Cytogenetic studies in some representatives of the subfamily Pooideae (Poaceae) in South Africa. 1. The tribe Aveneae, subtribe Aveninae

Bothalia ◽  
1996 ◽  
Vol 26 (1) ◽  
pp. 53-61 ◽  
Author(s):  
J. J. Spies ◽  
S. K. Spies ◽  
S. M. C. Van Wyk ◽  
A. F. Malan ◽  
E. J. L. Liebenberg
Keyword(s):  
South Africa ◽  
Chromosome Number ◽  
Chromosome Numbers ◽  
Basic Chromosome Number ◽  
Ploidy Levels ◽  
Basic Chromosome ◽  
The World ◽  
Cytogenetic Studies

This is a report on chromosome numbers for 14 species of the subtribe Aveninae. which is largely naturalized in South Africa. This is the first chromosome number report for Helictotrichon longifolium (Nees) Schweick. (n = 14). H. longum (Stapf)Schweick. (n = 14). H. namaquensis Schweick. (n = 14) and Lophochloa cristata (L.) Hyl. (n = 7, 21/2. 14). The subtribe has a basic chromosome number of seven, and fewer ploidy levels occur in the naturalized species in South Africa than in the same species in other parts of the world. All tetraploid specimens were alloploids.

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

Bothalia ◽  
1989 ◽  
Vol 19 (1) ◽  
pp. 125-132 ◽  
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.

scholarly journals Chromosome Numbers of Rubus Species at the National Clonal Germplasm Repository

HortScience ◽  
1995 ◽  
Vol 30 (7) ◽  
pp. 1447-1452 ◽  
Author(s):  
Maxine M. Thompson
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Agricultural Research ◽  
Basic Chromosome Number ◽  
Ploidy Levels ◽  
Basic Chromosome ◽  
Rubus Species ◽  
Agricultural Research Service ◽  
The U.S ◽  
Research Service

The U.S. Dept. of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository (NCGR), Corvallis, Ore., maintains Rubus germplasm representing worldwide diversity of the genus. Chromosome numbers were counted for 201 plants representing 124 taxa (species and varieties). There are new reports for 42 taxa, confirmation for 72 previously reported, and 10 counts for plants unidentified to species. The basic chromosome number was seven, and ploidy levels ranged from 2x to 12x.

Cytogenetic studies in some representatives of the subfamily Pooideae (Poaceae) in South Africa. 3. The tribe Poeae

Bothalia ◽  
1997 ◽  
Vol 27 (1) ◽  
pp. 75-82 ◽  
Author(s):  
J. J. Spies ◽  
S. M. C. Van Wyk ◽  
I. C. Nieman ◽  
E. J. L. Liebenberg
Keyword(s):  
South Africa ◽  
Chromosome Numbers ◽  
Ploidy Levels ◽  
Cytogenetic Studies

This is a report on chromosome numbers for the tribe Poeae, which is represented in South Africa mainly by naturalized exotics. Chromosome numbers of 67 specimens, representing 26 species and 11 genera, are presented. These numbers include the first reports on Poa binata Nees (n = 3x = 21 and n = 4x = 28), Puccinellia acroxantha C.A.Sm. CE.Hubb. (n = 3x = 21) and P. angusta (Nees) C.A.Sm. C.E.Hubb. (n = x = 7). New ploidy levels are reported for Catapodium rigidum (L.) CE.Hubb.(n = 2x = 14), Festuca caprina Nees (n = 2x = 14) and F. scabra Vahl (n = x = 7).

Chromosome numbers in some species of Trifolium

1969 ◽  
Vol 20 (5) ◽  
pp. 883 ◽  
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.

scholarly journals Fertility of Triploid Highbush Blueberry

1991 ◽  
Vol 116 (2) ◽  
pp. 336-341 ◽  
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.

scholarly journals Cytogenetic studies in some species of Passiflora L. (Passifloraceae): a review emphasizing Brazilian species

2008 ◽  
Vol 51 (2) ◽  
pp. 247-258 ◽  
Author(s):  
Margarete Magalhães Souza ◽  
Telma N. Santana Pereira ◽  
Maria Lúcia Carneiro Vieira
Keyword(s):  
Chromosome Number ◽  
Genome Size ◽  
Pollen Viability ◽  
Basic Chromosome Number ◽  
Meiotic Behavior ◽  
Basic Chromosome ◽  
Brazilian Species ◽  
Cytogenetic Studies ◽  
Basic Numbers

The Passifloraceae is represented by species of tropical and subtropical origin. The Passiflora is the richest genus with approximately 450 species, 200 of them being native to Brazil. Recent karyological studies have reported the basic chromosome number for the Passiflora genus as x = 6, whereas x = 9, x = 10 and x = 12 were established as secondary basic numbers. High rates of fertility occur in most Passiflora species, since both meiotic index and pollen viability are above 90%. Unusual meiotic behavior has been described in some taxa. Unviable pollen were observed in some diploids species. The genome size varies from 1.83 to 5.36 pg, and significant interspecific variance has been observed. Studies using the FISH methodology have shown that there are two to three rDNA 45S sites and one 5S site in the species analyzed. In this review, information about the above-mentioned studies is presented and discussed in detail.

Phylogenetics and chromosomal evolution in the Poaceae (grasses)

2004 ◽  
Vol 52 (1) ◽  
pp. 13 ◽  
Author(s):  
Khidir W. Hilu
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosome Doubling ◽  
Chromosomal Evolution ◽  
Basic Chromosome Number ◽  
Basic Chromosome ◽  
Wide Range ◽  
The Family

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.

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

2015 ◽  
Vol 84 (4) ◽  
pp. 413-417 ◽  
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 <em>Elatine</em> L., including all 11 species occurring in Europe, namely <em>E. alsinastrum</em>, <em>E. ambigua</em>, <em>E. brachysperma</em>, <em>E. brochonii</em>, <em>E. californica</em>, <em>E. campylosperma</em>, <em>E. gussonei</em>, <em>E. hexandra</em>, <em>E. hungarica</em>, <em>E. hydropiper</em>, <em>E. macropoda</em>, <em>E. orthosperma</em>, <em>E. triandra</em> originating from 17, field-collected populations. For seven of them (<em>E. ambigua</em>, <em>E. californica</em>, <em>E. campylosperma</em>, <em>E. brachysperma</em>, <em>E. brochonii</em>, <em>E. hungarica</em>, <em>E. orthosperma</em>) the chromosome numbers are reported for the first time. With these records, chromosome numbers for the whole section <em>Elatinella</em> Seub. became available. Although 2<em>n</em> = 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 <em>Elatine</em> is <em>x</em> = 9.

scholarly journals Cytological Investigation of Brazilian Nightshade (Solanum seaforthianam Andr.)

2014 ◽  
Vol 15 ◽  
pp. 44-48
Author(s):  
D. Jagatheeswari
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosome Complement ◽  
Basic Chromosome Number ◽  
Cytological Investigation ◽  
Ancestral Species ◽  
Basic Chromosome ◽  
Centromere Position ◽  
Solanaceae Family

Solanum genus namely Solanum seaforthianum Andr. belongs to the Solanaceae family, and comprises only dioeciously species. These plants are distributed between 29º and 40º south. All species of this genus are diploid with chromosome numbers of 2n = 24, 28 and 30. According to literature, the basic chromosome number in this genus is x = 12, 14 and 15. Solanum genus with a chromosome complement of 2n = 30 has a symmetric karyotype with a median and sub median centromere position. Because ancestral species have a symmetric karyotype, it seems that x = 12 is the initial basic chromosome number in this genus and the x = 14 and x = 15 derived from x = 12. So it seems that diploid phenomena played an important role in evolution and speciation

scholarly journals Morphological and Cytological Characterization of Five Porterweed (Stachytarpheta) Selections

HortScience ◽  
2021 ◽  
pp. 1-6
Author(s):  
Renjuan Qian ◽  
S. Brooks Parrish ◽  
Sandra B. Wilson ◽  
Gary W. Knox ◽  
Zhanao Deng
Keyword(s):  
Chromosome Number ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Basic Chromosome Number ◽  
Pollen Stainability ◽  
Flower Number ◽  
Ploidy Levels ◽  
Basic Chromosome

Porterweed (Stachytarpheta spp.), a member of the verbena family, is frequently used in pollinator gardens to attract butterflies. This study was conducted to assess the morphological features, pollen stainability and morphology, nuclear DNA content, and chromosome number of five porterweed selections. Coral porterweed (S. mutabilis), ‘Naples Lilac’ porterweed (S. cayennensis × S. mutabilis ‘Violacea’), and nettleleaf porterweed (S. cayennensis) had the largest plant heights. Flower number was significantly higher in nettleleaf porterweed, jamaican porterweed (S. jamaicensis), and U*J3-2 porterweed (S. cayennensis × S. jamaicensis), with an average of 65–72 flowers per inflorescence. Internode length and flower width of jamaican porterweed had much lower values than the other selections. Coral porterweed recorded the lowest pollen stainability with only 10.6% stainability, but it had the largest relative pollen production. ‘Naples Lilac’ porterweed had the highest DNA content with an average of 3.79 pg/2C, like jamaican porterweed with 3.73 pg/2C. Ploidy levels varied between selections, and the basic chromosome number was x = 28. Coral, jamaican, and ‘Naples Lilac’ porterweed had 2n = 6x = 168 chromosomes, first reported in this genus. These results provide a guide and a new tool to distinguish native and non-native porterweed and may aid future breeding toward the production of noninvasive cultivars.

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