DNA amplification, chromatin variations, and polytene chromosomes in differentiating cells of common bread wheat in vitro and roots of regenerated plants in vivo

Genome ◽  
1991 ◽  
Vol 34 (5) ◽  
pp. 799-809 ◽  
Author(s):  
Xiao Min Shang ◽  
Wen Chung Wang
Keyword(s):  
Triticum Aestivum ◽  
Cell Differentiation ◽  
Polytene Chromosomes ◽  
Dna Amplification ◽  
Root Tips ◽  
Embryogenic Calli ◽  
Double Minutes ◽  
Regenerated Plants ◽  
Giant Nuclei

Polytene chromosomes and giant nuclei were observed in differentiating cells of embryogenic calli and root tips of wheat plants (Triticum aestivum cv. Mustang) regenerated from long-term cell suspension cultures and selected cell lines after high-temperature stress. Many giant nuclei almost completely occupied the cellular space of the large parenchyma cells. The amount of DNA from the giant nuclei was as high as 174 C, equivalent to 3.03 × 104 pg of DNA, as revealed by Feulgen cytophotometry. Following cell differentiation, the giant nuclei that were endoaneupolyploid and polytene developed from interphase nuclei (aneuploid) and micronuclei. Polytene chromosomes from the B genome were tentatively identified by their banding patterns, as shown by the HCl–KOH–Giemsa banding method. Variations of polytene chromosomes were cable-like, dispersed, heterochromatinizated, or granulated at the different developmental stages. The number of granular chromatin particles in the cells was 85 to more than 300 when disintegration of the giant nuclei occurred. Some were exclusively heterochromatic, and many others consisted of both euchromatin and heterochromatin. The amount of DNA for these granular chromatin particles was estimated from 0.17 to 5.54 pg. Many minutes and double minutes existed in various stages of dividing and differentiating cells and accompanied the generation and disintegration of the giant nuclei. The DNA sizes of these minutes were estimated as 2.56 × 105 – 1.05 × 107 bp. These results suggested that DNA amplification, polytene chromosomes, minutes, and double minutes were induced in polyploid species with large chromosomes and maintained in embryogenic calli in vitro and apical segments of root tips of regenerated plants in vivo.Key words: giant nucleus, endoaneupolyploidy, polyteny, minutes and double minutes, cell differentiation, Triticum aestivum.

scholarly journals Optimization of in vitro regeneration protocol for a popular Indica rice (Oryza sativa L. cv Swarna)

2016 ◽  
Vol 5 (08) ◽  
pp. 1395 ◽  
Author(s):  
Vijaya Naresh Juturu ◽  
Gopala Krishna Mekala ◽  
Mallikarjuna Garladinne ◽  
Puli Chandra Obul Reddy ◽  
Akila Chandra Sekhar*
Keyword(s):  
Callus Induction ◽  
Oryza Sativa L ◽  
Indica Rice ◽  
In Vitro Regeneration ◽  
Regeneration System ◽  
Embryogenic Calli ◽  
Rice Varieties ◽  
Regenerated Plants ◽  
Rooting Medium

Though regeneration system in rice has been very well established compare to other crop plants, the fact remains that, most of the indica rice varieties are still recalcitrant for regeneration and genetic transformation. Therefore, refinement of tissue culture protocol for generation of embryogenic calli and regeneration of the fertile plants from a single cell should be a pre requisite event for development of transgenic plants. Here, in this study we reported high frequency robust regeneration protocols for a popular Indica cultivar Swarna.Mature seeds were used as initial material as explants. Highest callus induction % was observed in MSCIMP medium containing 2.0 mg-1 2,4, D + 0.5 mg-1 Kn as phytohormonal combinations. In addition, maximum regeneration was observed in 2.0 mg-l KN + 0.5 mg-l NAA. Regenerated plants were shifted to rooting medium followed by polyhouse for hardening. The callus induction and regeneration reported in this study were well suited for transformation agronomical important genes or functional genomics studies.

Stability of ploidy in meristems of plants regenerated from anther calli of wheat (Triticum aestivum L. em. Thell.)

Genome ◽  
1989 ◽  
Vol 32 (6) ◽  
pp. 1068-1073 ◽  
Author(s):  
Dalia T. Kudirka ◽  
Gideon W. Schaeffer ◽  
P. Stephen Baenziger
Keyword(s):  
Triticum Aestivum ◽  
Seed Set ◽  
Wheat Cultivar ◽  
Triticum Aestivum L ◽  
Root Tips ◽  
Winter Wheat Cultivar ◽  
Reproductive Structures ◽  
Regenerated Plants ◽  
Cell Genome ◽  
Individual Root

Plants were regenerated from anther calli of the winter wheat cultivar 'Centurk' (Triticum aestivum L. em. Thell.). Cells of root tips of young regenerated plants were assayed for ploidy and plants were categorized as polyhaploid, mixoploid, or hexaploid. Tillering and seed set were analyzed in plants that survived to maturity. Less than 1% of the tiller population produced by polyhaploid plants set seed. In contrast, 73% of the tiller population produced by hexaploid plants set seed, with significantly greater seed set per fertile tiller. These data were taken to indicate that the ploidy composition of root tips of young regenerated plants reflected that of the reproductive structures of mature regenerated plants. Common patterns of aneuploidy in hexaploid and hyperploid cells found among roots of individual plants confirmed the idea that doubling of the cell genome occurred before plant regeneration. Polyhaploid and hexaploid cells were found in individual root tips of mixoploid plants regenerated from calli that were known to be cytochimeric. The possibility that regeneration of plants can occur from more than a single cell of an anther callus is discussed.Key words: anther culture, Triticum aestivum, wheat, mixoploidy, aneuploidy, regeneration.

scholarly journals SOMACLONAL VARIATION IN SOLANUM AND LYCOPERSICON GENOTYPES.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1082a-1082
Author(s):  
Chang-Yeon Yu ◽  
John Masiunas
Keyword(s):  
Genotypic Variation ◽  
Lycopersicon Peruvianum ◽  
Root Tips ◽  
Greenhouse Soil ◽  
Shoot Height ◽  
Solanum Ptycanthum ◽  
Regenerated Plants ◽  
Two Generations ◽  
Mother Cells

The objective of this study was to investigate the chromosomal and genotypic variation in regenerated plants of Solarium and Lycopersicon. Calli of Lycopersicon peruvianum genotypes PI199380, PI126345, PI251301, and LA1373, along with Solanum ptycanthum were transferred onto media consisting of MS salts with Gamborg vitamins. The shoots formed were rooted in vitro and transferred to greenhouse soil. Actively growing root tips were harvested and pretreated, fixed, hydrolyses and stained. Pollen mother cells were fixed in propionic alcohol solution and stained with aceto-carmine. The number of chromosomes were counted. The greatest variation was in Solanum ptycanthum with chromosome numbers ranging from 18 to 60 (2n=24). Progeny analysis for 12 somaclones of Solarium ptycanthum was done by selfing for two generations. Morphology, shoot height, and weight were determined in each generation. The amount of variation differed among the somaclonal lines.

In-vitro- und In-vivo-Wirkung von Schilddrüsenhormon auf das Wachstum von Neuroblastomzellen

1990 ◽  
Vol 29 (03) ◽  
pp. 120-124
Author(s):  
R. P. Baum ◽  
E. Rohrbach ◽  
G. Hör ◽  
B. Kornhuber ◽  
E. Busse
Keyword(s):  
Cell Differentiation ◽  
Neuroblastoma Cells ◽  
Control Group ◽  
Initial Value ◽  
Initial Rise ◽  
Biphasic Effect ◽  
Contrast Microscopy ◽  
Morphological Sign

The effect of triiodothyronine (T3) on the differentiation of cultured neuroblastoma (NB) cells was studied after 9 days of treatment with a dose of 10-4 M/106 cells per day. Using phase contrast microscopy, 30-50% of NB cells showed formation of neurites as a morphological sign of cellular differentiation. The initial rise of the mitosis rate was followed by a plateau. Changes in cyclic nucleotide content, in the triphosphates and in the activity of the enzyme ornithine decarboxylase (ODC) were assessed in 2 human and 2 murine cell lines to serve as biochemical parameters of the cell differentiation induced by T3. Whereas the cAMP level increased significantly (3 to 7 fold compared with its initial value), the cGMP value dropped to 30 to 50% of that of the control group. ATP and GTP increased about 200%, the ODC showed a decrease of about 50%. The present studies show a biphasic effect of T3 on neuroblastoma cells: the initial rise of mitotic activity is followed by increased cell differentiation starting from day 4 of the treatment.

Long-term in vitro Storage Technique of Valuable Birch Genotypes and Plant Production on its Basis

2019 ◽  
pp. 57-67
Author(s):  
T.M. Tabatskaya ◽  
N.I. Vnukova
Keyword(s):  
Plant Production ◽  
High Survival ◽  
Ex Vitro ◽  
Regenerative Capacity ◽  
In Vitro Storage ◽  
Interspecific Differences ◽  
Regenerated Plants ◽  
Growing Conditions

A technique for the long-term (up to 27 years) in vitro storage of valuable birch genotypes under normal (25 °C, 2.0 klx, 16-h day and 8-h night) and low temperature (4 °C, 0.5 klx, 6-h day and 18-h night) growing conditions on hormone-free media has been described. The study explored for the first time the influence of different strategies to store the clones of Betula pubescens and B. pendula var. сarelica (6 genotypes) on the regenerative capacity of collection samples, adaptive potential of regenerated plants and plant production by the in vitro and ex vitro techniques. It was established that both storage strategies provided a persistently high survival rate (82-100%) and regenerative capacity of in vitro shoots (the multiplication coefficient of 4.2-6.3 and rhizogenic activity of 90-100%). The clones retained their characteristics of height growth under the in vitro and ex vitro conditions, and demonstrated intraclonal homogeneity and lack of signs of somaclonal variability. The plants showed substantial interspecific differences at the stage of multiplication and transfer to the greenhouse. The highest percentage of acclimated plants (75-98% depending on the clone genotype) was obtained after planting of micro plants straight in the greenhouse, which simplified the technology and made plant production less costly. long-term in vitro storage, birch, species, genotype, micropropagation, ex vitro adaptation, plant material

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