Phylogenetics and chromosomal evolution in the Poaceae (grasses)

The wide range in basic chromosome number (x = 2–18) and prevalence of polyploidy and hybridisation have resulted in contrasting views on chromosomal evolution in Poaceae. This study uses information on grass chromosome number and a consensus phylogeny to determine patterns of chromosomal evolution in the family. A chromosomal parsimony hypothesis is proposed that underscores (1) the evolution of the Joinvilleaceae/Ecdeiocoleaceae/Poaceae lineage from Restionaceae ancestors with x = 9, (2) aneuploid origin of x�=�11 in Ecdeiocoleaceae and Poaceae (Streptochaeta, Anomochlooideae), (3) reduction to x = 9, followed by chromosome doubling within Anomochlooideae to generate the x = 18 in Anomochloa, and (4) aneuploid increase from the ancestral x = 11 to x = 12 in Pharoideae and Puelioideae, and further diversification in remaining taxa (Fig. 3b). Higher basic chromosome numbers are maintained in basal taxa of all grass subfamilies, whereas smaller numbers are found in terminal species. This finding refutes the 'secondary polyploidy hypothesis', but partially supports the 'reduction hypothesis' previously proposed for chromosomal evolution in the Poaceae.

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Malpighiaceae: correlations between habit, fruit type and basic chromosome number

Acta Botanica Brasilica ◽

10.1590/s0102-33062003000200001 ◽

2003 ◽

Vol 17 (2) ◽

pp. 171-178 ◽

Cited By ~ 8

Author(s):

Ricardo A. Lombello ◽

Eliana R. Forni-Martins

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Basic Number ◽

Basic Chromosome Number ◽

Basic Chromosome ◽

Monophyletic Origin ◽

The Family ◽

Number Variation ◽

Family Based ◽

The Relationship

The family Malpighiaceae presents species with different habits, fruit types and cytological characters. Climbers are considered the most derived habit, followed, respectively, by the shrubby and arboreal ones. The present study examines the relationship between basic chromosome numbers and the derivation of climbing habit and fruit types in Malpighiaceae. A comparison of all the chromosome number reports for Malpighiaceae showed a predominance of chromosome numbers based on x=5 or 10 in the genera of sub-family Malpighioideae, mainly represented by climbers with winged fruits, whereas non-climbing species with non-winged fruits, which predominate in sub-family Byrsonimoideae, had counts based on x=6, which is considered the less derived basic number for the family. Based on such data, confirmed by statistic assays, and on the monophyletic origin of this family, we admit the hypothesis that morphological derivation of habit and fruit is correlated with chromosome basic number variation in the family Malpighiaceae.

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EVIDENCE OF TWO CENTRIC FUSIONS IN CHROMOSOME COMPLEMENTS OF NODITERMES LAMANIANUS

Canadian Journal of Genetics and Cytology ◽

10.1139/g78-055 ◽

1978 ◽

Vol 20 (4) ◽

pp. 483-484

Author(s):

P. P. Vincke ◽

J. P. Tilquin

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Basic Chromosome Number ◽

Basic Chromosome ◽

The Family

From a survey of chromosome numbers in Termitidae, it appears that Noditermes laminianus Sjöstedt (Isoptera, Termitidae) and Procubitermes sp. 1 have n = 19 instead of n = 21 as is usually found in the African members of the family. A detailed investigation on N. lamanianus demonstrates that this feature is constant in the area of distribution of this species. This change in the basic chromosome number is explained as the result of two centric fusions.

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Relations and evolution in Cheilanthes (Sinopteridaceae, Pteridophita) in Macaronesia and Mediterranean area, deduced from genome analysis of their hybrids

Acta Botanica Malacitana ◽

10.24310/actabotanicaabmabm.v8i.9648 ◽

1983 ◽

Vol 8 ◽

pp. 101-126 ◽

Cited By ~ 2

Author(s):

G. Vida ◽

A. Major ◽

T. Reichstein

Keyword(s):

Chromosome Number ◽

Genome Analysis ◽

Chromosome Doubling ◽

Diploid Species ◽

Mediterranean Area ◽

Basic Chromosome Number ◽

The Other ◽

Experimental Conditions ◽

Natural Group ◽

Basic Chromosome

Nine species of "Cheilantoid ferns" are known to grow in Macaronesia and the Mediterranean basin. Two of them (lacking a pseudo-indusium and having the basic chromosome number X = 29), both aggregate species which we prefer to retain in Notholaena, are not included in this study. The other seven species (with distinct pseudo-indusium and the basic chromosome number X = 30), which we accept as members of the genus Cheilanthes Sw. sensu stricto, were subjected to detailed genome analysis of their natural and experimentally produced hybrids and shown to represent an aggregate of four very distinct ancestral diploids and three allotetraploids. The latter must have once been formed by chromosome doubling in the three diploid hybrids of C. maderensis Lowe with the other three diploid species. Theoretically three more allotetraploids would be possible but their formation has obviously been prevented by the geographical separation of the three respective diploids. The most widely distributed of the tetraploids, i.e. C. pteridioides (Reich.) C.Chr. has also been resynthesized from its ancestors (still sympatric) under experimental conditions. The intermediate morphology of the allotetraploids (as compared with their diploid ancestors) is obviously the reason why their status and existence has so long escaped recognition in Europe. These seven species form a natural group and, in our opinion, should not be divided into sections.

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Chromosome studies on African plants. 9. Chromosome numbers in Ehrharta (Poaceae: Ehrharteae)

Bothalia ◽

10.4102/abc.v19i1.948 ◽

1989 ◽

Vol 19 (1) ◽

pp. 125-132 ◽

Cited By ~ 2

Author(s):

J. J. Spies ◽

E. J. L. Saayman ◽

S. P. Voges ◽

G. Davidse

Keyword(s):

Chromosome Number ◽

Ploidy Level ◽

Chromosome Numbers ◽

Basic Chromosome Number ◽

B Chromosomes ◽

Basic Chromosome ◽

Cytogenetic Studies ◽

African Plants ◽

First Time

Cytogenetic studies of 53 specimens of 14 species of the genus Ehrharta Thunb. confirmed a basic chromosome number of 12 for the genus. Chromosome numbers for 13 species are described for the first time. The highest ploidy level yet observed in the genus (2n = lOx = 120) is reported for E. villosa var. villosa. B chromosomes were observed in several specimens of four different species.

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The taxonomy of the Viola nuttallii complex

Canadian Journal of Botany ◽

10.1139/b87-347 ◽

1987 ◽

Vol 65 (12) ◽

pp. 2562-2580 ◽

Cited By ~ 6

Author(s):

D. M. Fabijan ◽

J. G. Packer ◽

K. E. Denford

Keyword(s):

Chromosome Number ◽

Phylogenetic Relationships ◽

Basic Chromosome Number ◽

Chemical Diversity ◽

Statistical Analyses ◽

Polyploid Complex ◽

Basic Chromosome ◽

Wide Range ◽

Flavonoid Chemistry

Morphological, cytological, and phytochemical data were incorporated into numerical and statistical analyses to produce a revision of Viola subsection Nuttallianae. A basic chromosome number of x = 6 was confirmed for this polyploid complex, which includes five species: V. vallicola, 2n = 12; V. tomentosa, 2n = 12; V. nuttallii, 2n = 24; V. praemorsa, 2n = 36 and 48; and V. bakeri, 2n = 48. Departures from recent authors include the recognition of two varieties in V. vallicola, vallicola and major (Hook.) Fabijan, based on flavonoid chemistry and distribution. Viola praemorsa is envisaged as embracing a wide range of morphological and chemical diversity, the extremes of which are recognized as the subspecies praemorsa, flavovirens (Pollard) Fabijan, and linguaefolia. In the absence of significant morphological or distributional differences between the V. linguaefolia and V. praemorsa subspecies major (sensu Baker and Clausen) and oregona, these three previously recognized taxa are included in subspecies linguaefolia. Based on cytological, morphological, and flavonoid data presented here, possible phylogenetic relationships are discussed.

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Chromosome numbers in some species of Trifolium

Australian Journal of Agricultural Research ◽

10.1071/ar9690883 ◽

1969 ◽

Vol 20 (5) ◽

pp. 883 ◽

Cited By ~ 11

Author(s):

AJ Pritchard

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Basic Chromosome Number ◽

Basic Chromosome ◽

First Time

The chromosome numbers of 31 species of Trifolium are reported, 18 for the first time. A reduction in basic chromosome number has occurred only in the three most highly specialized subgenera, and polyploids occur mainly in one of the more primitive subgenera.

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A New Basic Chromosome Number in the Family Fagaceae

Nature ◽

10.1038/2051340b0 ◽

1965 ◽

Vol 205 (4978) ◽

pp. 1340-1341 ◽

Cited By ~ 12

Author(s):

JEAN M. ARMSTRONG ◽

ANN P. WYLIE

Keyword(s):

Chromosome Number ◽

Basic Chromosome Number ◽

Basic Chromosome ◽

The Family

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Fertility of Triploid Highbush Blueberry

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.116.2.336 ◽

1991 ◽

Vol 116 (2) ◽

pp. 336-341 ◽

Cited By ~ 15

Author(s):

N. Vorsa ◽

James R. Ballington

Keyword(s):

Gene Transfer ◽

Chromosome Number ◽

Chromosome Numbers ◽

2N Gametes ◽

Basic Chromosome Number ◽

Highbush Blueberry ◽

Pollen Stainability ◽

Frequency Distributions ◽

Basic Chromosome ◽

2N Gamete

Eight highbush blueberry (V. corymbosum L.) triploids (2n = 3x = 36) were crossed with diploids (2n = 2x = 24), tetraploids (2n = 4x = 48), and hexaploids (2n = 6x = 72). No plants were recovered from 4021 3x × 2x crosses. One triploid was relatively fertile in 3x × 4x and 3x × 6x crosses, which is most likely attributable to 2n gamete production in the triploid. The lack of fertility of triploids, which do not produce 2n gametes, in crosses with diploids and tetraploids suggests that the production of gametes with numerically balanced (n = 12 or 24) chromosome numbers is extremely low. In addition, the inability to recover progeny from 3x × 2x crosses also suggests that aneuploid gametophytes and/or zygotes, including trisomics, are inviable in blueberry. Pollen stainability was also highly reduced in triploids. Frequency distributions of anaphase I pole chromosomal constitutions of three triploids were significantly different from one another. Two of the three distributions were shifted toward the basic chromosome number of 12, with one triploid having 25% poles with 12 chromosomes. However, the sterility of 3x × 2x and 2x × 3x crosses indicates that lagging chromosomes during meiotic anaphases are probably not excluded from gametes, resulting in unbalanced gametes in blueberry. Triploids can be used as a bridge to facilitate gene transfer from the diploid and tetraploid levels to the hexaploid level in blueberry.

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Chromosome numbers of selected species of Elatine L. (Elatinaceae)

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2015.036 ◽

2015 ◽

Vol 84 (4) ◽

pp. 413-417 ◽

Cited By ~ 2

Author(s):

Anna Kalinka ◽

Gábor Sramkó ◽

Orsolya Horváth ◽

Attila Molnár V. ◽

Agnieszka Popiela

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Basic Chromosome Number ◽

Basic Chromosome ◽

First Time

The paper reports chromosome numbers for 13 taxa of Elatine L., including all 11 species occurring in Europe, namely E. alsinastrum, E. ambigua, E. brachysperma, E. brochonii, E. californica, E. campylosperma, E. gussonei, E. hexandra, E. hungarica, E. hydropiper, E. macropoda, E. orthosperma, E. triandra originating from 17, field-collected populations. For seven of them (E. ambigua, E. californica, E. campylosperma, E. brachysperma, E. brochonii, E. hungarica, E. orthosperma) the chromosome numbers are reported for the first time. With these records, chromosome numbers for the whole section Elatinella Seub. became available. Although 2n = 36 was reported to be the most common and the lowest chromosome number in the genus, our data show that out of thirteen species analyzed, six had 36 chromosomes but five species had 54 chromosomes, and the lowest number of chromosomes was 18. These data further corroborates that the basic chromosome number in Elatine is x = 9.

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Genome size, chromosome number determination, and analysis of the repetitive elements in Cissus quadrangularis

PeerJ ◽

10.7717/peerj.8201 ◽

2019 ◽

Vol 7 ◽

pp. e8201

Author(s):

Duncan Kiragu Gichuki ◽

Lu Ma ◽

Zhenfei Zhu ◽

Chang Du ◽

Qingyun Li ◽

...

Keyword(s):

Chromosome Number ◽

Genome Size ◽

Chromosome Numbers ◽

Arid Regions ◽

Repetitive Elements ◽

Repeat Elements ◽

Cissus Quadrangularis ◽

Wide Range ◽

The Family ◽

Animal Medicine

Cissus quadrangularis (Vitaceae) is a perennial climber endemic to Africa and is characterized by succulent angular stems. The plant grows in arid and semi-arid regions of Africa especially in the African savanna. The stem of C. quadrangularis has a wide range of applications in both human and animal medicine, but there is limited cytogenetic information available for this species. In this study, the chromosome number, genome size, and genome composition for C. quadrangularis were determined. Flow cytometry results indicated that the genome size of C. quadrangularis is approximately 2C = 1.410 pg. Fluorescence microscopy combined with DAPI stain showed the chromosome numbers to be 2n = 48. It is likely that C. quadrangularis has a tetraploid genome after considering the basic chromosome numbers in Cissus genus (n = 10, 11, or 12). A combination of low-throughput genome sequencing and bioinformatics analysis allowed identification and quantification of repetitive elements that make up about 52% of the C. quadrangularis genome, which was dominated by LTR-retrotransposons. Two LTR superfamilies were identified as Copia and Gypsy, with 24% and 15% of the annotated clusters, respectively. The comparison of repeat elements for C. quadrangularis, Vitis vinifera, and four other selected members in the Cissus genus revealed a high diversity in the repetitive element components, which could suggest recent amplification events in the Cissus genus. Our data provides a platform for further studies on the phylogeny and karyotype evolution in this genus and in the family Vitaceae.

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