Cytogenetics of a synthesized allopentaploid (2n = 5x = 100) in the genus Glycine subgenus Glycine

Genome ◽  
1991 ◽  
Vol 34 (5) ◽  
pp. 751-756 ◽  
Author(s):  
R. J. Singh ◽  
T. Hymowitz
Keyword(s):  
Chromosome Pairing ◽  
Morphological Traits ◽  
Colchicine Treatment ◽  
Close Similarity ◽  
Breeding Behavior ◽  
A Genome ◽  
Origin Identification

The objectives of this study were to provide information on the origin, identification, meiosis, and breeding behavior of a synthesized allopentaploid (2n = 5x = 100) in the genus Glycine (Willd.) subgenus Glycine. The origin of the pentaploid plant was as follows: G. clandestina, 2n = 2x = 40, A1A1 × G. canescens, 2n = 2x = 40, AA (designated as H119), F1 (2n = 2x = 40, AA1) × G. tomentella (2n = 4x = 80, AxAxDD) → F1 (2n = 3x = 60, AAxD (assuming A-genome chromosomes from G. canescens were transmitted)) → 0.1% colchicine treatment → 2n = 6x = 120 (AAAxAxDD) × G. tomentella (2n = 4x = 80, AxAxDD) → BC1, 2n = 5x = 100 (AAxAxDD). Morphologically, the pentaploid plant very closely resembled the tetraploid G. tomentella, PI 441005. Compared with hexaploids, the pentaploid plant was less vigorous for several morphological traits. However, it was not possible to distinguish visually among 4x, 5x, and 6x plants. Intergenomic chromosome pairing was followed in hexaploid (A–A, Ax–Ax, D–D) and pentaploid (A, Ax–Ax, D–D) plants. Despite a close similarity between A and Ax genomes (A- and Ax-genome chromosomes pair normally in the absence of their homologues) meiotic stages were highly abnormal in the pentaploid, with univalents, laggards, and micronuclei, but the plant set normal pods and seeds. The pentaploid plant did not breed true, as chromosomes in the 14 examined plants of the progeny ranged from 2n = 86 to 97. Furthermore, progeny of a plant with 2n = 90 segregated for plants with 2n = 81–86. These results indicate that the preferential elimination of G. canescens (A genome) chromosomes is rapid and eventually AxAxDD genome chromosomes will prevail. Thus, pentaploids will stabilize at the tetraploid level.Key words: Glycine spp., allopolyploidy, chromosome pairing, genome.

Putative diploid ancestors of 80-chromosome Glycine tabacina

Genome ◽  
1992 ◽  
Vol 35 (1) ◽  
pp. 140-146 ◽  
Author(s):  
R. J. Singh ◽  
K. P. Kollipara ◽  
F. Ahmad ◽  
T. Hymowitz
Keyword(s):  
Adventitious Roots ◽  
Chromosome Doubling ◽  
Colchicine Treatment ◽  
Meiotic Pairing ◽  
B Genome ◽  
Specific Hybridization ◽  
A Genome ◽  
Genome Homology ◽  
Glycine Tabacina ◽  
Natural Mutation

The objective of this study was to discover the diploid progenitors of 80-chromosome Glycine tabacina with adventitious roots (WAR) and no adventitious roots (NAR). Three synthetic amphiploids were obtained by somatic chromosome doubling. These were (i) (G. latifolia, 2n = 40, genome B1B1,) × (G. microphylla, 2n = 40, genome BB) = F1(2n = 40, genome BB1) – 0.1% colchicine treatment (CT) – 2n = 80, genome BBB1B1; (ii) (G. canescens, 2n = 40, genome AA) × G. microphylla, 2n = 40, genome BB) = F1 (2n = 40, genome AB) – (CT) – 2n = 80, genome AABB; (iii) (G. latifolia, 2n = 40, B1B1) × G. canescens, 2n = 40, AA) = F1 (2n = 40, genome AB1) – (CT) – 2n = 80, genome AAB1B1. The segmental allotetraploid BBB1B1 was morphologically similar to the 80-chromosome G. tabacina (WAR), but meiotic pairing data in F1 hybrids did not support the complete genomic affinity. Despite normal diploid-like meiosis in allotetraploids AABB and AAB1B1, AABB was completely fertile, while pod set in AAB1B1 was very sparse. Morphologically, allotetraploid AABB was indistinguishable from the 80-chromosome G. tabacina (NAR) but in their F1 hybrids, the range of univalents at metaphase I was wide (4–44). The allotetraploid AAB1B1 did not morphologically resemble the 80-chromosome G. tabacina (NAR). However, the F1 hybrid of AABB × AAB1B1 showed normal meiosis with an average chromosome association (range) of 1.7 I (0–4) + 39.2 II (38–40). Based on this information, we cannot correctly deduce the diploid progenitor species of the 80-chromosome G. tabacina (NAR). The lack of exact genome homology may be attributed to the geographical isolation, natural mutation, and growing environmental conditions since the inception of 80-chromosome G. tabacina. Thus, it is logical to suggest that the 80-chromosome G. tabacina (NAR) is a complex, probably synthesized from A genome (G. canescens, G. clandestina, G. argyrea, G. tomentella D4 isozyme group) and B genome (G. latifolia, G. microphylla, G. tabacina) species, and the 80-chromosome G. tabacina (WAR) complex was evolved through segmental allopolyploidy from the B genome species.Key words: Glycine spp., allopolyploidy, colchicine, genome, intra- and inter-specific hybridization, polyploid complex.

GENETIC REGULATION OF HETEROGENETIC CHROMOSOME PAIRING IN POLYPLOID SPECIES OF THE GENUS TRITICUM sensu lato

1982 ◽  
Vol 24 (1) ◽  
pp. 57-82 ◽  
Author(s):  
Patrick E. McGuire ◽  
Jan Dvořák
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Chinese Spring ◽  
Genetic Regulation ◽  
Triticum Aestivum L ◽  
Polyploid Species ◽  
D Genome ◽  
Chromosome 5B ◽  
A Genome

Polyploid species of Triticum sensu lato were crossed with Triticum aestivum L. em. Thell. cv. Chinese Spring monotelodisomics or ditelosomics that were monosomic for chromosome 5B. Progeny from these crosses were either euploid, nullisomic for 5B, monotelosomic for a given Chinese Spring chromosome, or nullisomic for 5B and monotelosomic simultaneously. The Chinese Spring telosome in the hybrids permitted the evaluation of autosyndesis of chromosomes of the tested species. In addition, several Chinese Spring eu- and aneuhaploids were produced. Genotypes of T. cylindricum Ces., T. juvenale Thell., T. triunciale (L.) Raspail, T. ovatum (L.) Raspail, T. columnare (Zhuk.) Morris et Sears, T. triaristatum (Willd.) Godr. et Gren., and T. rectum (Zhuk.) comb. nov. were all shown to have suppressive effects on heterogenetic pairing in hybrids lacking 5B or 3AS, whereas T. kotschyi (Boiss.) Bowden had no effect. It was concluded that diploid-like meiosis in these species is due to genetic regulation. A number of these genotypes promoted heterogenetic pairing in the presence of 5B. A model is presented to explain this dichotomous behavior of the tested genotypes. Monotelosomic-3AL haploids had a greater amount of pairing than did euhaploid Chinese Spring, which substantiated the presence of a pairing suppressor(s) on the 3AS arm. Evidence is presented that shows that T. juvenale does not have a genome homologous with the D genome of T. aestivum.

A AND B GENOME HOMOEOLOGIES IN TETRAPLOID AND OCTOPLOID CYTOTYPES OF BROMUS INERMIS

1979 ◽  
Vol 21 (1) ◽  
pp. 65-71 ◽  
Author(s):  
K. C. Armstrong
Keyword(s):  
Chromosome Pairing ◽  
Convincing Evidence ◽  
Bromus Inermis ◽  
Open Pollination ◽  
Homoeologous Chromosome ◽  
Genome Chromosome ◽  
B Genome ◽  
Homoeologous Chromosome Pairing ◽  
A Genome ◽  
Structural Differences

Homoeology between the A and B genomes of allotetraploid (2n = 4x = 28) AiAiBiBi and autoallooctoploid (2n = 8x = 56) AIAIAIAIBIBIBIBI cytotypes of B. inermis Leyss. was studied in a tetraploid F1 hybrid (AeAeAiBi) from 4x B. erectus × 4x B. inermis and in a haplo-triploid (AIeAIeBI) which occurred spontaneously in the F2 from open-pollination among plants of the hexaploid F1 hybrid (AeAeAIAIBIBI) from 4x B. erectus × 8x B. inermis. Chromosome pairing at metaphase I in both the tetraploid (AeAeAiBi) and haplo-triploid (AIeAIeBI) indicated that for each A genome chromosome there was a corresponding B genome homoeologue. There was no convincing evidence of gross structural differences between the two homoeologous genomes. The frequency of trivalent formation in the haplo-triploid was approximately one-half that found in two pentaploids (2n = 5x = 35) AIeAIeAIBIBI. This indicates that the pairing affinity between the A and B genomes is one-half that between homologues as expressed by trivalent formation in triploids of the type AAB and AAA. Homoeologous chromosome pairing (A with B) may be controlled by a gene which is hemizygous ineffective.

Phylogenetic relationships of species of genus Arachis based on genic sequences

Genome ◽  
2014 ◽  
Vol 57 (6) ◽  
pp. 327-334 ◽  
Author(s):  
Guohao He ◽  
Noelle A. Barkley ◽  
Yongli Zhao ◽  
Mei Yuan ◽  
C.S. Prakash
Keyword(s):  
South America ◽  
Phylogenetic Relationships ◽  
Morphological Traits ◽  
Single Copy ◽  
D Genome ◽  
A Genome ◽  
Cross Compatibility ◽  
Single Clade ◽  
Basal Clade ◽  
Cultivated Peanut

The genus Arachis (Fabaceae), which originated in South America, consists of 80 species. Based on morphological traits and cross-compatibility among the species, the genus is divided into nine taxonomic sections. Arachis is the largest section including the economically valuable cultivated peanut (A. hypogaea). Seven genic sequences were utilized to better understand the phylogenetic relationships between species of genus Arachis. Our study displayed four clades of species of Arachis. Arachis triseminata was genetically isolated from all other species of Arachis studied, and it formed the basal clade with A. retusa and A. dardani from the most ancient sections Extranervosae and Heteranthae, respectively. Species of section Arachis formed a separated single clade from all other species, within which species having B and D genome clustered in one subgroup and three species characterized with an A genome grouped together in another subgroup. A divergent clade including species from five sections was sister to the clade of section Arachis. Between the sister clades and the basal clade there was a clade containing species from the more advanced sections. Phylogenetic relationships of all the species of Arachis using multiple genic sequences were similar to the phylogenies produced with single-copy genes.

Genetic and cytogenetic analyses of the A genome of Triticum monococcum. I. Cytology, breeding behaviour, fertility, and morphology of induced autotetraploids

1985 ◽  
Vol 27 (1) ◽  
pp. 51-63 ◽  
Author(s):  
J. Kuspira ◽  
R. N. Bhambmani ◽  
T. Shimada
Keyword(s):  
Decisive Role ◽  
Leaf Size ◽  
Kernel Weight ◽  
Triticum Monococcum ◽  
Fertility Level ◽  
Breeding Behavior ◽  
Diploid Progenitor ◽  
Artificial Medium ◽  
A Genome ◽  
Cytogenetic Analyses

Autotetraploids were colchicine-induced in Triticum monococcum and, upon comparison to their diploid progenitor, possessed the following characteristics: (i) their cells were on the average 20.8% larger; (ii) plant height was reduced by 15% and tillering by 37.5%; (iii) spikes, 1000-kernel weight, pistil size (length (L)/weight (W), and leaf size (L/W) were 53.9, 51.2, 80/57.1, and 60/26.4% larger, respectively; and (iv) they were 12.4% earlier in heading. Observed mean numbers of univalents, bivalents, trivalents (linear, convergent, and indifferent coorientations), and quadrivalents (convergent and parallel alignments only) per microsporocyte at metaphase I were 0.62, 9.86, 0.23, and 1.74, respectively; 65.4% of all meiocytes possessed bivalents and (or) quadrivalents and produced balanced meiotic products; 34.6% also possessed univalents and (or) trivalents and, therefore, produced balanced and unbalanced meiotic products. The actual 70.9% balanced meiotic products falls within the calculated range of 65.4–81.3%. Our tetraploids breed true. Evidence and reasons for this are discussed. The fertility of our tetraploids was high (79.8%). Irregular chromosome behaviour during meiosis may play a decisive role in determining the fertility level. Genic factors may also be involved. Methods of improving fertility and whether chromosomal factors alone are responsible for tetraploid fertility levels are discussed. Mature seed from reciprocal 2n = 4x × 2n = 2x crosses was shrivelled because of endosperm collapse and did not germinate. Thus, embryo excision and culturing on artificial medium was required to obtain viable autotriploids.Key words: Triticum monococcum, autotetraploid, cytology, breeding behavior, fertility, morphology.

Cytology and breeding behavior of interspecific hybrids and induced amphiploids of Zinnia elegans and Zinnia angustifolia

1984 ◽  
Vol 26 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Veronica M. Terry-Lewandowski ◽  
Gary R. Bauchan ◽  
Dennis P. Stimart
Keyword(s):  
Disease Resistance ◽  
Interspecific Hybrids ◽  
Colchicine Treatment ◽  
Zinnia Elegans ◽  
Breeding Behavior ◽  
Contributing Factors ◽  
Zinnia Angustifolia ◽  
Partial Homology ◽  
Partial Fertility ◽  
Homoeologous Chromosomes

Cytological studies were performed on interspecific hybrids and induced amphiploids of Zinnia angustifolia HBK (2n = 22) and Zinnia elegans Jacq. (2n = 24) to ascertain their potential in serving as intermediaries in the transfer of genes for disease resistance. Partial fertility was restored in sterile F1 hybrids (2n = 23) through colchicine treatment of axillary buds. Lagging univalents and irregular distribution of chromosomes to the gametes were the major contributing factors to the sterility observed among the F1 hybrids. Bivalent associations in the F1 indicated partial homology between parental genomes. The induced amphiploids (2n = 46) formed predominantly bivalents at metaphase I owing to the suppression of pairing between homoeologous chromosomes. Consequently, these segmental allopolyploids resembled diploids in their cytological and genetic behavior and bred true to their intermediate condition with little or no segregation in later generations. It is postulated that the gene(s) controlling chromosome pairing is derived from Z. elegans. The cytological and genetic performance of colchicine-induced amphiploids of Z. elegans and Z. angustifolia suggest considerable potential for the improvement of Z. elegans cultivars with respect to disease resistance and the immediate stabilization of characters through genetic uniformity.

Hypertriploid in Soybean: Origin, Identification, Cytology, and Breeding Behavior

Crop Science ◽  
2000 ◽  
Vol 40 (1) ◽  
pp. 72-77 ◽  
Author(s):  
S. J. Xu ◽  
R. J. Singh ◽  
K. P. Kollipara ◽  
T. Hymowitz
Keyword(s):  
Breeding Behavior ◽  
Origin Identification

Segregation by morphological analyses of trisomy types in Lotus tenuis (Fabaceae)

1997 ◽  
Vol 75 (8) ◽  
pp. 1209-1214 ◽  
Author(s):  
Pierre St.-Marseille ◽  
William F. Grant
Keyword(s):  
Key Words ◽  
Morphological Traits ◽  
Colchicine Treatment ◽  
Phenotypic Traits ◽  
Morphological Comparison ◽  
Primary Trisomics ◽  
Lotus Tenuis

Two autotetraploids (2n = 4x = 24) were produced by colchicine treatment of dry seeds of Lotus tenuis Waldst. et Kit. Triploids (2n = 3x = 18) were obtained by backcrossing the tetraploids to normal diploid plants. Primary trisomies (2n = 12 + 1) were obtained by selfing the triploids. A morphological comparison was made between a randomly selected diploid, a tetraploid, and five trisomic plants. The trisomics could be distinguished distinctly from the diploid and tetraploid using 12 quantitative phenotypic traits. Two traits, bract index and number of flowers per umbel, were not significantly different between all three cytotypes (2x, 2x + 1, 4x). By means of morphological analyses it was possible to select trisomic plants for presumably different trisomes prior to detailed cytological analyses of individual chromosomes. Key words: aneuploidy, tetraploids, Fabaceae, Lotus tenuis, morphological traits, triploids, primary trisomics.

Chromosome pairing in triploid and tetraploid hybrids in Elytrigia (Triticeae; Poaceae)

1984 ◽  
Vol 26 (5) ◽  
pp. 519-522 ◽  
Author(s):  
Patrick E. McGuire
Keyword(s):  
Chromosome Pairing ◽  
Genome Analysis ◽  
Triploid Hybrid ◽  
Pollen Mother Cells ◽  
Tetraploid Hybrid ◽  
A Genome ◽  
Mother Cells ◽  
Metaphase I

Mean chromosome pairing of 5.14I + 1.28II (rod) + 3.86II (ring) + 1.47III + 0.11IV (open) + 0.11V was observed in pollen mother cells at metaphase I in the triploid hybrid Elytrigia scirpea (K. Presl) Holub, 2n = 4x = 28 × E. bessarabica (Savul. et Rayss) Dubrovik, 2n = 4x = 14. Mean chromosome pairing of 3.71I + 2.29II (rod) + 1.82II (ring) + 2.64III + 0.29IV (open) was observed in the triploid hybrid E. curvifolia (Lange) Holub, 2n = 4x = 28 × E. bessarabica. Mean chromosome pairing of 3.00I + 0.93II (rod) + 1.57II (ring) + 1.36III + 1.79IV (open) + 1.I4IV (closed) + 0.79V was observed in the tetraploid hybrid E. junceiformis Löve et Löve, 2n = 4x = 28 × E. curvifolia. The first hybrid provides the first evidence by genome analysis that E. bessarabica possesses a genome (designated Eb) which is closely related to the genomes of E. scirpea (ES and ESC) and hence to the E genome of E. elongata (Host) Nevski, 2n = 2x = 14. The second and third hybrids provide the first evidence that the two genomes of E. curvifolia (designated EC and ECU) are related to the Eb genome of E. bessarabica and thus to the E genome of E. elongata.Key words: Elytrigia, homoeology, Triticum, phylogeny, triploid, tetraploid.

scholarly journals Artificially Induced Polyploidization in Lobularia maritima (L.) Desv. and Its Effect on Morphological Traits

HortScience ◽  
2015 ◽  
Vol 50 (5) ◽  
pp. 636-639 ◽  
Author(s):  
Renwei Huang ◽  
Daofeng Liu ◽  
Min Zhao ◽  
Zhineng Li ◽  
Mingyang Li ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Efficient Method ◽  
Morphological Traits ◽  
Stomatal Density ◽  
Morphological Characteristics ◽  
Colchicine Treatment ◽  
Ornamental Plant ◽  
Lobularia Maritima ◽  
Ornamental Traits ◽  
Germinating Seeds

Lobularia maritima (L.) Desv. is an important ornamental plant. We investigated an efficient method to induce tetraploid plants of L. maritima (L.) Desv. by treating germinating seeds and apical growing points of seedlings with a range of concentrations of colchicine for different periods of time. Examination of the ploidy level by counting chromosome numbers at metaphase confirmed that the chromosome number of diploid plants was 2n = 2x = 24, whereas 2n = 4x = 48 was observed in tetraploid plants. The morphological characteristics of the diploid and colchicine-induced tetraploid plants were compared. Increases in the size of leaves, flowers, and stomata were observed in the tetraploid plants compared with the diploids. However, the stomatal density and plant height of the tetraploid plants were lower than for the diploid plants. This study presents the first report of autotetraploid plants of L. maritima (L.) Desv., and of the successful generation of tetraploid plants with improved ornamental traits by colchicine treatment.

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