Étude cytotaxinomique de quelquesDipsacaceae d'Iran

Chromosome numbers for 28 Iranian populations ofDipsacaceae, corresponding to 14 taxa, are presented. New are those forScabiosa aff.olivieri var.pinnatisecta, S. persica, Pterocephalus canus, P. kurdicus, Dipsacus strigosus, Cephalaria dichaetophora, C. hirsuta, C. microcephala, C. subindivisa andC. aff.sublanata. Except forC. syriaca (x = 5) andC. dichaetophora (x = 7 : new basic chromosome number forCephalaria), all species examined are characterized by the basic chromosome number (x = 9). Instances of aneusomaty, B-chromosomes, aneuploidy, dysploidy, and polyploidy have also been found.

     

Molecular phylogeny of the genus<Emphasis Type="Italic">Hypericum</Emphasis> (Hypericaceae) from Korea and Japan: evidence from nuclear rDNA ITS sequence data

As part of our ongoing phylogenetic study of genusHypericum, nuclear ribosomal DNA internal transcribed spacer sequences were analyzed for 36 species ofHypericum as ingroup and two species ofThornea as outgroup. This sampling included most of the previously described species from both Korea and Japan. The ITS phylogeny suggested that the surveyedHypericum species belong to a monophyletic section,Trigynobrathys, and a polyphyletic section,Hypericum. In addition, two monotypic sections,Sampsonia andRoscyna, were identified. Members of sectionHypericum occur in four different lineages worldwide, which imply at least four independent origins. The Korean and Japanese species of sectionHypericum form a monophyletic group, except forH. vulcanicum. Instead, that particular species belongs to a distinct monophyletic group withH. scoreri andH. formosa from other geographic areas, and is a sister to sectionTrigynobrathys. The Korean and Japanese species of sectionTrigynobrathys show a monophyletic origin.H. sampsonii is now recognized as a distinct section rather than being a member of sectionsHypericum orDrosocarpium, as had been indicated previously. Our results differ somewhat from those of recent morphological and cytological studies. The phylogenetic relationships among Korean and Japanese species have now been mostly resolved via ITS phylogeny.     

Experimental analyses of the evolutionary processes inTrillium

In the Japanese species ofTrillium examined here, every interspecific cross produced healthy F₁ progeny at the rate of about 50 to 60 per cent of the total inborn ovules except forT. hagae. These figures were not appreciably different from those of self-pollinated or sib-mated examples of these species.Trillium hagae, a putative natural hybrid betweenT. kamtschaticum (2n=10) andT. tschonoskii (2n=20), accepted all foreign sources of pollen grains in manual pollination. These and other crossing experiments suggest that no appreciable barrier has developed that might cause interspecific crossability and that they are habitual inbreeders. Despite theri crossability, a very low rate of actual pollen flow was detected by examining electrophoretic phenotypes of seeds taken from sympatric populations of these species.     

Karyology of theScorzonera (Compositae) species from the Iberian Peninsula

A karyological study of 15 taxa ofScorzonera L. from the Iberian Peninsula has been made. The chromosome numbers found inS. hispanica var.pinnatifida, S. baetica, S. reverchonii, S. angustifolia, S. laciniata var.calcitrapifolia and var.subulata (2n = 14) are new. Diploid cytotypes with 2n = 14 and 2n = 12 prevail, andS. hispanica var.crispatula is the only taxon which exhibits autopolyploidy (2n = 14, 28). x = 7 is considered to be the base chromosome number within the genus, with x = 6 being derived from it by translocation. This and detailed karyotype analyses allow to group the Iberian Peninsula species ofScorzonera into three groups.     

Chromosomal evolution withinPiperaceae

Chromosome numbers for 26 different species of the generaPiper, Peperomia andPothomorphe (Piperaceae) are reported. The basic chromosome numbers are 2n = 26, x = 13 (Piper, Pothomorphe) and 2n = 22, x = 11 (Peperomia), polyploid series are characteristic forPiper andPeperomia. Piper has the smallest chromosomes and prochromosomal interphase nuclei,Peperomia the largest ones and mostly reticulate to euchromatic nuclei.Pothomorphe is intermediate in both characters. The karyomorphological differences betweenPothomorphe andPiper underline their generic separation. Interspecific size variation of chromosomes occurs inPiper andPeperomia. Infraspecific polyploidy was observed inPiper betle. C-banding reveals different patterns of heterochromatin (hc) distribution between the genera investigated. The genome evolution is discussed.     

Variation and geographical distribution of ploidy levels inPennisetum sectionBrevivalvula (Poaceae) in Burkina Faso,Benin and southern Niger

Pennisetum sect.Brevivalvula is a species complex characterized by polyploidy and apomixis. Ploidy level was assessed by DAPI-flow cytometry for 304 plants of the section, originating from Burkina Faso, Benin and southern Niger. The results were confirmed for 54 plants based on chromosome counts. The samples show four euploidy levels (with x = 9) distributed among five species:P. hordeoides (2n = 36, 54),P. pedicellatum (2n = 36, 45, 54),P. polystachion (2n = 18, 36, 45, 54),P. setosum (2n = 54), andP. subangustum (2n = 18, 36, 54). The geographical distribution of these ploidy levels seems related to major vegetation zones present in Africa. Diploid populations ofP. polystachion andP. subangustum were found in the Banfora area, in Burkina Faso.     

Karyological studies onGentiana sect.Chondrophyllae (Gentianaceae) from China

Nineteen populations of fifteen species ofGentiana sect.Chondrophyllae from China were observed cytologically.Gentiana alsinoides, G. anisostemon, G. asterocalyx, G. exigua, G. heterostemon, G. intricata, G. praticola, G. pseudoaquatica, G. spathulifolia, andG. subintricata all had the same chromosome number of 2n = 20 (or n = 10), whereasG. piasezkii had 2n = 36,G. squarrosa 2n = 38,G. prattii 2n = 18,G. aristata 2n = 14 (n = 7), andG. heleonastes 2n = 12. All these chromosome numbers are documented here for the first time, except forG. squarrosa, where it is a new number report. The basic numbers of x = 6, x = 7 and x = 19 are new for the section. Karyotype analyses of some species revealed that, except for a few cases, the species examined mainly had metacentric chromosomes. 2n = 20 = 2m(SAT) + 18m was found to be the main type of karyotype for the species with 2n = 20. Chromosomal evolution and its mechanism in this section are also discussed.     

Variations in total phenolics during ontogenetic, morphogenetic, and diurnal cycles inHypericum species from Turkey

Several species ofHypericum are used in traditional Turkish folk medicine. Their most medicinally important secondary metabolites are the hypericins, hyperforins, and phenolics. Here, we determined the ontogenetic, morphogenetic, and diurnal variations in total phenolics contents fromH. aviculariifolium subsp.depilatum var.depilatum (endemic),H. perforation, andH. pruinatum. Plants of wild-growingH. aviculariifolium subsp.depilatum var.depilatum andH. perforatum, and greenhouse-grownH. pruinatum were harvested four times per day during their vegetative, floral-budding, full-flowering, fresh-fruiting, and mature-fruiting stages. They were then dissected into stem, leaf, and reproductive tissues to be dried separately and assayed. The highest level of phenolics inH. aviculariifolium subsp.depilatum var.depilatum andH. pruinatum was found in the leaves, whereas the floral buds produced the greatest amount inH. perforatum. Variations in contents from whole plants fluctuated diurnally, differing among species over the course of ontogenesis, reaching the highest level at floral-budding and tending to increase at mid-day inH. aviculariifolium subsp.depilatum var.depilatum. ForH. perforatum andH. pruinatum, contents also were the highest during floral development, although no diurnal fluctuations were observed in those species.     

Chromosome numbers of European blackberries (Rubus subg.Rubus,Rosaceae)

Chromosome numbers are presented for 32 collections of 29 European blackberry species (Rubus subg.Rubus) from Germany. One species is triploid (2n = 21), 27 species are tetraploid, (2n = 28), and one species is pentaploid (2n = 35). Chromosome numbers are reported for the first time ofR. adspersus, R. amisiensis, R. calvus, R. conothyrsoides, R. contractipes, R. demissus, R. elegantispinosus, R. ferocior, R. foliosus, R. hypomalacus, R. leucandrus, R. nemorosus, R. platyacanthus, R. praecox, R. rhombifolius, andR. rhytidophyllus. Chromosome numbers forR. dasyphyllus, R. gelertii, R. glandithyrsos, R. lamprocaulos, R. lindebergii, R. macrophyllus, R. montanus, R. muenteri, R. pedemontanus, R. polyanthemus, R. senticosus, R. silvaticus, andR. vigorosus are confirmed.     

Chromosomal evolution ofGentiana andJaeschkea (Gentianaceae), with further documentation of chromosome data for 35 species from western China

Chromosome numbers were recorded for 63 populations of 34 species belonging to the genusGentiana from the high altitude regions of western China. Counts for 22 species were reported for the first time and new numbers were found forG. heleonastes (2n = 36),G. prattii (2n = 20) andG. pseudoaquatica (2n = 40). Incorporating previous data, a complete series of gametic chromosome numbers from n = 6 to 24 and 26 was established for the genus, suggesting rapid karyotypic evolution by a combination of dysploidy and polyploidy. The cytotype 2n = 20 is proposed as the ancestral type in sect.Chondrophyllae s. l. The chromosome number 2n = 16 was found forJaeschkea microsperma for the first time which, with previous reports of 2n = 18, 20 and 22, indicates thatJaeschkea is a typically dysploid genus.     

Chemical Constituents of Some<Emphasis Type="Italic">Hypericum</Emphasis> Species Growing in Turkey

The present study was conducted to determine the content of pharmacologically important constituents hypericin, pseudohypericin, chlorogenic acid, rutin, hyperoside, apigenin-7-O-glucoside, quercitrin, quercetin and vitexin in eightHypericum species namely,H. aviculariifolium Jaup. and Spach subsp.depilatum (Freyn and Bornm.) Robson var.depilatum (endemic),H. lydium Boiss.,H. montbretii Spach,H. orientale L,H. origanifolium Willd,H. perfoliatum L,H. perforatum L. andH. pruinatum Boiss. and Bal. growing in different locations of Turkey. Wild growing plants were harvested at flowering and after dried subsequently assayed for the constituents by HPLC method. Hyperoside, quercitrin and pseudohypericin were found in all species. Hypericin, quercetin and chlorogenic acid were also detected in all species with the exceptions ofH. orientale for hypericin,H. montbretii for quercetin andH. lydium for chlorogenic acid. Apigenin-7-O-glucoside accumulation was observed in all examined species at various levels, except forH. orientale andH. origanifolium. Rutin was detected inH. aviculariifolium,H. lydium, H. orientale, H. perfoliatum andH. perforatum. On the contrary of the other species, vitexin was found in onlyH. motbretii. The presence of flavonoid vitexin in the genusHypericum was reported for the first time.     

Karyology and systematics of the genusAmbavia and otherAnnonaceae from Madagascar

New chromosome counts and nuclei structures are reported forAnnonaceae species from Madagascar:Ambavia (2n = 14),Xylopia (2n = 16) andPolyalthia (2n = 18). This first generic count ofAmbavia and its nucleotypic parameters underline its long term isolation from the African continent and it should be regarded as an extremely distinct member of the basic stock of AfricanAnnonaceae. Some karyological similarities are found with the African generaCleistopholis (2n = 14) andUvariopsis (2n = 16) and the AmericanTetrameranthus (2n = 14, 28). The karyology ofXylopia is completely in line with previous results from the Palaeo- and Neotropics.Polyalthia has 2n = 18, and x = 9, probably the only base number within the whole genus. Fluorochrome and Giemsa-C-band patterns are identical with different congeneric species.Dedicated to Prof. DrElisabeth Tschermak-Woess on the occasion of her 70th birthday.     

Evolution alpiner Populationen vonEuphrasia (Scrophulariaceae): Chromosomenzählungen an diploiden und polyploiden Sippen aus den Ostalpen

Chromosome counts are reported for several E. Alpine taxa ofEuphrasia sect.Euphrasia. First records of diploidy for small-flowered taxa are 2n = 22 forE. inopinata andE. sinuata, related toE. minima (4 x). Aberrant E. AlpineE. hirtella is 2 x, just as the typical W. Alpine populations of this species. Tetraploidy, 2n = 44, has been found inE. pumila, close toE. stricta (also 4 x). The limitation of ploidy levels within sect.Euphrasia to 2 x and 4 x on the chromosome base number x = 11 is confirmed.

     

Chromosome numbers of the genusCalamagrostis in Japan

Chromosome counts for 783 collection ofCalamagrostis in Japan are reported. These include the first record forC. tashiroi and the reports of new cytotypes inC. stricta, C. hakonensis andC. longiseta. The geographical distribution of different cytotypes ofC. langsdorffii andC. hakonensis is outlined. Counts are also reported for a number of “intermediates” which are supposed to be interspecific hybrids or hybrid derivatives. A summary of chromosome counts for JapaneseCalamagrostis so far recorded is tabulated. No diploid plants with 2n=14 chromosomes are found. The tetraploid taxa, which are plentiful and seem to have adaptively radiated in Japan, jack any sign suggestive of their recent origin from the diploids. It is suggested that plant with 2n=28 (4X in the traditional sense) may be regarded as semidiploid and having that behavior, and that speciation ofCalamagrostis in Japan has occurred principally at this chromosome level. Speciation by means of amphiploidy may have been scarce. It is also suggested that hybridization and polyploidy have greatly contributed to the formation of complicated internal structure of various species.     

High molecular weight glutenin subunit variation in wild and cultivated einkorn wheats (Triticum spp.,Poaceae)

Variation in high molecular weight (HMW) glutenin subunit composition among wild and cultivated einkorn wheats (2n = 2x = 14, AA) was investigated using one- (SDS-PAGE and urea/SDS-PAGE) and two-dimensional (IEF × SDS-PAGE) electrophoretic analyses. The material comprised 150 accessions ofTriticum urartu, 160 accessions ofT. boeoticum, 24 accessions ofT. boeoticum subsp.thaoudar and 74 accessions of primitive domesticatedT. monococcum from many different germplasm collections. The biochemical characteristics of HMW-glutenin subunits ofT. boeoticum andT. monococcum were highly similar to one another but distinctly different from those ofT. urartu. All the species analysed were characterised by large intraspecific variation and only three HMW-glutenin subunit patterns were identical betweenT. boeoticum andT. monococcum. Consistent with the distinct nature ofT. urartu, all its HMW-glutenin patterns were different from those found inT. boeoticum andT. monococcum. The differences detected between these species might reflect their reproductive isolation and are consistent with recent nomenclatural and biosystematic treatments that recogniseT. urartu as separate species fromT. boeoticum andT. monococcum. The presence of three distinct glutenin components in some accessions of the species studied seems to be evidence for the existence of at least three active genes controlling the synthesis of the HMW-glutenin subunits in the A genome of wild and primitive domesticated diploid wheats. Results indicate also that HMW-glutenin subunits could represent useful markers for the evaluation of genetic variability present in different wild diploid wheat collections and subsequently for their conservation and future utilisation.     

Cytotaxonomic study of genusHymenasplenium (Aspleniaceae) in Xishuangbanna, Southwestern China

The gametic chromosome numbers of sevenHymenasplenium (Aspleniaceae) species from Xishuangbanna, Yunnan Prov., China, were investigated. All the examined individuals ofH. obscurum, H. cheilosorum andH. latipinnum were sexual diploids with n=39 chromosomes. Intraspecific cytological variation was found inH. excisum, which has a sexual diploid (n=39) and a tetraploid (n=78). Only a triploid apogamous cytotype (n=ca.117) was found inH. laterepens. Hymenasplenium apogamum showed the most complicated intraspecific variation and included a sexual diploid (n=39), a sexual tetraploid (n=78) and an apogamous triploid (n=ca.117). This work reports for the first time the sexual diploids ofH. cheilosorum andH. apogamum, which are only apogamous elsewhere in east Asia, Himalayas and Indochina. These results may indicate that this area is one of the diversity centers ofHymenasplenium. Most of the above species have chromosome numbers based on x=39. In contrast,H. costarisorum contains a sexual diploid (n=36) and a sexual tetraploid (n=72), indicating that its basic number is x=36.     

Comparative karyomorphology and interrelationships ofSelaginella in Japan

Karyomorphological comparisons were made of 16 native and cultivated species ofSelaginella in Japan. The somatic chromosome numbers are 2n=16 inS. boninensis; 2n=18 inS. doederleinii, S. helvetica, S. limbata, S. lutchuensis, S. nipponica, S. selaginoides, S. tama-montana, andS. uncinata; 2n=20 inS. biformis, S. involvens, S. moellendorffii, S. remotifolia, andS. tamariscina; 2n=30 inS. rossii; and 2n=32 inS. heterostachys. The interphase nuclei of all species examined are uniformly assigned to the simple chromocenter type. The metaphase karyotype of 2n=16 (x=8) is 8 m (=median centromeric chromosomes)+8(st+t)(=subterminal and terminal). The group of the species having 2n=18 (x=9) is heterogeneous karyomorphologically: The karyotype ofS. nipponica is 2n=18=6 m+12(st+t),S. tama-montana 10 m+2 sm(=submedian)+6(st+t), andS. uncinata 6 m+7 sm+5(st+t). Although the remaining five species have the common karyotype 8 m+4 sm+6(st+t), the values of mean chromosome length are variable. Another group of the specles having 2n=20 (x=10) is homogeneous, since all species have the same karyotypes 8 m+4 sm+8(st+t) and have similar chromosome size. The karyotype of 2n=30 is 12 m+6 sm+12(st+t) and is suggested to be a triploid of x=10, and 2n=32=16m+16(st+t), a tetraploid of x=8. Thus, three kinds of basic chromosome numbers, x=8, 9, 10 are present in JapaneseSelaginella examined, and their karyomorphological relationships are discussed.     

Seedling establishment ofPolygonum cuspidatum andPolygonum weyrichii var.alpinum at high altitudes of Mt Fuji

Seedling establishment ofPolygonum cuspidatum (Seib. et Zucc.) andPolygonum weyrichii (F. Schmit) var.alpinum (Maxim.), dominant early-successional species in a volcanic gravel area on Mt Fuji, Japan, was compared for current-year seedlings at 2500 m a.s.l. The rate of survival in the first winter after germination at 2500 m was 2% and 24% forP. cuspidatum andP. weyrichii seedlings, respectively, and correlated with the upper distribution limit of each (2500–2600 m forP. cuspidatum; 3200–3300 m forP. weyrichii). The critical size for survival was 12 mg dry weight for overwintering current-year seedlings of both species. At 2500 m, the percentage of seedlings that attained the critical size for survival at the end of the first growing season was 19% and 85% forP. cuspidatum andP. weyrichii, respectively. Growth curves indicated that the larger-seeded characteristic ofP. weyrichii contributed to larger end-of-season size and resulted in higher rate of seedling survival at 2500 m, compared with smaller-seededP. cuspidatum. Current-year seedlings ofP. weyrichii, at least up to 3250 m, attained the first year annual growth critical for overwintering and therefore for successful seedling establishment, due to the large-seeded characteristic. At the top (3770 m) beyond the upper distribution limit ofP. weyrichii, most seedlings raised artificially failed to attain the critical size for survival in the first growing period due to the reduced growing period. Failure of seedling establishment would thus appear to restrict the distribution of the species at altitudes higher than 3300 m.     

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.