scholarly journals Frequency, Spectrum, and Stability of Leaf Mutants Induced by Diverse γ-Ray Treatments in Two Cymbidium Hybrids

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 546
Author(s):  
Sang Hoon Kim ◽  
Se Won Kim ◽  
Joon-Woo Ahn ◽  
Jaihyunk Ryu ◽  
Soon-Jae Kwon ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Mutation Frequency ◽  
Leaf Shape ◽  
Mutation Breeding ◽  
Mutation Induction ◽  
Limited Information ◽  
Γ Irradiation ◽  
Γ Ray ◽  
The Stability

Ionizing radiation combined with in vitro tissue culture has been used for development of new cultivars in diverse crops. The effects of ionizing radiation on mutation induction have been analyzed on several orchid species, including Cymbidium. Limited information is available on the comparison of mutation frequency and spectrum based on phenotypes in Cymbidium species. In addition, the stability of induced chimera mutants in Cymbidium is unknown. In this study, we analyzed the radiation sensitivity, mutation frequency, and spectrum of mutants induced by diverse γ-ray treatments, and analyzed the stability of induced chimera mutants in the Cymbidium hybrid cultivars RB003 and RB012. The optimal γ-irradiation conditions of each cultivar differed as follows: RB003, mutation frequency of 4.06% (under 35 Gy/4 h); RB012, 1.51% (20 Gy/1 h). Re-irradiation of γ-rays broadened the mutation spectrum observed in RB012. The stability of leaf-color chimera mutants was higher than that of leaf-shape chimeras, and stability was dependent on the chimera type and location of a mutation in the cell layers of the shoot apical meristem. These results indicated that short-term γ-irradiation was more effective to induce mutations in Cymbidium. Information on the stability of chimera mutants will be useful for mutation breeding of diverse ornamental plants.

scholarly journals Mutation induction of EMS and 60Co γ irradiation in vitro cultured seedlings of red pulp pitaya (Stenocereus) and ISSR analyzing of mutant

2020 ◽  
Author(s):  
Renju Deng ◽  
Jianxin Fan ◽  
Yongqing Wang ◽  
Tao Liu ◽  
Jifen Jin
Keyword(s):  
Dose Range ◽  
Lethal Dose ◽  
Morphological Characteristics ◽  
Mutation Breeding ◽  
Genetic Distances ◽  
Mutation Induction ◽  
Γ Irradiation ◽  
Speed Up ◽  
Red Pulp

Abstract Background Pitaya is a new type of fruit tree developed vigorously in recent years in China. The current variety characteristics of pitaya can not meet the needs of market development. In order to speed up the breeding process and increase the variation frequency, the red pulp pitaya variety 'Zi Honglong' seedlings in vitro were used as experimental materials, which were treated with different dose of ethyl methanesulfonate (EMS) and 60Co γ irradiation, respectively. Results The results indicated that the appropriate concentration for the EMS mutagenesis was 3.71%-3.95%, and the optimum time was 8.26–9.32 h. The feasible irradiation dose range for 60Co γ mutation was 38.5–42.4 Gy. The dose of mutagens was inversely proportional to the survival and differentiation rate of seedlings. By observing the morphological characteristics of mutagenic materials, 14 mutants were screened out. According to the ISSR analysis, a total of 67 bands were amplified from the 9 primers, among which 71.64% polymorphism was obtained. Compared with the control, there was a specific band in No. 5 mutant detected by primer M06, but its functional characteristics needed further research and verification. The genetic distances (GD) among the tested materials were 0.0120 to 0.4169 analyzed by NTSYS pc 2.1. The UPGMA clustering analysis demonstrated that 15 germplasm could be divided into 6 groups at a cutpoint of genetic distance 0.11, and among them No. 5, 6, 10, 12 and 14 warranted separate categorization, which showed that they had more differences in tested germplasm. Conclusions It concluded that pitaya mutant might be produced regardless of the mutagenic dose high or low, and a higher dose could increase the frequency of variation. In this study, critical dose and half lethal dose can be used as the appropriate dose for mutation breeding of pitaya. Additional, molecular analysis showed that there was a certain difference between the mutant plants and the control. It needs to be further verified whether this difference was a physiological variation or a real variation due to the randomness of mutation, so as to lay a foundation for better carrying out mutation breeding of pitaya.

scholarly journals In Vitro Mutagenesis of Etlingera elatior by Gamma Ray Intermittent Irradiation

2018 ◽  
Vol 5 (3) ◽  
pp. 111-118 ◽  
Author(s):  
Elmi Irmayanti Azzahra ◽  
Syarifah Iis Aisyah ◽  
Diny Dinarti ◽  
Krisantini Krisantini
Keyword(s):  
Gamma Ray ◽  
Morphological Changes ◽  
Leaf Shape ◽  
Morphological Diversity ◽  
Mutation Breeding ◽  
Ornamental Plant ◽  
In Vitro Mutagenesis ◽  
Split Dose ◽  
Etlingera Elatior

Etlingera elatior is tropical ornamental plant commonly called “torch ginger” from Zingiberaceae family. Conventional breeding of E. elatior is limited by cross incompatibility, poor fruit set and low seed production.  In this study irradiation of E. elatior with Gamma ray performed to induce mutation. This study was aimed to increase morphological diversity and to obtain unique morphological characters to increase the aesthetic value of E. elatior as ornamental plants and cut flower. Two genotypes of E. elatior, red and white flowers, were tested. The LD20, LD35, and LD50 were determined following intermittent (split dose) Gamma irradiation with a two-hour gap between each gamma ray shot. Red genotype E. elatior explants were irradiated with dose of 3 + 3 Gy (LD20); 4 + 4 Gy (LD35) and 5 + 5 Gy (LD50); white genotype were irradiated with a dose of 2 + 2 Gy (LD20); 2.8 + 2.8 Gy (LD35) and 3.7 + 3.7 Gy (LD50). Non-irradiated explants were set as control.  The results of this study indicated that the increase in dose of gamma ray irradiation changed shoot length and number of leaves in the red genotype per explant as compared to control. Morphological changes occurred in leaf shape at 5 + 5 Gy and 3.7 + 3.7 Gy and formation of variegated leaves at 2.8 + 2.8 Gy and 5 + 5 Gy. Keywords: mutation breeding, ornamental plant, split irradiation dose, torch ginger, Zingiberaceae

Radioprotection of 1,2-dimethylhydrazine-initiated colon cancer in rats using low-dose γ rays by modulating multidrug resistance-1, cytokeratin 20, and β-catenin expression

2015 ◽  
Vol 35 (3) ◽  
pp. 282-292 ◽  
Author(s):  
HM Nabil ◽  
BN Hassan ◽  
AA Tohamy ◽  
HF Waaer ◽  
AE Abdel Moneim
Keyword(s):  
Colon Cancer ◽  
Multidrug Resistance ◽  
Ionizing Radiation ◽  
Tumor Cells ◽  
Low Dose ◽  
Colorectal Tumor ◽  
Cytokeratin 20 ◽  
Γ Irradiation ◽  
Γ Rays ◽  
Γ Ray

Ionizing radiation is a widely used therapy for solid tumors. However, high-dose ionizing radiation causes apoptosis, transforms normal cells into tumor cells, and impairs immune functions, leading to the defects in the removal of damaged or tumor cells. In contrast, low-dose radiation has been reported to exert various beneficial effects in cells. This experimental study investigated the effect of γ rays at low dose on the development of colorectal tumor in a 1,2-dimethylhydrazine (DMH)-induced colon cancer. Colorectal tumor model was induced in Wistar rats by subcutaneous injection of DMH (20 mg/kg) once a week for 15 weeks. Starting from zero day of DMH injection, a single low dose of whole-body γ irradiation of 0.5 Gy/week was applied to the rats. A significant reduction in lipid peroxidation, nitric oxide, and elevation in the glutathione content and antioxidant enzyme activity (superoxide dismutase and catalase) were observed after γ irradiation comparing with DMH group. Moreover, γ ray reduced the expressions of multidrug resistance 1 (MDR1), β-catenin, and cytokeratin 20 (CK20) those increased in DMH-treated rats. However, survivin did not change with γ ray treatment. A histopathological examination of the DMH-injected rats revealed ulcerative colitis, dysplasia, anaplasia, and hyperchromasia. An improvement in the histopathological picture was seen in the colon of rats exposed to γ rays. In conclusion, the present results showed that low-dose γ ray significantly inhibited DMH-induced colon carcinogenesis in rats by modulating CK20, MDR1, and β-catenin expression but not survivin expression.

scholarly journals Morphological and anatomical features of narrow-leaved lavender plants with prolonged conservation under in vitro genebank

2020 ◽  
Vol 24 ◽  
pp. 00015
Author(s):  
Valentina Brailko ◽  
Natalya Ivanova ◽  
Irina Zhdanova ◽  
Olga Mitrofanova
Keyword(s):  
Leaf Shape ◽  
Wild Plant ◽  
Prolonged Storage ◽  
Vascular Bundles ◽  
Anatomical Features ◽  
Wild Plant Species ◽  
Functional Features ◽  
The Stability

Optimization of plants long-term conservation under in vitro conditions and identification of their structural and functional features during preservation is the basis for the creation of a genebank of cultured and wild plant species in vitro. The aim of our work was to study morphological and anatomical features of plants in lavender cultivar ‘Sineva’ after two years of in vitro storage at low positive temperatures. The plant material was evaluated after 24 months of conservation. A significant decrease in the linear parameters of leaves in the preserved plants was noted. Leaf shape altered from narrowly linear to oblong. With prolonged storage, the thickness of the leaf blade slightly increased. The integumentary tissues were thinner, compared with the plants cultured under standard in vitro conditions, the cuticle was not clear. The number of stomata decreased. The number of small vascular bundles decreased. The obtained data demonstrate viability of in vitro preserved explants, despite significant differences in structure, preservation of chlorophyll-containing tissues, a decrease in transpiration, and an increase of trichomes number. The stability of the vegetative organs functioning was revealed.

scholarly journals Nuclear DNA content as an indicator of inflorescence colour stability of in vitro propagated solid and chimera mutants of chrysanthemum

2020 ◽  
Vol 143 (2) ◽  
pp. 421-430 ◽  
Author(s):  
Natalia Miler ◽  
Dariusz Kulus ◽  
Elwira Sliwinska
Keyword(s):  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Γ Irradiation ◽  
Periclinal Chimera ◽  
Single Node ◽  
Periclinal Chimeras ◽  
Fcm Analysis ◽  
The Stability

Abstract In chrysanthemum, breeders seek for desirable characteristics of the inflorescence, which can first be established once the plant is mature. The present study aims to determine whether measurement of DNA content can be useful in the detection of somaclonal variants and/or separation of chimera components in chrysanthemum at the early in vitro multiplication stage. Eleven Chrysanthemum × morifolium (Ramat.) Hemsl. cultivars of the Lady group (a mother cultivar and ten of its radiomutants obtained by X-ray- or γ-irradiation; solid and periclinal chimeras) were propagated in vitro. Single-node explants were cultured in Murashige and Skoog (MS) medium, either without plant growth regulators (PGRs) or supplemented with 6-benzyladenine (BA) and indole-3-acetic acid (IAA). The nuclear DNA content was measured by flow cytometry (FCM) in the shoots produced in vitro. After acclimatization and growth of the plants in a glasshouse, inflorescence colour was recorded. The addition of PGRs to the medium almost doubled the mean number of shoots produced in vitro per explant, but caused a change in inflorescence colour of all (‘Lady Apricot’; periclinal chimera) or part of the plants (‘Lady Amber’; solid mutant and ‘Lady Salmon’; periclinal chimera). All radiomutants contained less DNA than the mother cultivar ‘Richmond’. There were significant differences in DNA content between plants of the same cultivar grown in media with or without PGRs for ‘Lady Apricot’ and ‘Lady Salmon’, but no phenotype alternation occurred in chrysanthemums produced in PGR-free medium compared to the original cultivars. Conversely, in medium with PGRs, chimeras produced flowers different from the original colour. In all except one cultivar (‘Lady Amber’; solid mutant) a lack of differences in genome size between plants grown in either medium coincided with a stable inflorescence colour. The occurrence of some plants of ‘Lady Amber’ with different inflorescence colour may be due to small DNA changes, undetectable by FCM. It can be concluded that FCM analysis of DNA content in young plantlets can be indicative of the stability of inflorescence colour in chrysanthemum, especially chimeric cultivars, and for mutant detection.

Mutagenesis of in vitro explants of Coffea spp. to induce fungal resistance.

2021 ◽  
pp. 344-352
Author(s):  
Souleymane Bado ◽  
Fatemeh Maghuly ◽  
Vitor Varzea ◽  
Margit Laimer
Keyword(s):  
Tissue Culture ◽  
Embryogenic Callus ◽  
Mutation Breeding ◽  
Climatic Conditions ◽  
Fungal Resistance ◽  
Mutation Induction ◽  
Tree Crops ◽  
Culture Techniques ◽  
Cell Tissue

Abstract Coffee is one of the most valuable commodity tree crops worldwide. However, it suffers from several devastating diseases and pests, for example coffee leaf rust and coffee berry borer, whose impact is being amplified by changing climatic conditions. Development of new adapted varieties remains a laborious effort by conventional breeding due to the long juvenile period in tree crops. Plant cell/tissue culture represents the ultimate method to produce large amounts of true-to-type healthy plants and of explants for mutation breeding. In fact, mutation induction combined with in vitro cell/tissue culture techniques has proved to be effective for developing improved cultivars of perennial crops. Prior to mutation breeding, cell and tissue radiosensitivity tests to various mutagens need to be performed, so that optimal treatments can be applied for large population development. Thus, different in vitro explants (plantlet, leaf, callus, embryogenic callus, globular and torpedo stage embryos) of Coffea arabica and Coffea canephora were exposed to different gamma-ray doses (0, 10, 15, 20, 40, 60 and 80 Gy). After 9-21 weeks incubation, a radiosensitivity test was conducted on the different explants and LD50 doses corresponding to 50% of viability or survival of callus, embryogenic callus, globular and torpedo stage embryos and 50% growth reduction (GR50) of shoot were also determined. Callus explants showed a relatively high radio-resistance (LD30-LD50 50-100 Gy) in comparison with entire plantlets or embryos (LD30-GR50 8-46 Gy). Globular embryo development into plantlets and also leaf area of irradiated plantlets were more severely affected by irradiation than other explants. It was possible to confirm the relative radio-resistance of unicellular explants compared with multicellular explants. Estimation of optimal mutation induction dosage range for various in vitro explants is important for tree crops, especially for coffee improvement.

Formation and Structure of Casein Micelles in Lactating Mammary Tissue

1970 ◽  
Vol 28 ◽  
pp. 150-151
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell
Keyword(s):  
Size Distribution ◽  
G Protein ◽  
Milk Proteins ◽  
Mammary Tissue ◽  
Colloidal System ◽  
Casein Micelles ◽  
The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

Ultrastructural Changes in Tumor Cells During Human Peripheral Blood Monocyte-Mediated Cytotoxicity

1981 ◽  
Vol 39 ◽  
pp. 452-453
Author(s):  
K. E. Muse ◽  
D. G. Fischer ◽  
H. S. Koren
Keyword(s):  
Target Cell ◽  
Human Peripheral Blood ◽  
Mononuclear Phagocytes ◽  
Ultrastructural Changes ◽  
Target Cells ◽  
Limited Information ◽  
Blood Monocytes ◽  
Tumoricidal Activity ◽  
Activated State

Mononuclear phagocytes, a pluripotential cell line, manifest an array of basic extracellular functions. Among these physiological regulatory functions is the expression of spontaneous cytolytic potential against tumor cell targets.The limited observations on human cells, almost exclusively blood monocytes, initially reported limited or a lack of tumoricidal activity in the absence of antibody. More recently, freshly obtained monocytes have been reported to spontaneously impair the biability of tumor target cells in vitro (Harowitz et al., 1979; Montavani et al., 1979; Hammerstrom, 1979). Although the mechanism by which effector cells express cytotoxicity is poorly understood, discrete steps can be distinguished in the process of cell mediated cytotoxicity: recognition and binding of effector to target cells,a lethal-hit stage, and subsequent lysis of the target cell. Other important parameters in monocyte-mediated cytotoxicity include, activated state of the monocyte, effector cell concentrations, and target cell suseptibility. However, limited information is available with regard to the ultrastructural changes accompanying monocyte-mediated cytotoxicity.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

Reverse torque values of abutment screws after dynamic loading: The effects of sealant agents and the taper of conical connections

2020 ◽  
Author(s):  
Arda Ozdiler ◽  
suleyman dayan ◽  
Burc Gencel ◽  
Gulbahar Isık-Ozkol
Keyword(s):  
Dynamic Loading ◽  
Antibacterial Agent ◽  
In Vitro Study ◽  
Control Group ◽  
Silicone Sealant ◽  
Reverse Torque ◽  
The Stability ◽  
Torque Values ◽  
Chlorhexidine Gel

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.

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