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1.
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.
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2.
The new genusCaucasalia is described. Four species are included, previously referred toSenecio, Cacalia, Cineraria, Pojarkovia orAdenostyles. The latter genus may be the closest relative, being similar in habit and chromosome number, but different in floret colour and style morphology. The new genus is centered in the Caucasus mountains, with extensions into Anatolia.Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday  相似文献   

3.
Pelargonium caroli-henrici spec. nova (sect.Hoarea) is described. The new species is apparently endemic to quartzite areas of Vanrhynsdorp Division in the western Cape Province (South Africa). The chromosome number 2n = 22 was counted on specimens in cultivation.Dedicated to Prof.K. H. Rechinger on the occasion of his 80th birthday.  相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
The present communication deals with the observations made on the morphology, reproduction and cytology ofUlothrix zonata (Weber & Mohr)Kütz. in culture. The alga displays a remarkable phenotypic plasticity in nature as well as in culture. The present study provides additional evidence of karyology in support ofLokhorst andVroman's treatment ofU. zonata which merges a number of earlier described species in it. The cytological details and chromosome number (n = 10) determined for the Indian isolates ofU. zonata agree with those ofSarma for the British material.NBRI Research Publication No. 63 (N.S.)  相似文献   

7.
The subspecies ofAustralopithecus africanus Dart, 1925 have been revised in a morphological and statistical analysis. Four subspecific names were previously proposed, but only one was found to be valid. The subspeciesA. africanus transvaalensis (Broom, 1936), from the Plio/Pleistocene of South Africa, cannot be sustained due to an insufficient sample, and is combined with the nominate race,A. a. africanus. The type ofA. africanus afarensis Tobias, 1980 is a mistake in identification and notA. africanus, but a pongid. The population ofA. africanus from the late Pliocene of Ethiopia does indeed represent a relatively small-toothed geographical race for which the nameA. africanus aethiopicus was conditionally proposed; and the lectotype for it, A.L. 288-1, is notA. africanus, but the type ofHomo antiquus Ferguson, 1984. The trinominalaethiopicus is thus unavailable for the Ethiopian race, which is redescribed as a new subspecies,A. africanus miodentatus n. ssp., and the mandible A.L. 266-1 is designated as the holotype.  相似文献   

8.
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.  相似文献   

9.
Morphological and cytological investigations as well as crossing experiments were carried out withRanunculus seguieri Vill. and 4 species of theRanunculus alpestris L. group (R. alpestris L.,R. traunfellneri Hoppe,R. bilobus Bertol.,R. crenatus Waldst. & Kit.). ForR. seguieri andR. alpestris, localities and distribution are given in addition to extensive diagnoses. A key to the species includes morphological characteristics and distribution data forR. traunfellneri, R. bilobus, andR. crenatus. New diagnostic characters are described. Crossing experiments betweenR. seguieri and the species of theR. alpestris group were unsuccessful. All 5 species have a chromosome number of 2n = 16, the record forR. bilobus is new. There is no statistically significant difference between the karyotypes ofR. seguieri andR. alpestris s. str. Nevertheless, according to morphological evidence and crossing experiments,R. seguieri is not closely related to theR. alpestris group.
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10.
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.  相似文献   

11.
The biosystematics of theFestuca violacea group (F. rubra subsp.violacea sensuHackel) in the Eastern Alps is studied.F. picturata Pils (=F. picta Kit. exSchultes nonJ. F. Gmelin) is confirmed as diploid, whereas the chromosome numbers forF. nitida (diploid),F. puccinellii (hexaploid), andF. norica (diploid, tetraploid and hexaploid) are reported for the first time. Details of morphology, leaf anatomy, and epidermal structures now allow a better separation of these species; new maps illustrate their distribution. Karyological, chorological, morphological, and anatomical data form the basis for a discussion of the phylogeny of theF. violacea group and its position withinF. rubra s. latiss.
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12.
A new triploid microspecies ofTaraxacum from sect.Erythrocarpa is described:Taraxacum erzincanense Doll. In addition, 2x 3x, and 4x chromosome numbers, pollen conditions and chorological facts are reported for serveral other rare Oriental microspecies.
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13.
Morphological and cytological investigations as well as crossing experiments were carried out with the 5 species of theRanunculus alpestris group (R. alpestris L.,R. traunfellneri Hoppe,R. bilobus Bertol.,R. crenatus Waldst. etKit.,R. magellensis Ten.). A key to the species is presented; localities and distribution are given in addition to extensive diagnoses. Crossing experiments between the 5 taxa were successful (F1-F3 individuals, backcross types, tripeland quadrupelbastards); the morphology of the experimentally obtained F1-hybrids was mostly intermediate. All 5 species as well as all hybrids have a chromosome number of 2n = 16; there is no statistically significant difference between the karyotypes of the 5 taxa. According to the results of the morphological investigations and the crossing experiments we can distinguish 2 subunits of very closely related species: a)R. alpestris, R. traunfellneri, R. bilobus; b)R. crenatus, R. magellensis. The speciation within the group ofRanunculus alpestris is discussed.
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14.
Chromosome arrangement in interphase has been inferred from an analysis of the relative positions of the chromosomes and the chromosome arms in untreated haploid pollen grain metaphases ofUvularia grandiflora. The distances between centromeres forming the smallest possible circle were measured in 43 metaphases. The relative positions of the chromosomes did not differ significantly from randomness. Neither did similar-sized chromosome arms show any tendency to be next to each other. The results thus disagree both with the hypothesis ofComings (1968) that each chromosome occupies a definite position in the interphase nucleus and with the claim ofBennett (1982) that similar-sized chromosome arms lie next to each other.  相似文献   

15.
A cytological analysis of 22 experimental interspecific hybrids withinEpilobium sect.Epilobium, involving 15 taxa, has indicated that the generalized western North AmericaE. obcordatum has the BB chromosome arrangement. This strengthens greatly our earlier contention that BB is the original chromosome arrangement in the section. The very distinctive northwestern North AmericanE. luteum, only species in the section with cream-colored petals, has the CC arrangement, like the members ofHaussknecht'sAlpinae. This chromosome arrangement apparently originated in the North Pacific region in plants that were of normal stature. The North AmericanE. leptocarpum, which closely resembles the Japanese endemicE. fauriei and, like it, forms gemmae in the axils of the upper leaves, also resembles it in having the CC chromosome arrangement. The AsianE. platystigmatosum has a novel chromosome arrangement derived from BB, which we here designate the EE arrangement.  相似文献   

16.
Rhabdodendron macrophyllum (Spruce ex Benth.)Huber andR. amazonicum (Spruce exBenth.)Huber differ in several anatomical and morphological characters (secretory cavities, hypoderm, peltate hairs, internodal region and petiole). A position of the monotypicRhabdodendronaceae in theCentrospermae as recently suggested is hardly supported: Peltate hairs, lysigenous secretory cavities and spicular cells in the leaves, multilacunar nodes, chromosome number (R. macrophyllum: n = 10; first count for the genus resp. family), ± simultaneous (or slightly centripetal) development of the androeceum, anacrostyly and two ovules in the unicarpellate gynoeceum, apparent disc, monotelic racemes, and data available from literature (pollen, sieve tube plastids) clearly indicate a close affinity toRutaceae, and even make the family rank ofRhabdodendron questionable.  相似文献   

17.
Cypripedioideae (Orchidaceae) have been the subject of numerous taxonomic treatments with conflicting interpretations of relationships among the five genera and the 150–170 species. We have produced nuclear ribosomal ITS nucleotide sequences for nearly 100 slipper orchid species and used parsimony analysis to investigate their relationships. Our results demonstrate that each genus, as currently circumscribed, is monophyletic (Mexipedium andSelenipedium being represented by a single taxon). LikerbcL data, ITS sequences placeMexipedium sister toPhragmipedium. Relationships at the sectional level inPaphiopedilum are largely as described byCribb. However, the division ofPaphiopedilum into subgg.Brachypetalum andPaphiopedilum is not supported; subg.Brachypetalum is paraphyletic to subg.Paphiopedilum. Phragmipedium species are divided into the same three major clades as in the taxonomic scheme ofMcCook. The plicate-leaved genera,Cypripedium andSelenipedium, are successive sister groups to the rest of the subfamily, confirming generally held opinions that they display plesiomorphic characters compared to the conduplicate-leaved genera. A survey of karyotypes in the context of the ITS tree reveals a general trend toward increased chromosome number, probably brought about by centric fission. These data also accord with a previously suggested biogeographic hypothesis of a widespread Northern Hemisphere distribution, followed by range fragmentation due to Miocene cooling.  相似文献   

18.
First generic chromosome counts reveal the base number x=7 for the generaTetrameranthus andRollinia. T. umbellatus from the Peruvian Amazon is diploid (2n=14),T. duckei from Brazil (Manaus) is tetraploid (2n=28). In the NeotropicsRollinia (7 species counted) has developed diploid to octoploid taxa (2n=14, 28, 42, 56). Counts of 7 South AmericanAnnona species are presented for comparison (2n=14, 28). The West AfricanCleistopholis patens has 2n=14. The Asian genusMezettia: 2n=14 and the neotropicalGuatteria tribe: 2n=28 are also revised. A detailed karyomorphological comparison, including karyotypes, banding patterns, condensing behaviour of chromosomes and structure of interphase nuclei reveals that the closely related generaAnnona andRollinia are almost identical in their diploid genomes, whereas the polyploid ones differ in their heterochromatin (=hc) composition and number of NO-chromosomes.Cleistopholis, Mezettia and theGuatteria tribe are karyologically and systematically distinct from each other and fromAnnona/Rollinia. Tetrameranthus as compared with the karyomorphology of about 60 other Annonaceous genera has a very peculiar and unusual karyomorphology which underlines its isolated position. Nuclear structures are almost identical in the African genusUvariopsis (2n = 16) and partly similar in theGuatteria tribe; both also share some morphological similarities and possibly are related. From a comparison ofTetrameranthus with several nuclear types within theMagnoliidae, a new model of chromosome evolution in primitive Angiosperms is suggested. In respect to their eco-morphological differentiation the genera investigated differ strongly from each other.Dedicated to Prof. Dr. K.-H.Rechinger on the occasion of His 80th birthday.  相似文献   

19.
A review of current knowledge of chromosome numbers and modes of reproduction in the genusRubus L. is presented. Chromosome numbers from some species of subg.Malachobatus Focke together with results of crossing experiments are reported for the first time.  相似文献   

20.
The five annual species ofAdonis L., sect.Adonis, growing in Israel, form a series of diploid, tetraploid and hexaploid species. Their somatic chromosome numbers are 2n = 16 inA. annua L.,A. dentata Del. andA. palaestina Boiss., 2n = 32 inA. microcarpa DC., 2n = 48 inA. aestivalis L.; counts forA. dentata, A. palaestina andA. microcarpa are new records. There are indications that alloploidization may have been involved in the process of speciation in sect.Adonis. A taxonomic survey of the 8 species of the section reveals that a higher ploidy level is usually combined with a larger distribution area.  相似文献   

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