Cytogenetic studies in Cochlearia L. (Cruciferae). The origins of C. officinalis L. and C. micacea Marshall

Genome analysis has been used to investigate the evolutionary relationships of the tetraploid species in the genus Cochlearia. The results indicate that both C. officinalis L. (2n=24) and C. micacea Marshal (2n=26) are essentially autotetraploid in origin and that C. scotica Druce is simply a morphological variant of C. officinalis. The chromosomal relationships of the tetraploids to each other and to the diploids in the genus are discussed and the possible routes for the formation of all the species from a single, 2n=12, basic taxon are given. Evidence for the existence of a genic mechanism causing C. officinalis to form only bivalents is given and the mode of evolution of such a mechanism discussed.     

The occurrence and frequency of 2n pollen in three diploid solanums from Northwest Argentina

Summary A group of wild, tuber-bearing species from Northwest Argentina, belonging to the series Tuberosa, Solarium spegazzini Bitt. (spg, 2n=2x=24), S. gourlayi Hawkes (grl, 2n=2x=24 and 2n=4x=48) and S. oplocense Hawkes (opl, 2n=6x=72), and Cuneolata, S. infundibuliforme Phil (ifd, 2n=2x=24), is being used to investigate the mode of origin of polyploids in the genus Solanum. 2n gametes have been detected in the diploid species ifd and spg and in a diploid race of grl, using cytological and breeding approaches. Twenty-two introductions of spg, 8 of grl and 26 of ifd have been tested for 2n pollen; 59%, 63% and 54% of them, respectively, had at least one 2n pollen producing plant. These introductions comprised 238, 76 and 235 plant respectively, of which 20, 16, and 32 plant produced 5% or more 2n pollen. The mechanism of 2n pollen formation was determined in several plant of 2x spg, 2x grl and 2x ifd. All of them were found to form diplandroids via parallel spindles. This mechanism, which gives meiotic products genetically equivalent to first division restitution gametes, is under control of the Mendelian recessive ps. The results suggest that the allele ps is widely distributed in natural populations of the three diploids, and that its frequency is very high. These species are seen as valuable material for population genetic studies, and for the eventual incorporation into a breeding scheme involving sexual polyploidization via 2n gametes.     

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.     

Karyological studies in someHypochoeris spp. (Compositae) from Sicily

FiveHypochoeris spp. from Sicily have been investigated:H. glabra L. (2n=10),H. radicata L. (2n=8),H. cretensis L. (2n=6),H. laevigata L. (2n=12),H. robertia Fiori (2n=8). Basic chromosome numbers are very variable, x = 3, 4, 5, 6. The karyotype of each species is presented. Geographical origin (S. America or Mediterranean region) of the genusHypochoeris and the taxonomic position ofH. robertia are discussed.     

A cytological study ofPelargonium sect.Eumorpha (Geraniaceae)

The chromosome numbers of seven species ofPelargonium sect.Eumorpha have been determined from material of known wild origin, and karyotypic comparisons have been made. Within the section there is variation in basic chromosome number (x = 4, 8, 9, 11), variation in chromosome size, and two species have polyploid races. The three species with chromosome numbers based on x = 11 have the smallest chromosomes (1.0–1.5 µm); chromosomes are larger (1.0–3.0 µm) in the other species.P. elongatum has the lowest chromosome number in the genus (2n = 8).P. alchemilloides is exceptional in that it has four cytotypes, 2n = 16, 18, 34 and 36, and the form with 2n = 36 has large chromosomes (2.0–5.0 µm). Evidence from a synthesized hybrid suggests thatP. alchemilloides with 2n = 16 may be of polyploid origin. The three species based on x = 11 appear to be more closely related to species from other sections ofPelargonium that have the same basic chromosome number and small chromosome size, rather than to other species of sect.Eumorpha.     

New or rare data on chromosome numbers in several taxa of the genus<Emphasis Type="Italic">Artemisia (Asteraceae)</Emphasis> in Poland

Chromosome counts in 16 populations of fiveArtemisia species from Poland are presented in this paper. Those ofA. annua (2n=18) andA. dracunculus (2n=90) are reported for the first time in Polish populations. The decaploid level (2n=90) is described for the first time in non-cultivated populations ofA. dracunculus, and several cases of aneusomaty (intraindividual aneuploid variations in chromosome number: 2n=87, 88 and 89) have been detected in this species. In addition to the already known diploid number (2n=18), the tetraploid level (2n=36) has been detected inA. absinthium. The same two numbers have been recorded inA. abrotanum, which represents the first tetraploid count in populations of this taxon occurring outside botanical gardens. Finally, the chromosome number ofArtemisia campestris subsp.sericea (tetraploid, 2n=36) is reported for the first time. The relevance of polyploidy for the evolution of the genus and other cytotaxonomic or cytobiogeographical aspects are briefly discussed.     

Karyotypic evolution in Gehyra (Gekkonidae: Reptilia) IV. Chromosome change and speciation

Karyotypic data are presented for six additional species from the genus Gehyra collected in Australia, New Guinea and Fiji. C and G-banding of three of the very diverse species which all share the ancestral 2n=44 karyotype, further strengthens the phylogenetic model for the evolution of this complex. With 19 Australian species and chromosome races of Gehyra now karyotyped, it has been possible to evaluate the mode of chromosomal evolution and the role that chromosome change has played in speciation in this genus. It is clear that speciation in certain karyomorph groups has occurred allopatrically, without any gross chromosomal changes. However, in the numerous chromosome races and species which have been involved in colonizing radiations, chromosomal rearrangements have been intricately associated with the speciation process.     

风毛菊属6种植物的核型分析

采用常规压片技术对分布于横断山区菊科(Compositae)风毛菊属(Saussurea DC.)的6种植物进行染色体数目和核型分析。结果表明:尖苞雪莲（S.polycolea var.acutisquama）核型公式为:2n=2x=32=20m+12sm,属2B型;球花雪莲核（S.globosa）型公式为:2n=2x=34=16m+18sm,属2B型;重齿风毛菊(S.katochaete)核型公式为:2n=2x=32=8m+18sm+6st,属3B型;柱茎风毛菊(S.columnaris)核型公式为:2n=2x=32=24m+8sm,属2B型;禾叶风毛菊(S.graminea)核型公式为:2n=2x=28=8m+18sm+2st,属3B型;长毛风毛菊(S.hieracioides)核型公式为:2n=2x=32=12m+16sm+4st,属2B型。6个种染色体中均未发现随体。其中尖苞雪莲和柱茎风毛菊染色体为首次报道。     

The chromosomes of two Drosophila races: Drosophila nasuta nasuta and Drosophila nasuta albomicana V. Introgression and the evolution of new karyotypes

Reciprocal crosses were made between an Indian strain of D. n. nasuta (2n=8) and the Thailand strain of D. n. albomicana (2n=6). Hybrids were fertile. They were inbred for over four years. Later, the karyotypes of the hybrid populations were analysed. In the hybrid progeny of the cross between D. n. nasuta females and D. n. albomicana males, there were six types of kaotypes. Of these, only two types had a diploid content of chromosomes. They were males with 2n=7 and females with 2n= 8 , while others were aneuploids. This hybrid population is designated as Cytorace III. On the other hand, hybrid progeny of the reciprocal cross had 2n-8 in both males and females; and there was no karyotypic variation. This hybrid population is named as Cytorace IV. The composition of these new karyotypes of Cytorace III and IV have been presented and compared with those of Cytorace I and II reported by Ramachandra and Ranganath (1986).     

C-banding patterns in the AustralianBulbine (Liliaceae): The annual group,B. semibarbata s. lato

Chromosome C-band patterns have been studied in 34 populations of the Australian annualBulbine group, which comprises 4x (2n = 26, 28), 8x (2n = 52, 54) and 12x (2n = 78) populations. The 2n = 26B. semibarbata populations have a simple, low heterochromatin pattern with very minor polytypic variation. The 2n = 28 populations, corresponding morphologically to a group given separate status asB. alata, are similar in pattern but exhibit pronounced enhancement of telomeric and, more particularly, centromeric dot bands. NOR heterochromatin and satellites are difficult to identify inB. alata but appear to occur in different positions from the 26-chromosome karyotype. Eastern Australian 8 x patterns are consistent with a proposed hybrid ancestry,B. semibarbata ×B. alata. Annual and perennial C-band profiles in the AustralianBulbine are discussed briefly in relation to the additive and transformation models of heterochromatin evolution and to the possible adaptive significance of variation in heterochromatin content.Cytoevolution in the AustralianBulbine 2; for part 1 see Pl. Syst. Evol.157, 201–217.     

Genetic diversity among Plantagos III. Primary trisomy in Plantago lagopus L.

The paper describes the mode of origin, meiotic behaviour and phenotype of a primary trisomic (2n=12+1) of P. lagopus recovered from an experimental population of disomics. The additional chromosome advances seed germination and flowering.     

Karyological investigations inRanunculus subg.Batrachium (Ranunculaceae) on the Aegean islands

This paper is the first report of an investigation on differentiation and evolutionary pattern inRanunculus subg.Batrachium mainly on the Aegean islands and treats the karyology in the subgenus. The following taxa and chromosome numbers are recorded.R. peltatus subsp.peltatus: 2n = 32, subsp.baudotii: 2n = 32, subsp.saniculifolius: 2n = 16, 32, and 40;R. peltatus s.l.: 2n = 32 and 48;R. penicillatus subsp.pseudofluitans: 2n = 16;R. rionii: 2n = 16;R. sphaerospermus: 2n = 16;R. trichophyllus: 2n = 32, 40, and 48;R. tripartitus: 2n = 48. The karyotypes show certain interspecific differences in chromosome size, in number of chromosome types according to centromere position and in occurrence and position of satellite chromosomes. r-Index and RCL have been calculated.     

Biotypic differences in the karyology ofPennisetum pedicellatum Trin

Detailed karyological analyses have been made of the five biotypes ofPennisetum pedicellatum Trin. These biotypes not only differ in some morphological traits but also in their chromosomal characteristics. Biotype-B with 2n = 48 chromosomes shows constancy, while in the other four 2n = 36 and 64 are found to be “floating”. Other numerical variations include 2n = 42 and 18 chromosomes. Minute karyological differences are not only noted amongst the biotypes, but also there are variations in the complements within a biotype. Such variations are presumed to be buffered through the apomictic mode of reproduction. From the morphological and cytological studies, the possibility of separation of biotype-B from the complex in future has been envisaged.     

Molecular,cytological and morpho-agronomical characterization of hexaploid somatic hybrids in Medicago

Somatic hybrid plants produced by protoplast fusion between tetraploid Medicago sativa (2n= 4x=32) and the diploid species Medicago coerulea (2n= 2x=16) have been RFLP fingerprinted to establish their nuclear composition. Although all of the chromosomes were present, molecular analysis revealed an incomplete incorporation of the alleles of the diploid parent in the fusion products. In the polycross progeny the alleles of both parents segregated in a Mendelian mode. Cytological observations indicated that in the somatic hybrid population minor abnormalities are present; these are restricted mainly to the formation of univalents and lagging chromosomes. Meiosis appeared to be more stable than has been previously reported in the hexaploids of alfalfa. The somatic hybrids grown in the field had a rather vigorous aspect, particularly with respect to the vegetative organs. Forage yield was comparable to that of thmore productive parent. The results are discussed with a view to utilizing the somatic hybrids as starting material for breeding alfalfa at the hexaploid level.This paper was supported by the National Research Council of Italy, Special Project RAISA, Sub-project No.2 paper No. 1911     

Zur Cytotaxonomie vonArabis hirsuta agg. (Cruciferae). IV. Chromosomenzahlen vonA. sagittata (Bertol.) DC. undA. hirsuta (L.)Scop. s. str. aus Europa

Zusammenfassung A. sagittata (Bertol.) DC. von zehn Herkünften aus Europa ist mit 2 n=16 diploid.A. hirsuta (L.)Scop. s. str. einschließlich der sicherlich hierhergehörigen var.glaberrima Wahlenb. von 30 europäischen Herkünften ist mit 2 n=32 tetraploid; diploide Pflanzen konnten beiA. hirsuta s. str. nicht gefunden werden.

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Summary A. sagittata (Bertol.) DC. from 10 different places in Europe has 2 n=16 chromosomes and is diploid.A. hirsuta (L.)Scop. s. str., its var.glaberrima Wahlenb. being included, has been investigated from 30 provenances in Europe, it has the tetraploid chromosome number 2 n=32, diploid plants could not be found in this species.A. hirsuta var.glaberrima (2 n=32) is surely belonging toA. hirsuta s. str. and not toA. allionii (2 n=16).

     

Polyploidy and new chromosome counts in Anaphalis (Asteraceae: Gnaphalieae) from the Qinghai‐Tibet Plateau of China

Abstract Anaphalis is one of the largest genera of the Asian Gnaphalieae (Asteraceae) and is most diversified on the Qinghai‐Tibet Plateau. The chromosome numbers and karyomorphology of six species from seven populations were investigated for the first time for this region. Chromosome numbers have been newly documented for four species: Anaphalis deserti (2n = 56 = 24 median [m]+ 24 submedian [sm]+ 8 acrocentric [st]); Anaphalis plicata (2n = 56 = 26m + 30sm); Anaphalis xylorhiza (2n = 28 = 2 median point [M]+ 14m + 12sm); and Anaphalis rhododactyla (2n = 56 = 32m + 24sm). Two further counts are in agreement with the previously reported numbers, that is, Anaphalis royleana (2n = 28 = 4M + 6m + 18sm) and Anaphalis margaritacea (2n = 28 = 12m + 16sm). A new polyploid cytotype (2n = 56 = 26m + 30sm) was found in the Zougong population of A. margaritacea. Polyploidy is for the first time reported for Anaphalis, with four out of seven counts being tetraploid. Our cytological results suggest that polyploids might have played an important role in the evolution of Anaphalis on the Qinghai‐Tibet Plateau.     

Dati Cariologici Sull'Arisarum Proboscideum (L.) Savi. II

Abstract

Caryological data on «Arisarum proboscideum» (L.) Savi. II. – In specimens of «Arisarum proboscideum» (L.) Savi collected near Acerno (Salerno) two different chromosome numbers – 2n = 28 and 2n = 42 – have been found. In two localities of Tuscany (Consuma, in the upper Valdarno, and San-sepolcro, near Arezzo) only the number 2n = 28 has been found, as it was already reported for Reggello (FABBRI 1966a). Moreover, in regard to the number of female flowers present in each spadix, a greater variability has been observed in the Acerno and Avellino populations (1 – 6 fem. flowers; see FABBRI 1966b) than in the Tuscan ones (1 – 3 fem. flowers); this difference in variability could be possibly connected with the different caryological situation.     

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.     

Investigations on the artificial synthesis of amphidiploids of Brassica tournefortii Gouan with the other elementary species of Brassica. I. Genomic relationships

With the object of studying the genomic relationships of Brassica tournefortii Gouan with the other elementary species of Brassica viz. B. campestris (2n=20, A genome), B. oleracea (2n=18, C genome) and B. nigra (2n=16, B genome), it has been hybridized with them. The percentage of F₁ hybrids formed, their morphology and meiotic behaviour have been described. Based upon crossability relationships and meiotic pairing in the F₁ hybrids, it is inferred that the D genome of B. tournefortii is more closely related to the A genome than to the B and C genomes. It may have been derived from the A genome which likewise shows a strong genetic isolation from B and C. The species has developed a strong genetic barrier in the course of its evolution and shows little crossability, high hybrid sterility and no gene flow with any of the other elementary species. The fact that it has not formed any natural amphidiploids with the elementary species which otherwise are formed in all combinations, is more evidence that it originated more recently than the A genome. It is presumed that B. tournefortii, being more distantly related to B. nigra than to other elementary species, may form stable artificial aphid resistant amphidiploids with the former.     

Bemerkungen zur Karyologie und Systematik einiger Sippen der Gattung Vicia L

Continuing the earlier investigations of Vicia species, karyologically not examined hithero, the following taxa of th genus have been described:

• 1 Chromosome numbers reported for the first time–V. Meyeri Boiss. (2n = 14), V. pubescens (DC.) Link (2n = 14), V. graminea SM (2n = 14), V. ramuliflora (MAXIM .) OHWI (2n = 28), V. semiglabra RUPR . ex BOISS . ssp. caucasica (EKVTIM .) RADZHI (2n = 10), V. semenovii (RGL . et HERD .) FEDTSCH . (2n = 12), V. costata LDB (2n = 12), V. hajastana GROSSH . (2n = 10).
• 2 Re-investigations – V. tenuissima (M. BIEB .) SCHINZ et THELL . (2n = 14), V. benghalensis L. (2n = 14), V. lathyroides L. (2n = 12).

Brief cytological and systematical remarks are given for all the species mentioned above. Discrepancies in the literature are especially discussed (V. benghalensis, V. peregrina, V. lathyroides). Our data support the uniformity of the subgen. Ervum in regard to chromosome number (2n = 14) and primitivity of the karyotype. The finding of an advanced karyotype with 10 chromosomes (V. semiglabra) within the subgen. Cracca has been recorded for the first time. In this group a new polyploid taxon (V. ramuliflora) has been found too. The known polyploid representatives of the genus are summarized, all of which belong to perennial species of the subgen. Cracca. Most of the taxa are characterized by obviously distinct karyotypes, that is partly ture for chromosome sizes too (conspicuously long: V. hajastana, V peregrina; conspicuously shrt: V. ramuliflora, V. lathyrodies). This striking karyological differentiation seems to refer not only to the Old world species but also to the New world ones, of which V. graminea (and a strain named „V. selloi”︁) has been examined for the first time. In general the chromosome number and structure (besides the traditional morphological characters) have been proved as extremely valuable for taxonomical considerations within the genus. This is a common situation in many other plant groups too. We therefore think of further cytotaxonomical studies as especially suitable for explaning the evolution and the evolutionary mechanisms within the genus.