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Polyploidy distribution and variations of karyotypes in Allium grayi Regel were examined in 7 natural populations in Okayama Prefecture, Japan. They showed often tetraploid (2n =32) and pentaploid (2n=40) plants together in the 5 populations and hexaploid (2n=48) plants in the Kasaoka population. The hexaploid plant of the species was found for the first time in western-half part of Japan. Tetraploid plants were solely observed in the Oku population and only pentaploid plants were found in the Kuse population. The analysis revealed the presence of the 2 major different karyotypes : One type consisted of only median- and submedian-centromeric chromosomes and the other type consisted of subterminal-centromeric chromosome (s) in addition to median- and submedian-centromeric chromosomes.

Chromosome numbers of all vascular plant species and varieties growing in the area covered by Flora Palaestina, and of which the karyology was investigated, are given. The plants collected for examination were examined either directly, or were the result of crosses (natural as well as artificial) between wild, or cultivated and wild, forms. Special cytological features concerning chromosomes’ structure (e.g.,holocentric, extreme size) or behavior (e.g., disturbed meiosis, asynapsis) are also reviewed.

New chromosome numbers of seven peanut species, A. cryptopotamica Krapov. and W.C. Gregory and A. douradiana Krapov. and W.C. Gregory (Sect.Erectoides), A. subcoriacea Krapov. and W.C. Gregory and A chiquitana Krapov.,W.C. Gregory and C.A. Simpson (Sect. Procumbentes), A. cruziana Krapov., W.C.Gregory and C.A. Simpson, A. Herzogii Krapov., W.C. Gregory&C.A. Simpson and A. Simpsonii Krapov. and W.C. Gregory (Sect. Arachis) have been determined,all of them have 2n=20. SAT chromosomes were analysed for all species and a new type of satellited chromosome was described for the genus, which was named 3B for its close resemblance to the first described 3 type. “A” chromosomes were only found in A. Herzogii, A. Simpsonii and A. chiquitana from all the studied species. The last one belong to the section Procumbentes, however, the type of satellited chromosome and the presence of “A” chromosomes in its karyotype suggest that it should be moved from section Procumbentes. The presence of "A" chromosomes prov...

Foram analisadas 33 espécies, entre nativas e introduzidas, pertencentes a 20 famílias de angiospermas ocorrentes no Estado de Pernambuco. A caracterização cariotípica da maioria das espécies foi baseada no número e morfologia cromossômica, padrão de condensação de cromossomos profásicos e estrutura de núcleo interfásico. Cinco espécies tiveram seus números cromossômicos determinados pela primeira vez, sendo elas: Cereus jamacaru (2n=22), Clitoria fairchildiana (2n=22), Eugenia luschnathiana (2n=22), Licania tomentosa (2n=22) e Spondias tuberosa (n=16). No caso de Licania tomentosa esta é a primeira citação de número cromossômico para o gênero. Das outras 28 espécies, três (Cecropia cf. palmata, 2n=26; Crinum erubescens, 2n=70; e Schinus terebentifolius, 2n=28) apresentaram números cromossômicos diferentes dos registrados previamente na literatura. Thirty three native and introduced species from 20 families of angiosperms collected in the State of Pernambuco were analysed. The karyotype description of the majority of the species was based on chromosome number and morphology, condensation pattern of prophase chromosomes as well as interphase nuclear structure. In five species (Cereus jamacaru, 2n=22; Clitoria fairchildiana, 2n=22; Eugenia luschnathiana, 2n=22; Licania tomentosa, 2n=22; and Spondias tuberosa, n=16) the chromosome number is reported here for the first time. In the case of Licania tomentosa, this is also the first report for the genus. Among the other 28 species, three (Cecropia cf. palmata, 2n=26; Crinum erubescens, 2n=70; and Schinus terebentifolius, 2n=28) showed chromosome numbers different from what has previously been reported.

A number of interchanges (>100) were induced with the help of gamma rays in a lentil cultivar (PL 639). Trisomics were also available in the progeny of one interchange heterozygote (T35); these were found to be trisomic for one of the two chromosomes involved in the interchange. For the identification and isolation of interchange homozygotes from the progeny of each interchange heterozygote, several progeny plants exhibiting 7 bivalents were crossed to normal plants. The resulting hybrids showing an association of 4 chromosomes were marked and their parental lines (that were progeny of interchange heterozygotes) were identified as interchange homozygotes. By using this approach, 15 interchange homozygotes were isolated. For the purpose of assembly of an interchange tester set, chromosomes involved in each of a number of interchanges were identified through intercrossing and karyotype analysis. 7 of the above 15 interchange homozygotes were subjected to intercrossing followed by meiotic analysis of hybrids. These 7 interchange stocks could be arranged in following three groups : (i) A set of 3 interchanges (T1, T11, T29) designated as Ta-b. (ii) Another set of 3 interchanges (T2, T3, T17) designated as Tc-d. (iii) A solitary interchange (T5) designated as Te-f. Further, for the identification of interchanged chromosomes in each of the interchange of the above tester set and in 7 other interchanges, their corresponding interchange homozygotes were subjected to simple karyotype analysis. In 4 of the 7 interchange homozygotes of the tester set, the interchanged chromosomes could be identified through altered chromosome morphology due to exchange of unequal chromosome segments. The results of intercrossing and karyotype analysis for chromosome identification were comparable and no discrepancy was observed. The altered chromosome morphology was also observed in the following 5 interchange homozygotes (not included in the tester set) : T9, T14, T15, T25, T44.

A preparation technique has been developed for plants with small chromosomes, which produces large numbers of good-quality mitotic preparations. The technique employs a hydrochloric acid treatment to hydrolyse the cytoplasm, facilitating the subsequent removal of cytoplasmic debris. The evaporative force of a methanol-based fixative is exploited to disperse the cytoplasm and to deposit the chromosomes in a single optical plane. This technique permits detailed observations of chromosome morphology and karyotyping. The mitotic preparations are also suitable for the complex analysis associated with in-situ hybridization, as in studies of genome interaction in plant hybrids.

The cytotaxonomical characteristics of parthenitae of Apatemon gracilis (Rudolphi, 1819) Szidat, 1928 were studied using karyometric analysis to extend our knowledge of chromosome morphology and karyosystematics among trematodes. The karyotype, reported here for the first time, consists of ten pairs (2n = 20) of chromosomes divided into two size groups: five pairs of comparatively large and five pairs of small chromosomes. Biarmed chromosomes prevail in the chromosome set. According to centromere index values, chromosome 1 is submetacentric to metacentric, 2 is subtelocentric, 3 and 5 are acrocentric, 4, 9 and 10 are metacentric, 6 is submetacentric and 7 and 8 are submeta-subtelocentric. The small uniarmed B-chromosome was found in the chromosome set of parthenitae of A. gracilis from one snail. Data are discussed with reference to the karyotypes previously described within the Strigeidae.

Summary A detailed morphological analysis of Coffea arabica pachytene chromosomes is presented for the first time. The pachytene chromomeric patterns revealed that there occurs some structural similarities in about 54% of the 22 bivalents. This fact is supported by two secondary associations observed, one of them involving one nucleolar bivalent. Based on these results, and other evidences from literature, it is suggested that C. arabica is a segmental alIopolyploid with genetically controlled chromosome pairing

The karyotype and external morphology of Leptothorax (Myrafant) ants, taken from nests at nine ‘Leptothorax tuberum’ localities in England and Wales, identifies them all as L. tuberointerruptus. Their karyotype differs in chromosome number and chromosome morphology from the karyotypes of morphologically similar European Leptothorax (Myrafant) species including L. tuberum, but matches the karyotype shared by L. tuberointerruptus and L. rougeti. Worker propodeal spine length, and worker propodeal spine shape coupled with worker gaster banding characteristics, distinguish the nest samples from L. rougeti. The presence of L. tuberointerruptus in Britain is therefore confirmed, and the data demonstrate this ant's occurrence throughout the British range attributed to L. tuberum. In the absence of equivalent data identifying L. tuberum as a British species, it may reasonably be assumed that L. tuberointerruptus has been misrecorded as L. tuberum in Britain and that all British mainland records of L. tuberum refer to L. tuberointerruptus. An examination of the syntypes of Stenamma albipennis shows that S. albipennis and L. tuberointerruptus are synonymous, and that L. albipennis is the senior name. It follows that L. albipennis is a scarce British ant of ‘Notable B’ conservation status. A taxonomic synopsis for L. albipennis is given.

Chromosome numbers are reported for the first time for seven taxa of Actinidia: A. arguta var. purpurea, 2n = 8x = c. 232; A. deliciosa var. chlorocarpa, 2n = 6x= 174; A. deliciosa var. coloris, 2n = 6x = 174; A. glaucophylla, 2n = 2x = 58; A. guilinensis, 2n = 2x = 58; A. indochinensis, 2n = 2x = 58 and A. setosa 2n = 2x = 58. Ploidy variation has also been observed in A. melanandra and confirmed in A. chinensis var. chinensis: 2n = 2x = 58 and 2n = 4x = 116. Chromosome numbers for another 11 Actinidia taxa were found to be in agreement with those previously reported. Chromosome numbers were the same for male and female plants of the same taxon. Detailed studies of chromosome morphology was not possible under the light micro scope because of the small size of Actinidia chromosomes.

SUMMARYA cytogenetic study, based on the comparative analysis of chromosome morphology, amount and distribution of C-positive heterochromatin and positions of NORs, was undertaken on three species of brown frogs (Rana temporaria, R. dalmatina and R. graeca) from different Balkan localities. In contrast to their uniform karyotypes with respect to chromosome number, important interspecies differences have been observed in centromeric indices, the amount of constitutive heterochromatin, the distribution of C-bands and the positions of NORs. Analysis of these karyotype characteristics suggests that mostly intrachromosomal rearrangements occurred during karyotype differentiation of the examined species.

From a comparative morphological viewpoint, we examined the development of gonads of 9 species of teleost fish, genus Oryzias, in which three types of bilateral asymmetry were discriminated. The first type occurs in O. celebensis, O. javanicus, O. marmoratus, O. mekongensis, O. melastigma, and O. minutillus, in which testes are completely asymmetrical. Their gonadal rudiments are constructed only on the right side and develop into testes of a unilobate form. The second type is exhibited in O. curvinotus and O. luzonensis, where gonadal rudiments appear unilateral only on the right side. But testicular tissue occurs on the left side of the dorsal mesentery during the development, and adult testes become biiobate. The testes of O. latipes belong to the third type. They initiated from bilateral gonadal rudiments to develop into bilobate testes, These results are almost correspond with the phylogenetical classification of Oryzias fishes based on the chromosome morphology, indicating that alleles of t...

The feasibility of using the same slide repeatedly for fluorescence in situ hybridization (FISH) experiments was systematically evaluated by applying standard procedures and various combinations of direct- and indirect-labeled probes to slides from patients with hematologic malignancies. Specific and distinct hybridization signals along with weak background signals and chromosome morphology of good to moderate quality could be obtained in up to three experiments performed consecutively on the same slide. Signals related to biotin- or digoxigenin-labeled probes applied in previous hybridizations were still visible with variable intensity, but interpretation problems that may result from this signal noise can be avoided by using adequate probes, detection systems and fluorochromes, and sequence of experiments.

Investigations concerning brown algal chromosomes have contributed to our understanding of the reproductive biology of brown algae. Techniques used in observing chromosomes in the light microscope are briefly summarized. Mitosis and meiosis are discussed, with an emphasis on aspects that are distinctive in the brown algae. Observations of chromosome morphology, although limited by the small size of brown algal chromosomes, have provided evidence for the existence of sex chromosomes. The few investigations quantifying brown algal genomes, and the potential for such techniques in further studies, are discussed. Most studies of brown algal chromosomes have been concerned with chromosome numbers, and reports for 183 species are presented along with discussions of the implications of these numbers on discerning basic chromosome numbers and patterns of chromosome numbers in taxonomic groups, and polyploidy. Many studies of brown algal chromosomes have been made in conjunction with life history studies,...

The genus Lippia (Verbenaceae) comprise around 160 species spread out mainly in South and Central Americas with few African species, some of them with potential medicinal use. Brazil is one the most important centers of diversity with approximately 75% of the species described so far. Innumerous species are endemic and poorly studied especially at a cytological level. Here, chromosomal length, karyomorphology and chromosome asymmetry of twelve Brazilian species of Lippia were evaluated [L. alba (Miller) N.E.Brown, L. diamantinensis Glaz., L. florida Cham., L. hermanioides Cham., L. lacunosa Mart. & Schauer, L. lupulina Cham., L. pohliana Schauer, L. pseudothea (St. Hil) Schauer, L. rosella Moldenke, L. rotundifolia Cham., L. rubella Moldenke and L. sidoides Cham.]. The analysis suggested that the genus has a variable chromosome number (from 2n = 20 to 2n = 56) originated by dysploidy and polyploidy. This is the first description of chromosome morphology for 11 of the 12 Lippia species studied.O gênero Lippia (Verbenaceae) possui cerca de 160 espécies distribuídas principalmente nas Américas Central e do Sul com poucas espécies Africanas, algumas delas com potencial uso medicinal. O Brasil é um dos mais importantes centros de diversidade com aproximadamente 75% das espécies descritas. Inúmeras espécies são endêmicas e pouco estudadas, principalmente a nível citológico. Aqui, o comprimento cromossômico, a cariomorfologia e a assimetria cromossômica de doze espécies brasileiras de Lippia foram avaliados [L. alba (Miller) N.E.Brown, L. diamantinensis Glaz., L. florida Cham., L. hermanioides Cham., L. lacunosa Mart. & Schauer, L. lupulina Cham., L. pohliana Schauer, L. pseudothea (St. Hil) Schauer, L. rosella Moldenke, L. rotundifolia Cham., L. rubella Moldenke e L. sidoides Cham.]. As análises sugeriram que o gênero tem um número cromossômico variável (de 2n = 20 a 2n = 56) originado por disploidia e poliploidia. Esta é a primeira descrição da morfologia cromossômica para 11 das 12 espécies de Lippia estudadas.

A population ofAllium rouyi,previously considered an extinct species, has recently been rediscovered. From this sample, the somatic chromosome number and detailed chromosome morphology is presented. Using the karyological data, relationships betweenA. rouyiand allied species are discussed.

A population of Allium rouyi, previously considered an extinct species, has recently been rediscovered. From this sample, the somatic chromosome number and detailed chromosome morphology is presented. Using the karyological data, relationships between A. rouyi and allied species are discussed.

The morphology of the chromosomes of the grasshopper, Zonocerus variegatus was studied from mitotic metaphase and meiotic stages in squashed preparations of fresh testicular material. The chromosomes (2n_??_=19) were found to be acrocentric as in most of the Pyrgomorphidae and not metacentric as reported in one study. No meiotic aberrations were detected.

Summary Cytotaxonomic study of Charophyte flora from lateritic belt of West Bengal, India, is being carried out. In the present communication, we present karyological observations of two ecorticated species of Chara, viz. C. wallichii A. Br. (dioecious) and C. braunii Gm. f. braunii R.D.W. (monoecious) collected from this region. Following refined pretreatment schedule, we have achieved marked improvement in chromosome preparation which helps to determine chromosome number accurately and reveal minute details of chromosome morphology. Chromosome numbers determined for both the taxa are n = 14, which confirms the earlier reports. Karyotypic details reveal distinct differences between these two species. This supports their distinct taxonomic position on the basis of differences in the disposition of sex organs, though there are some morphological similarities between these two species. Total form percent values (TF %) for C. wallichii and C. braunii f. braunii are 34.64 and 37.85 respectively, indicating sy...

closely related, if at all distinct. Limited evidence from previous cytological studies suggested a polyploid series within the complex where Arthropodium taxa have 2n = 22 chromosomes, intermediate species, 2n = 44, and Dichopogon taxa, 2n = 66. Examination of chromosomes in two thirds of the species in the Arthropodium-Dichopogon complex did not support that suggestion, as most of the species in both genera have a chromosome complement of 2n = 22. Evidence of polyploidy was found in D. strictus (2n = 22, 66), A. curvipes and D. preissii (2n = 44). The chromosomes are too small to provide useful information on chromosome morphology and Cband patterns. The lack of morphological features to delimit the two genera unequivocally, combined with the prevailing 2n = 22 karyotype across both, supports merging them under the name Arthropodium.

SUMMARYSpecimens of Alcyonidium verrilli from the lower Chesapeake Bay yielded 2n = 28. Spreads with good chromosome morphology were obtained from one colony, and a karyotype was prepared. There are three relatively large metacentric pairs; most of the smaller chromosomes are also metacentrics. Four pairs are submetacentrics, and satellites are present on the short arms of at least one of these pairs. We found no evidence of karyotypic variation in our limited sampling, although the colonies showed some morphological differences with respect to branch densities and growth patterns.

Summary Three subspecies under Nitella furcata (viz. furcata, mucronata, flagelliformis) were collected from different parts of the state of West Bengal, India. These three subspecies were studied cytotaxonomically in the present investigation. Earlier, data for cytotaxonomical studies were collected from chromosome preparation using unpretreated materials. A precise pretreatment schedule was followed in the present work, which helped in revealing the chromosome morphology distinctly. Subspecies furcata and mucronata showed a chromosome number of n = 18 while the chromosome number of flagelliformis was found to be n = 9. These findings confirmed the earlier reports of chromosome number counts of these three subspecies. An analysis of karyotypes constructed from pretreated metaphase plates and consideration of other cytological data, justified the creation of these three subspecies under Nitella furcata. Total form percent (TF%) were calculated for all the three taxa. TF% calculated for furcata, mucronata ...

The genus Parthenium contains plants which produce latex, although only P. argentatum produces the commercially important product, rubber, in sufficiently large quantities. Parthenium forms a natural polyploid series (Stebbins and Kodani 1944, Bergner 1944) and although many meiotic studies have been conducted, little mitotic karyological data has been published. This paper presents the first mitotic karyotype and idiogram of Parthenium argentatum (2n=36). In addition, a technique for production of well spread mitotic chromosome squashes is outlined.

The standard karyotypic properties of 60 of the 73 species of bats known to occur in southern Africa, are reviewed. The karyotypes of 23 microchiropteran species are described for the first time; our results on a further 14 species are compared with earlier reports for those taxa. The previously published chromosomal information pertaining to 23 species for which we had no information, are cited. Systematic implications of observed patterns of karyotypic variation are briefly discussed. In particular, we conclude that the taxon Cistugo (currently recognised as a subgenus oiMyotis) should be afforded full generic rank; hypothesise that the karyotypes of the two species - M. (C.) seabrai and M. (C.) lesueuri - in Cistugo are probably ancestral for all vespertilionids; and question the wisdom of redefining the taxonomic limits of the genera Eptesicus and Pipistrellus until molecular data are available to resolve the dilemma posed by conflicting morphological and cytogenetic data suites.

The somatic chromosome number and detailed chromosome morphology have been studied in populations of seven species of Ranunculus , namely Ranunculus alpestris L., R. glacialis L., R. thora L., R. seguieri Vill., R. aconitifolius L., R. platanifolius L. and R. acetosellifolius Boiss., from the Iberian Peninsula. Diploid levels have been found for these species in the samples studied. From the karyological data (karyograms, idiograms and asymmetry) relationships between these taxa are discussed.

Chromosome numbers are given for the following species of Taraxacum sect. Palustria from Poland: T. paucilobum Hudziok (2n = 24, 25), T. belorussicum Val. N. Tikhom. (2n = 24), T. subdolum Kirschner & Stěpanek (2n = 24), T. udum Jordan (2n = 24), T. trilobifolium Hudziok (2n = 24), T. bavaricum Soest (2n = 24), T. portentosum Kirschner & Stěpanek (2n = 32), T. vindobonense Soest (2n = 32), and T. brandenburgicum Hudziok (2n = 32). The chromosome numbers of T. belorussicum and T. portentosum are published for the first time, and for T. subdolum, T. bavaricum and T. brandenburgicum for the first time from Poland. The analyzed group of taxa is heterogenous in respect of stomatal size, and after pooling of data the tetraploids show bigger stomata than the triploids.

Hydrilla verticillata (L.f.) Royle root tip karyotypes were not different among 20 populations from Australia, China, India, Malaysia, Panama and the USA, and the combined karyotype derived from these populations was similar to that previously reported. Root tip tissue was sometimes endopolyploid, with diploid (2n = 2x = 16), triploid (2n = 3x = 24) and tetraploid (2n = 4x = 32) cells observed in the same populations, and diploid and triploid cells often observed in the same root tip. Diploid cells only were observed in root tips from a population of Panang Island. Hydrilla is probably diploid because diploid cells were observed in all populations (except Beijing, China, which was predominantly tetraploid). Therefore, there is no apparent reason why all populations should not be sexually compatible, and atleast partially fertile, based on chromosome make-up.

The higher magnifications and resolution possible with scanning electron microscopy can provide more detailed information on chromosome morphology than light microscopy. However, overlying cell debris can obscure surface details. A method is described whereby standard organic acid–alcohol fixatives and slightly modified techniques of routine plant chromosome squash preparations can be used to provide samples of mitotic and meiotic chromosomes of wheat suitable for examination by scanning electron microscopy.Key words: scanning electron microscopy, light microscopy, wheat, chromosomes.

SUMMARYThree populations of Plantago reniformis Beck from Yugoslavia (2n = 12) have been studied from a cytogenetical point of view. The karyotype carried out for the first time on the Treskavica population showed three pairs of metacentric (1, 2 and 5) and three pairs of submetacentric chromosomes (3, 4 and 6); pairs 3 and 6 carry satellites. This karyotype is symmetric for chromosome morphology (m and sm) as well as for their size which is between 1.88 and 2.92 μ. The interpopulation variability has been manifested in the arrangement of the different morphological types of chromosomes in the karyogram and in the number of satellite chromosomes. This variability observed in P. reniformis (a relictual endemic species) shows that our conception about the great karyological stability of old species like this one, is too rigid.

The karyotypes of Mycteria americana (Ciconiidae) and Platalea ajaja (Threskiornithidae) are described. Both species have a diploid number of 2n = 72. There are slight chromosome morphology differences, which could be related to distinct chromosome evolution pathways of these two families. Besides a better understanding of the chromosome relationships among Ciconiiformes, this first chromosome characterization of M. americana and P. ajaja is an important tool for the conservation of both species.No presente trabalho foram descritos os cariótipos de Mycteria americana (Ciconiidae) e Platalea ajaja (Threskiornithidae). Embora ambas as espécies tenham apresentado o número diplóide 2n = 72, foram observadas diferenças na morfologia cariotípica resultantes de processos evolutivos distintos que parecem ocorrer entre as duas famílias. Além de contribuir para um melhor entendimento da evolução cromossômica dentro da ordem Ciconiiformes, a caracterização cariotípica de M. americana e P. ajaja vem representar uma importante ferramenta para a realização de planos de manejo e conservação destas espécies.

WOS: 000272509600003, The somatic chromosome number of 22 taxa and chromosome morphology of 43 taxa of the Sideritis (Lamiaceae) genus of the Empedoclia section were determined for the first time using Image Analysis System, All the taxa in the Empedoclia section belonging to Sideritis in Turkey have the same chromosome number (2n=32) and basic chromosome number (x=16). The chromosome sizes of these taxa are close to each other. However, in these taxa the amounts of B chromosomes differ. Besides, the existence mixoploid cells, similar to the existence of B chromosomes, differ in some taxa as well. In 44 taxa there are B chromosomes; whereas in 11 taxa there are mixoploid cells. In this study, the results obtained were analysed karyologically within the taxa of this section., TUBITAK [TBAG-1853], We express our gratitude for financial support provided by TUBITAK (Project no. TBAG-1853). The authors would like to thank BABACAN UGUZ for providing Bs200Pro Image Analysis System.

The fecundity of an F1 male hybrid deer, from a cross between a male Odocoileus virginianus (white-tailed deer) and a female O. hemionus (mule deer), was assessed by cytogenetic and flow cytometric techniques. Analysis of chromosome morphology, nucleolus organizer expression, meiotic chromosome pairing, sperm production, and nuclear gene inheritance revealed no genetic anomalies that could potentially impair normal fertility. These observations are discussed in relation to recent reports of hybridization between natural populations of these two species.

Detailed karyomorphology of two morphologically distinct varieties of diploid taro (Colocasia esculenta) was studied. The karyotypes of the two morphotypes were found to be different in gross karyomorphology. The magnitude of difference between the karyotypes of these two morphotypes was striking and it appears to be more than what can be accounted for by mere structural changes of chromosomes of one type leading to the other. A taxonomic separation of the two morphotypes may be worth consideration.

The genomic evolution of triploid plants with regular bivalent formation is discussed. The conclusion is reached that although all the progeny of an originally triploid individual will be triploid numerically, only part of the progeny will be triploid genomically. The consequences of this for triploid identification by means of chromosome morphology and isozyme numbers is discussed.

A detailed karyotypic analysis and cytophotometric estimation of 4C DNA amount was carried out in six species of the subtribe Carinae of Umbelliferae. Intergeneric and interspecific chromosome number viz., 2n=14, 18, 20, 22 were varied in the subtribe level. Critical analysis of chromosome morphology revealed the structural alteration of chromosomes along with their changed DNA amount. Significant variation of DNA amount having numerical, gross or minor chromosomal alteration leads to the genetic drift in between the species of the subtribe suggesting the compromise between the structural and biochemical changes of the genome during macro- and micro-evolution.

Collected material of rare and newVicia spp. was investigated from a cytotaxonomic point of view. Nineteen species were examined in total. The study includes 14 novel chromosome counts and measurements of DNA amount, as well as a comparison of chromosome morphology between species. The results of the cytological study support to an extent a recent taxonomical revision of subgenusVicia.

A basic developmental framework of the Larix leptolepis Gord male gametophyte is presented in detail by squashing technique. The duration of the meiosis stage was more than 6 months, and included a long diffuse stage during winter. This long duration of the diffuse appearance of the diplotene stage makes L. leptolepis a unique suitable experimental material for studying the structure and function of the diffuse stage of meiosis. In particular, the processes of desynapsing and unpairing, which so far have received little attention, can be examined in detail. In L. leptolepis, the chromosomes undergo a dramatic structural reorganization during the diffuse diplotene stage. Based on the clearly visible differences in chromosome morphology, the diffuse diplotene stage was divided into four periods with suggested nomenclature as follows: schizonema, pre-diffuse diplotene, diffuse diplotene and post-diffuse diplotene. Both simultaneous and successive microsporogenesis were observed within L. leptolepis, and there was no strict relationship between the microsporogenesis types and the tetrad configurations, which are strongly influenced by spindle orientation, especially during meiosis II. The mature pollen grain at pollination consists of five cells aligned in an axial row. The prothallial cells cannot be regarded as senescent cells because they remain capable of division.

The similar-looking basic genomes ofHordeum bulbosum (2x and 4x) have five rather similar metacentric, one submetacentric, and one satellited choromosome. C-banding patterns are characterized by one or two centromeric, or juxtacentromeric, small to larger bands in most chromosomes, by bands at the nucleolar organizers, by small or very small telomeric bands, and by the nearly complete lack of intercalary bands. Banding pattern polymorphism is widespread. Banding patterns supported by chromosome morphology enable identification of homologues, and discrimination between non-homologues inH. bulbosum (2x). The C-banded karyotype ofH. bulbosum (4x) supports an autopolyploid origin, but it was possible to identify only homologues of submetacentrics and SAT-chromosomes.

Chromosome polymorphism inBelamchanda chinensis Dc. of the family Iridaceae, has been explored in detail. The root tip cells exhibited aneusomaty and differences in the morphology of chromosomes. About 70% cells were with 2n=30, 20% cells has 2n=28 and 10% cells were with 2n=32. Critical analysis of 3 typical cells with different chromosome numbers, selected out of several cells studied, exhibited varying proportions of long, medium and short chromosomes and different numbers of metacentric and submetacentric chromosomes. In these cells, while on one hand, all chromosomes could not be grouped in two's on the basis of chromosome morphology, certain chromosome paris were present more than once, on the other hand. The cytological basis of inconstancy in the chromosome complements within the cells of the same tissue and it's significance in the evolution of the vegetatively propagated plants have been discussed.

Karyotype of Canada wildrye (Elymus canadenisis L.) was described using giemsa C-banding techniques. Most of the chromosomes showed dome banding pattern polymorphism. Small to large terminal and centormere bands were observed in most of the chromosomes. A faint satellite was observed in one chromosome. Tow chromosomes had a large interstitial band near the centromeres in the long arms. The Giemsa C-banding pattern of E. Canadensis is compared to that of Pseudoroegneria spicata and Critesion boddanii to illustrate species relationship.

SUMMARYKaryotypical analysis of Crocus vernus (L.) Hill subsp. vernus (2n = 16 + 2B) and of Crocus etruscus Pari. (2n = 8) is reported. B-chromosomes in Crocus vernus (L.) Hill subsp. vemus are found for the first time. The karyological comparative analysis points out a true micromorphic differentiation between the two species considered.

Karyotypic analysis of 4 species of Urginea Steinh. from India has been made. All the taxa under study are diploids and showing 2n=20 and n=10 except U. indica where 2n=20+3B is also observed. Asymmetrical karyotype with all subtelocetric chromosomes was found as a characteristic of this genus. It has revealed from the present study that there are sharp specific differences at species level. However, close homology in U. indica, U. polyantha and U. razii while distant relationship of these taxa with U. congesta is confirmed. Speciation through structural alterations at chromosomal level and reproductive isolation through differences in time of flower blooming is discussed. Wide distribution and variation in U. indica and other species of Urginea in India is considered to be a result of evolution in secondary centre of variation.

The present paper is concerned with the morphology of the pachytene chromosomes of A. annua. Particular emphasis is placed on the identifying characteristics of each chromosome

SUMMARYP. sativum ect. abyssinicum was studied by karyotype and meiotic analyses. Two lines were investigated and resulted to be different from the standard P. sativum karyotype and from each other. Line 2 showed a reciprocal interchange involving chromosomes III and IV and both lines showed pericentric inversions in chromosome VI that involved different segments.

In the present study the karyological characteristics of three species of the genus Glycyrrhiza L. were described. Nine populations of G. echinata, one of G. glabra, and one of G. lepidota, which a...

In the present studies an attempt has been made to elucidate the karyomorphological details in some important mulberry cultivars of exotic origin