taxa belonging toAllium subgen.Molium (Liliaceae) from the Mediterranean area have been investigated using Giemsa C-band and fluorochrome (Hoechst, Quinacrine) banding techniques. A wide range of banding patterns has been revealed. InAllium moly (2n = 14),A. oreophilum (2n = 16) andA. paradoxum (2n = 16) C-banding is restricted to a region on each side of the nucleolar organisers and the satellites show reduced fluorescence with fluorochromes. The satellites are also C-banded and with reduced fluorescence inA. triquetrum (2n = 18), but two other chromosome pairs also have telomeric bands which are not distinguished by fluorochrome treatment. InA. erdelii (2n = 16) 4 pairs of metacentric chromosomes have telomeric C-bands while 2 pairs of telocentric chromosomes have centromeric C-banding. InA. subhirsutum (2n = 14),A. neapolitanum (2n = 28),A. trifoliatum subsp.hirsutum (2n = 14) andA. trifoliatum subsp.trifoliatum (2n = 21) chromosomes with long centromeres, consisting of a centromere and nucleolar organiser are positively C-banded on each side of the constriction. InA. subhirsutum banding is confined to the pair of chromosomes with this feature, whereas inA. neapolitanum one additional chromosome pair has telomeric bands and inA. trifoliatum there are varying numbers of chromosomes with centromeric and telomeric bands, depending on the subspecies.A. zebdanense (2n = 18) shows no C-bands. The banding patterns in this subgenus are compared with those recorded for otherAllium species and with the sectional divisions in the genus. Evidence from the banding patterns for allopolyploidy inA. trifoliatum subsp.trifoliatum andA. neapolitanum is discussed.     

Production and cytogenetic analysis of intergeneric hybrids betweenElymus anthosachnoides andPsathyrostachys huashanica (Poaceae: Triticeae)

Intergeneric hybridization betweenElymus anthosachnoides (2n = 28,SSYY) andPsathyrostachys huashanica (2n = 14,NN) was performed. Three hybrid plants, obtained via embryo rescue, were intermediate between the parents in morphology and developed vigorously, but were completely sterile. The mean chromosome configuration was 19.48 I + 0.76 II per cell in the hybrids at meiotic metaphase I. This result indicates thatE. anthosachnoides andP. huashanica are distantly related and that there is little or no homoeology betweenN (P. huashanica) andS orY (E. anthosachnoides) genomes.     

Stachys beckeana (Labiatae) in Albanien und Jugoslawien

Morphological and cytological investigations were carried out inStachys beckeana Dörfler & Hayek andS. recta L. subsp.sarajevensis sensuHayek. These two taxa have the same morphological characteristics (shape and indumentum of leaves; morphology of sepals, petals and fruits) and both have 2n = 2x = 34 chromosomes. They cannot be considered as different taxa;S. beckeana Dörfler & Hayek is the valid name (synonyms:S. recta L. subsp.sarajevensis sensuHayek,S. hayekii Malý,S. recta L. subsp.hayekii Malý).

Erster Beitrag zur Neubearbeitung der Artengruppe derStachys recta L.     

Zwei neue Hybriden in der GattungEuphrasia (Scrophulariaceae)

The following new hybrids are described:Euphrasia ×dilata = E. hirtella Jordan exReuter ×alpina Lam.;Euphrasia ×trikoviana = E. tricuspidata L. ×rostkoviana Hayne. The chromosome number ofEuphrasia tricuspidata L. has been established for the first time: 2n = 22.

     

Interspecific hybridizations among species of theElymus semicostatus andElymus tibeticus groups (Poaceae)

Interspecific hybridizations were made between species of theE. semicostatus group, viz.,E. semicostatus (Nees exSteud.)Meld.,E. validus (Meld.)B. Salomon,E. abolinii (Drob.)Tzvel., andE. fedtschenkoi Tzvel., and species of theE. tibeticus group, viz.,E. pendulinus (Nevski)Tzvel.,E. tibeticus (Meld.)Singh,E. shandongensis B. Salomon, andE. gmelinii (Ledeb.)Tzvel., as well as among species within theE. tibeticus group. All species are tetraploid (2n = 4x = 28) and possess SY genomes. Meiotic pairing data from 24 hybrids involving 17 interspecific combinations are presented. The average number of chiasmata per cell ranged from 17.91 to 26.20 in hybrids within theE. tibeticus group, compared with 7.26 to 22.04 in hybrids between the two species groups. Despite the extensive collection of cytological data, there was no definite evidence for confirming or disproving the separate existence of the two groups.     

Intergeneric hybridization and C-banding patterns inHordelymus (Triticeae,Poaceae)

Crosses ofHordelymus europaeus (2n = 4x = 28) with four genera in theTriticeae were attempted. Adult hybrids were obtained in combinations withHordeum bogdanii (2x),Hordeum depressum (4x), andSecale cereale (2x). The meiotic pairing was very low in the hybrids withH. bogdanii andSecale cereale (0.12 and 0.30 chiasmata/cell, respectively), whereas high pairing (9.90 chiasmata/cell) was found in hybrids withH. depressum due to autosyndetic pairing ofH. depressum chromosomes. The chromosome complement ofHordelymus europaeus comprised 16 metacentrics, 8 submetacentrics, and 4 SAT-chromosomes. The Giemsa C-banding patterns of the chromosomes were characterized by small to minute bands at no preferential positions. It is hypothesized thatHordelymus europaeus may genomically be closest related toTaeniatherum andPsathyrostachys spp.     

Morphology and cytology of intergeneric hybrids involvingLeymus multicaulis (Poaceae)

The morphology and meiotic behaviour of pollen mother cells were studied in hybrids involvingLeymus multicaulis (2n = 28) ×Psathyrostachys huashanica (2n = 14),L. multicaulis ×P. juncea (2n = 14), andL. secalinus (2n = 28) ×L. multicaulis. Chromosome pairing was almost identical in theL. multicaulis ×P. huashanica, andL. multicaulis ×P. juncea hybrids, in which it averaged 7.30 univalents + 6.69 bivalents + 0.096 trivalents and 7.48 univalents + 6.75 bivalents, respectively. The meiotic pairing in the two hybrids indicated that oneL. multicaulis genome was closely homologous with theP. huashanica andP. juncea genomes. BothP. huashanica andP. juncea are possibly donors of oneL. multicaulis genome. Chromosome pairing in theL. secalinus ×L. multicaulis hybrid averaged 4.49 univalents + 11.71 bivalents + 0.02 trivalents, indicating that the genomes ofL. multicaulis andL. secalinus are to some degree homologous. However, they are sufficiently differentiated to insure species distinctness.