Did ‘Paleo-polyploidy’ Really occur in Proteaceae?

1998 ◽  
Vol 11 (4) ◽  
pp. 613 ◽  
Author(s):  
Helen M. Stace ◽  
Andrew W. Douglas ◽  
Jane F. Sampson
Keyword(s):  
Chromosome Number ◽  
Character State ◽  
Supporting Evidence ◽  
Ancestral Genome ◽  
High Chromosome Number ◽  
Cytological Data ◽  
The Family ◽  
Number Increase

Cytological data for 188 species in 65 genera of Proteaceae were collated from the literature. Excluding the occasional infrageneric polyploid, Proteaceae have seven confirmed character states for chromosome number (n = 14, 13, 12, 11, 10, 7, 5). Genera of subfamily Persoonioideae are x = 7, and, on a cytoevolutionary doctrine of ‘paleo-polyploidy’ in angiosperm families, these low chromosome number taxa were hypothesised to represent the ancestral genome of Proteaceae. Chief supporting evidence for this hypothesis is the ancient origin of Persoonioideae in Proteaceae phylogeny. However all current genomes in Proteaceae have features that suggest that they are derived, including those of Persoonioideae with their ‘genomic obesity’, and by reference to the chromosomes of Bellendenoideae (n = 5) and the outgroup Platanaceae (n = 21), quite probably their number is also a derived character state. Furthermore the high chromosome number genera of Proteaceae in subfamilies Proteoideae and Grevilleoideae (n = 14, 13, 12, 11, 10) have genomic lengths that are far smaller than would be expected from a doubling of the chromosomes of Persoonioideae, and, so far as any information is available, these genera are also genetic diploids. This paper questions ‘paleo-polyploidy’ as a general cytogenetic mechanism for plant macroevolution at the levels of genus, tribe and sub-family in Proteaceae. It is proposed that diploid cytoevolutionary processes of chromosome number increase and decrease from a primitive genome of FN = 24, with specific examples of x = 12 and x = 21, can explain the cytological phenomena in the family.

CYTOGENETICS OF SOME SPECIES AND NATURAL HYBRIDS IN PROSOPIS (LEGUMINOSAE)

1975 ◽  
Vol 17 (2) ◽  
pp. 253-262 ◽  
Author(s):  
J. H. Hunziker ◽  
L. Poggio ◽  
C. A. Naranjo ◽  
R. A. Palacios ◽  
A. B. Andrada
Keyword(s):  
Chromosome Number ◽  
Interspecific Hybrids ◽  
Vegetative Reproduction ◽  
General Lack ◽  
Cytological Data ◽  
Natural Hybrids ◽  
Regular Meiosis ◽  
Putative Hybrids

Cytological results on 12 species and 4 putative hybrids of Prosopis are presented. Of these, 5 species and 4 hybrids have been hitherto unknown cytologically. The following species proved to be diploid (2n = 28) and constitute new chromosome number determinations for the genus: P. algarobilla Griseb., P. hassleri Harms, P. nigra (Griseb.) Hieron., P. patagonica Speg., P. tamarugo Phil. The diploid nature of some races of P. juliflora (Sw.) DC. is established; apparently under this taxon there are also tetraploid populations. The following putative interspecific hybrids showed regular meiosis with formation of 14 bivalents: P. vinalillo Stuck. (P. ruscifolia × P. alba?), P. alba × P. nigra? and P. hassleri × P. ruscifolia?.So far 28 taxa of the genus have been studied cytologically; 27 of these are diploid. The scarcity of polyploidy in the genus (3.5%) might be a consequence of the almost general lack of means of vegetative reproduction and of the absence of chromosome repatterning in primary speciation. Results of other authors concerning cytological data are also discussed.

scholarly journals High Chromosome Number and Giant Postreductional Sex Chromosomes in the Beetle Walterianella venusta Schaufuss (Chrysomelidae, Alticinae)

1969 ◽  
Vol 47 (3) ◽  
pp. 154-163
Author(s):  
Niilo Virkki
Keyword(s):  
Chromosome Number ◽  
Sex Chromosomes ◽  
High Chromosome Number

A high chromosome number for a coleopteran, 22-J-X+y, was encountered in an alticine, Walterianella venusta Schaufuss. The autosomes are very short, metacentric; the sex chromosomes very long and also metacentric. The sex chromosomes are desynaptic and postreductional in spermatogenesis. It is assumed that two trends operate in the evolution of the alticine chromosomes, first, the autosomal chromatin being incorporated repeatedly in the sex chromosomes, and second, the occurrence of the multiplication of the short autosomes.

scholarly journals Contribution to the systematic knowledge of endemic Aubrieta pinardii Boiss. (Brassicaceae) from Turkey

2020 ◽  
Vol 27 (1) ◽  
pp. 27-35
Author(s):  
Emrah Şirin ◽  
Mehmet Cengiz Karaismailoğlu
Keyword(s):  
Electron Microscope ◽  
Chromosome Number ◽  
Scanning Electron Microscope ◽  
Geographical Distribution ◽  
Anatomical Structures ◽  
Seed Surface ◽  
Cytological Data ◽  
Surface Ornamentation ◽  
Systematic Knowledge ◽  
Scanning Electron

The aim of this study was to document the taxonomical, morphological, anatomical, palynological and cytological characters, and geographical distribution of endemic Aubrieta pinardii Boiss. (Brassicaceae) from Turkey. The description of the taxon was revised as a consequence of comprehensive assessments of many specimens. The surface pictures belonging to seed and pollen of the taxon were obtained by Scanning Electron Microscope. The seed surface ornamentation was rugose. The pollen was radially and isopolar and prolate in forms, with polar axes of 19.52 ± 0.29 μm and equatorial axes of 13.04 ± 0.22 μm, with oval outlines in the equatorial axes, and elliptical in the polar axes. They were three–colpate and colpus sizes varied between 12.98 μm and 13.29 μm in length, and between 1.33 and 2.09 μm in width. Also, the anatomical structures of the root, stem and leaf of species were studied. In cytological studies, the chromosome number of species was found as 2n = 16 (x =8). This was the first work including taxonomical, morphological (macro and micro), anatomical and cytological data of endemic Aubrieta pinardii. Bangladesh J.Plant Taxon. 27(1): 27-35, 2020 (June)

Observations on chromosomes and gametogenesis ofTransversotrema patialense(Trematoda)

Parasitology ◽  
1986 ◽  
Vol 92 (1) ◽  
pp. 245-252 ◽  
Author(s):  
R. Mad Havi ◽  
J. V. Ramanjaneyulu
Keyword(s):  
Chiasma Frequency ◽  
Chromosome Length ◽  
Cytological Data ◽  
Total Chromosome Length ◽  
Diploid Complement ◽  
The Family ◽  
Phylogenetic Status ◽  
Snail Tissue

SUMMARYThe karyotype ofTransversotrema patia1enconsists of 10 pairs of chromosomes (2n= 20) of which 5 pairs are metacentrics and 5 pairs are submetacentrics. The chromosomes are large and range in size from 5 to 12 μm. The total chromosome length of the diploid complement is 16783 μm. Stages of spermatogenesis including the two gonial divisions and two reduction divisions leading to production of spermatozoa occur in cercarial embryos inside snail tissue, while the maturation divisions of the ovum occur in eggs freshly liberated by the fluke. The chiasma frequency is high, being 3888/cell and 388/bivalent. Cytological data indicate an independent phylogenetic status for the family Transversotrematidae.

scholarly journals Karyotypic Analysis of four Species of Genus Blumea (Asteraceae) from Nepal

2018 ◽  
Vol 6 (2) ◽  
pp. 115-121
Author(s):  
Pushpa Karna Mallick
Keyword(s):  
Chromosome Number ◽  
Structural Variation ◽  
Chromosome Length ◽  
Evolutionary Significance ◽  
Satellite Chromosome ◽  
Middle Point ◽  
Karyotypic Analysis ◽  
The Family ◽  
Karyotype Formula ◽  
Blumea Lacera

In this study chromosome number determination and karyotype analysis of four species of genus Blumea from the family asteraceae was carried out. The specimen plants were collected from central parts of Nepal, namely  Blumea fistulosa (Roxb.) Kurz, Blumea lacera var.glandulosa (DC.) Hook, Blumea lacera (Buem f.) DC. and  Blumea laciniata DC were observed. The chromosome number in somatic cells were recorded to be 2n= 22 in Blumea fistulosa; 2n= 32 in  Blumea lacera var.glandulosa; 2n=18 in Blumea lacera and Blumea laciniata. The range of chromosome length found to be 0.6 to 1.6 µm in  Blumea fistulosa, 0.6 to 1.6µm in Blumea lacera var.glandulosa, 0.6 to 1.7 µm in Blumea lacera and 0.8 to 1.6 µm in Blumea laciniata. Karyotype formula for Blumea fistulosa is M12+ sm10, for Blumea lacera var. glandulosa is M14+sm14+ st4, for Blumea lacera is M14+ st2  and for Blumea laciniata is M12+ sm6 in  Blumea laciniata. In this investigation a pair of satellite chromosome found in  only one species Blumea  fistulosa at the end of shot arm of chromosome. Mainly three types of chromosomes observed in this study  having centromere at middle point, at sub-median region and at sub-terminal region. Numerical and structural variation in chromosome are evolutionary significance.  Similarity in size of chromosomes and karyomorphology indicates the homogeneity of the taxa within this tribe. Int. J. Appl. Sci. Biotechnol. Vol 6(2): 115-121

First Record on Sex Chromosomes in a Species of the Family Cynodontidae: Cynodon gibbus (Agassiz, 1829)

2020 ◽  
Vol 160 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Vanessa S. Pinheiro Figliuolo ◽  
Leonardo Goll ◽  
Patrik Ferreira Viana ◽  
Eliana Feldberg ◽  
Maria C. Gross
Keyword(s):  
Chromosome Number ◽  
Repetitive Dna ◽  
Sex Chromosomes ◽  
First Record ◽  
Diploid Chromosome Number ◽  
Fish Family ◽  
Female Heterogamety ◽  
The Family

The fish family Cynodontidae belongs to the superfamily Curimatoidea, together with the Hemiodontidae, Serrasalmidae, Parodontidae, Prochilodontidae, Chilodontidae, Curimatidae, and Anostomidae. The majority of the species of this superfamily that have been analyzed to date have a diploid chromosome number of 2n = 54. Differentiated sex chromosomes (with female heterogamety) have been observed only in the Prochilodontidae, Parodontidae, and Anostomidae. The present study provides the first description of differentiated sex chromosomes in the cynodontid species Cynodon gibbus, which has a ZZ/ZW system, and shows that repetitive DNA has played a fundamental role in the differentiation of these sex chromosomes.

Cytology of the fern flora of Tristan da Cunha

1968 ◽  
Vol 170 (1021) ◽  
pp. 361-379 ◽  
Keyword(s):  
Chromosome Number ◽  
Southern Hemisphere ◽  
Endemic Species ◽  
Special Interest ◽  
New Record ◽  
Atlantic Basin ◽  
High Chromosome Number ◽  
Tristan Da Cunha

Twenty species out of a total of twenty-six leptosporangiate ferns known to occur on Tristan da Cunha have been examined cytologically. Four species have been independently examined from Gough with concordant results. Hymenophyllum tunbrigense , included among the Tristan species, is a new record for the island. Other points of special interest about individual taxa include demonstration of an extremely high chromosome number ( n = 174) in the supposedly endemic species Eriosorus cheilanthoides , demonstration of the existence of two different cytotypes (one only present on Tristan) within Blechnum penna-marina in the southern hemisphere and of complex polyploid relationships affecting several other taxa which are discussed individually. In addition the cytological composition of the fern flora as a whole is discussed in relation to other temperate and tropical floras in or near the Atlantic basin.

Cytogenetic studies on Sauria (Reptilia). I. Mitotic chromosomes of the Agamidae

1988 ◽  
Vol 9 (3) ◽  
pp. 301-310 ◽  
Author(s):  
E. Solleder ◽  
M. Schmid
Keyword(s):  
Chromosome Number ◽  
Chromosome Morphology ◽  
Mitotic Chromosomes ◽  
Metaphase Chromosomes ◽  
Banding Patterns ◽  
The Family ◽  
Telocentric Chromosomes ◽  
Cytogenetic Studies ◽  
Pericentric Inversions ◽  
Dna Organization

The karotypes of nine species of the family Agamidae were analyzed with various banding techniques and conventional cytogenetic stainings. Whereas the examined species of the genera Calotes and Leiolepis exhibit conservative karyotypes, the chromosome number and chromosome morphology varies considerably within the genus Agama. This is attributed to centric fusions between telocentric chromosomes and pericentric inversions within the chromosomes. None of the species demonstrated multiple quinacrine banding patterns in the euchromatic segments of the metaphase chromosomes. This is probably due to the special DNA organization in these organisms.

scholarly journals Joint Family Households and Rural Notables in 19th-Century Egypt

1995 ◽  
Vol 27 (4) ◽  
pp. 485-502 ◽  
Author(s):  
Kenneth M. Cuno
Keyword(s):  
19Th Century ◽  
Social Relations ◽  
Law Reform ◽  
Reform Process ◽  
Supporting Evidence ◽  
Joint Family ◽  
Large Joint ◽  
The Family ◽  
The 19Th Century ◽  
Egyptian History

During the past thirty years, the study of the family in European history has developed with a strong comparative emphasis. In contrast, the study of the family in Middle East history has hardly begun, even though the family is assumed to have had a major role in “the structuring of economic, political, and social relations,” as Judith Tucker has noted. This article takes up the theme of the family in the economic, political, and social context of 19th-century rural Egypt. Its purpose is, first of all, to explicate the prevailing joint household formation system in relation to the system of landholding, drawing upon fatwas and supporting evidence. Second, it argues that rural notable families in particular had a tendency to form large joint households and that this was related to the reproduction and enhancement of their economic and political status. Specifically, the maintenance of a joint household appears to have been a way of avoiding the fragmentation of land through inheritance. After the middle of the 19th century, when it appeared that the coherence and durability of the joint family household were threatened, the notables sought to strengthen it through legislation. Their involvement in the law reform process contradicts the progressive, linear model of social and legal change that is often applied in 19th-century Egyptian history.

scholarly journals Genome size stability despite high chromosome number variation in Carex gr. laevigata

2015 ◽  
Vol 102 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Marcial Escudero ◽  
Enrique Maguilla ◽  
João Loureiro ◽  
Mariana Castro ◽  
Sílvia Castro ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Genome Size ◽  
High Chromosome Number ◽  
Size Stability ◽  
Number Variation ◽  
Chromosome Number Variation
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