AlyBase: database of names, chromosome numbers, and ploidy levels of Alysseae (Brassicaceae), with a new generic concept of the tribe

Cirsium Mill. contains more than 250 species in the world mainly distributed in the Northern hemisphere. Different chromosome numbers with different ploidy levels were reported in this genus. In this study, karyotype details and chromosome numbers were established for two Cirsium taxa in Iran. C. ciliatum subsp. szovitsii and C. echinus had the mitotic chromosome numbers of 2n = 2x = 34. Karyotype analyses showed that chromosomes were generally metacentric and sub-metacentric. In C. echinus, Lowshan population had the longest chromosome (19.10 µm) and Heyran Canyon population (4.73 µm) the shortest one while in C. ciliatum, the longest chromosome was observed in Urmia to Salmas population (14.67 µm) and the shortest one (4.71 µm) in Doshanlu population. Total haploid chromosome length ranged from 275.29 to 376.42 µm in populations studied. Both taxa were grouped in 2B class. B-chromosomes were recorded for two taxa studied too. Chromosome type, mitotic chromosome numbers and occurrence of B-chromosomes were in agreement with previous results (Albers, Pröbsting, 1998; Lövkvist, Hultgård, 1999; Yüksel et al., 2013; Yildiz et al., 2016).

Download Full-text

Karyotype Analysis of Alnus Mill. (Betulaceae) Species Originating From Northeastern Asia

Silvae Genetica ◽

10.1515/sg-2010-0026 ◽

2010 ◽

Vol 59 (1-6) ◽

pp. 219-223 ◽

Cited By ~ 1

Author(s):

Liu Jun ◽

Ren Bao-Qing ◽

Luo Peigao ◽

Ren Zhenglong

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Karyotype Analysis ◽

Full Potential ◽

Northeastern Asia ◽

Ploidy Levels ◽

Genetic Makeup ◽

Fossil Records

Abstract Alnus Mill. (alder) is an ecologically valuable tree genus. It is essential to study its genetic makeup in order to use alder trees to their full potential. Five specimens from four Alnus species (A. mandshurica, A. pendula, A. sibirica, and A. sieboldiana), found in northeastern Asia, were subjected to karyotype analysis. The analysis showed that these tree samples could be divided into three categories based on chromosome numbers or ploidy levels: viz., 2n = (4x) = 28, 2n = (8x) = 56 and 2n = (16x) = 112. The differences in chromosome number and karyotype parameters among Alnus species and even within the same species possibly resulted from natural polyploidization. Comparing the chromosome numbers of Alnus species in China with those in Japan showed that there appear to be only two categories in China, whereas there are up to five categories in Japan. The earliest fossil records of Alnus pollen were also discovered in Japan. We conclude that the center origin of Alnus spp. is Japan rather than China.

Download Full-text

Cytogenetics and Genome Size Evolution in Illicium L.

HortScience ◽

10.21273/hortsci12922-18 ◽

2018 ◽

Vol 53 (5) ◽

pp. 620-623

Author(s):

Thomas G. Ranney ◽

Connor F. Ryan ◽

Lauren E. Deans ◽

Nathan P. Lynch

Keyword(s):

North America ◽

Plant Breeding ◽

Genome Size ◽

Chromosome Numbers ◽

Phylogenetic Analyses ◽

Basal Angiosperm ◽

Ploidy Levels ◽

Genome Size Evolution ◽

Size Evolution ◽

Improvement Programs

Illicium is an ancient genus and member of the earliest diverging angiosperms known as the Amborellales, Nymphaeales, and Austrobaileyales (ANA) grade. These adaptable, broadleaf evergreen shrubs, including ≈40 species distributed throughout Asia and North America, are valued for diverse culinary, medicinal, and ornamental applications. The study of cytogenetics of Illicium can clarify various discrepancies and further elucidate chromosome numbers, ploidy, and chromosome and genome size evolution in this basal angiosperm lineage and provide basic information to guide plant breeding and improvement programs. The objectives of this study were to use flow cytometry and traditional cytology to determine chromosome numbers, ploidy levels, and relative genome sizes of cultivated Illicium. Of the 29 taxa sampled, including ≈11 species and one hybrid, 2C DNA contents ranged from 24.5 pg for Illicium lanceolatum to 27.9 pg for Illicium aff. majus. The genome sizes of Illicium species are considerably higher than other ANA grade lineages indicating that Illicium went through considerable genome expansion compared with sister lineages. The New World sect. Cymbostemon had a slightly lower mean 2C genome size of 25.1 pg compared with the Old World sect. Illicium at 25.9 pg, providing further support for recognizing these taxonomic sections. All taxa appeared to be diploid and 2n = 2x = 28, except for Illicium floridanum and Illicium mexicanum which were found to be 2n = 2x = 26, most likely resulting from dysploid reduction after divergence into North America. The base chromosome number of x = 14 for most Illicium species suggests that Illicium are ancient paleotetraploids that underwent a whole genome duplication derived from an ancestral base of x = 7. Information on cytogenetics, coupled with phylogenetic analyses, identifies some limitations, but also considerable potential for the development of plant breeding and improvement programs with this genus.

Download Full-text

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

Bothalia ◽

10.4102/abc.v27i1.661 ◽

1997 ◽

Vol 27 (1) ◽

pp. 75-82 ◽

Cited By ~ 1

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).

Download Full-text

Interspecific hybridization between diploid Fagopyrum esculentum and tetraploid F. homotropicum

Canadian Journal of Plant Science ◽

10.4141/p03-147 ◽

2005 ◽

Vol 85 (1) ◽

pp. 41-48 ◽

Cited By ~ 7

Author(s):

Yingjie Wang ◽

Rachael Scarth ◽

Clayton Campbell

Keyword(s):

Interspecific Hybridization ◽

Chromosome Numbers ◽

Dna Analysis ◽

Genetic Recombination ◽

Diploid Species ◽

Normal Growth ◽

Colchicine Treatment ◽

Chromosome Elimination ◽

Ploidy Levels

The wild diploid species Fagopyrum homotropicum (2n = 2x = 16) has been used for buckwheat improvement, but, prior to this study, the tetraploid form (2n = 4x = 32) had not been hybridized with the cultivated species F. esculentum. The objective of this study was to hybridize F. esculentum with tetraploid F. homotropicum to increase the genetic variability. Forty-one interspecific F1 hybrids were obtained through ovule rescue in vitro, with hybridity confirmed using morphological characters, chromosome numbers (2n = 3x = 24) and DNA analysis. The F1 plants were mainly sterile. However, seven seeds were set spontaneously on two hybrid plants, and a large number of seeds were obtained after colchicine treatment. The F2 plants were divided into two groups based on chromosome numbers and morphology. The first group was hexaploid plants (2n = 6x = 48) or hypohexaploid plants (2n = 44–46), partially fertile with “gigas” features including increased height, dark green leaves, and large seeds with thick seed hulls. The second group of plants was diploid (2n = 2x = 16) (one plant had 17 chromosomes), with normal growth and fertility, and a combination of characters from both parents, indicating that genetic recombination had occurred during chromosome elimination. The diploid group was superior to the hexaploid group for use in buckwheat breeding programs due to the desirable characters and the ease of crossing. This is the first report of interspecific hybridization using different ploidy levels in the Fagopyrum genus. Key words: Buckwheat (F. esculentum; F. homotropicum), interspecific hybridization, breeding, tetraploid, diploid, hexaploid, fertility

Download Full-text

Karyotype analysis, DNA content and molecular screening in Lippia alba (Verbenaceae)

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652011005000012 ◽

2011 ◽

Vol 83 (3) ◽

pp. 993-1006 ◽

Cited By ~ 18

Author(s):

Patrícia M.O. Pierre ◽

Saulo M. Sousa ◽

Lisete C. Davide ◽

Marco A. Machado ◽

Lyderson F. Viccini

Keyword(s):

Genetic Variation ◽

Dna Content ◽

Chromosome Numbers ◽

Rapd Markers ◽

Nuclear Dna ◽

Pollen Viability ◽

Flow Cytometric Analysis ◽

Nuclear Dna Content ◽

Ploidy Levels ◽

Lippia Alba

Cytogenetic analyses, of pollen viability, nuclear DNA content and RAPD markers were employed to study three chemotypes of Lippia alba (Mill.) (Verbenaceae) in order to understand the genetic variation among them. Different ploidy levels and mixoploid individuals were observed. This work comprises the first report of different chromosome numbers (cytotypes) in L. alba. The chromosome numbers of La2-carvone and La3-linalool chemotypes suggested that they are polyploids. Flow cytometric analysis showed an increase of nuclear DNA content that was not directly proportional to ploidy level variation. A cluster analysis based on RAPD markers revealed that La3-linalool shares genetic markers with La1-citral and La2-carvone. The analysis showed that the majority of genetic variation of La3-linalool could be a consequence of ixoploidy. ur data indicates that sexual reproduction aong those three chemotypes is unlikely and suggests the beginning of reproductive isolation. The results demonstrated that chromosome analysis, nuclear DNA content estimation and RAPD markers constitute excellent tools for detecting genetic variation among L. alba chemotypes.

Download Full-text

Chromosome Number, Ploidy Level, and Nuclear DNA Content in 23 Species of Echeveria (Crassulaceae)

Genes ◽

10.3390/genes12121950 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1950

Author(s):

Guadalupe Palomino ◽

Javier Martínez-Ramón ◽

Verónica Cepeda-Cornejo ◽

Miriam Ladd-Otero ◽

Patricia Romero ◽

...

Keyword(s):

Flow Cytometry ◽

Chromosome Number ◽

Ploidy Level ◽

Dna Content ◽

Chromosome Numbers ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Root Tips ◽

Ploidy Levels ◽

Dna Amounts

Echeveria is a polyploid genus with a wide diversity of species and morphologies. The number of species registered for Echeveria is approximately 170; many of them are native to Mexico. This genus is of special interest in cytogenetic research because it has a variety of chromosome numbers and ploidy levels. Additionally, there are no studies concerning nuclear DNA content and the extent of endopolyploidy. This work aims to investigate the cytogenetic characteristics of 23 species of Echeveria collected in 9 states of Mexico, analyzing 2n chromosome numbers, ploidy level, nuclear DNA content, and endopolyploidy levels. Chromosome numbers were obtained from root tips. DNA content was obtained from the leaf parenchyma, which was processed according to the two-step protocol with Otto solutions and propidium iodide as fluorochrome, and then analyzed by flow cytometry. From the 23 species of Echeveria analyzed, 16 species lacked previous reports of 2n chromosome numbers. The 2n chromosome numbers found and analyzed in this research for Echeveria species ranged from 24 to 270. The range of 2C nuclear DNA amounts ranged from 1.26 pg in E. catorce to 7.70 pg in E. roseiflora, while the 1C values were 616 Mbp and 753 Mbp, respectively, for the same species. However, differences in the level of endopolyploidy nuclei were found, corresponding to 4 endocycles (8C, 16C, 32C and 64C) in E. olivacea, E. catorce, E. juarezensis and E. perezcalixii. In contrast, E. longiflora presented 3 endocycles (8C, 16C and 32C) and E. roseiflora presented 2 endocycles (8C and 16C). It has been suggested that polyploidization and diploidization processes, together with the presence of endopolyploidy, allowed Echeveria species to adapt and colonize new adverse environments.

Download Full-text

Mitotic and meiotic studies on two species of Ocimum (Lamiaceae) and their F1 hybrids

Botanica Lithuanica ◽

10.1515/botlit-2017-0006 ◽

2017 ◽

Vol 23 (1) ◽

pp. 59-67 ◽

Cited By ~ 2

Author(s):

Johnson Ademola Idowu ◽

Matthew Oziegbe

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Interspecific Variation ◽

F1 Hybrids ◽

Root Tips ◽

Flower Buds ◽

Ploidy Levels ◽

Ocimum Species ◽

Karyotype Formula ◽

Standard Techniques

AbstractOcimum L. species are important aromatic and medicinal plants. Many researchers have observed complexity in their chromosome numbers and ploidy levels. We studied the somatic and germline chromosomal features and behaviour of Ocimum basilicum L., two variants of O. canum Sims (‘c1’ and ‘c2’) and their F1hybrids. Chromosomes from root tips and flower buds were investigated using standard techniques; karyograms were formed and analysed. A chromosome number of 2n = 4x = 52 was observed in O. basilicum and O. canum ‘c1’ and their F1hybrid. One of the variants, O. canum ‘c2’ had a chromosome number of 2n = 2x = 24 and its intraspecific hybrid O. canum ‘c2’ × O. canum ‘c1’ had a chromosome number of 2n = 38. These Ocimum species and their F1hybrids showed different karyotype formula, but their chromosomes were mostly metacentric (174) and submetacentric (36) with few subtelocentric (8). Based on pairing configuration, O. basilicum is an allotetraploid plant, O. canum ‘c1’ is an autotetraploid plant and the O. canum ‘c1’ is a diploid. The F1 hybrids showed higher frequency of meiotic abnormalities than the parents. The study showed intraspecific and interspecific variation in chromosome numbers and pairing patterns, but the chromosomes of the Ocimum species were similar in their centromeric positions.

Download Full-text

Artificial whole genome duplication in paleopolyploid sturgeons yields highest documented chromosome number in vertebrates

Scientific Reports ◽

10.1038/s41598-020-76680-4 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Ievgen Lebeda ◽

Petr Ráb ◽

Zuzana Majtánová ◽

Martin Flajšhans

Keyword(s):

Chromosome Numbers ◽

Whole Genome Duplication ◽

Genome Duplication ◽

Mitotic Division ◽

Chromosome Count ◽

Whole Genome ◽

Acipenser Baerii ◽

Ploidy Levels ◽

Duplication Events ◽

C Value

AbstractCritically endangered sturgeons, having undergone three whole genome duplication events, represent an exceptional example of ploidy plasticity in vertebrates. Three extant ploidy groups, combined with autopolyploidization, interspecific hybridization and the fertility of hybrids are important issues in sturgeon conservation and aquaculture. Here we demonstrate that the sturgeon genome can undergo numerous alterations of ploidy without severe physiological consequences, producing progeny with a range of ploidy levels and extremely high chromosome numbers. Artificial suppression of the first mitotic division alone, or in combination with suppression of the second meiotic division of functionally tetraploid zygotes (4n, C-value = 4.15) of Siberian sturgeon Acipenser baerii and Russian sturgeon A. gueldenstaedtii resulted in progeny of various ploidy levels—diploid/hexaploid (2n/6n) mosaics, hexaploid, octoploid juveniles (8n), and dodecaploid (12n) larvae. Counts between 477 to 520 chromosomes in octoploid juveniles of both sturgeons confirmed the modal chromosome numbers of parental species had been doubled. This exceeds the highest previously documented chromosome count among vertebrates 2n ~ 446 in the cyprinid fish Ptychobarbus dipogon.

Download Full-text