Showing papers on "Mutation breeding published in 2012"

Effect of Gamma Irradiation on Morpho-Agronomic Characteristics of Soybeans (Glycine max L.)

Abstract: Mutation breeding in crop plants is an effective approach in improvement of crop having narrow genetic base such as soybean. The main objective of the present study is to determine the effect of different doses of gamma irradiation on different morpho-agronomic characteristics. Agronomic traits that were analyzed included; grain yield, number of pods/plant, number of seeds/plant and weight of 100 seeds and numbers of days to 50% flowering. Morphometric characterization of the descriptive data included plant height, stem diameter, number of leaves/plant, leaflet length, leaflet width, number of ramifications/plant, and pod length and width at 3 lodge stage. The results of the present study revealed that the two gamma irradiation doses used (0.2 kGy and 0.4 kGy) decreased significantly most of agronomic and morphological traits evaluated in M1 populations. Different effects of 0.2 kGy and 0.4 kGy irradiation were observed in M2 populations with significant increase of grain yields and yield components in all the three soybean varieties. In general, a significant decrease or no changes of morphological traits were observed for the two irradiation doses in M2 populations. The levels of changes varied among varieties. Potential high yielding mutants were identified in progenies of irradiated seeds.

In vitro mutagenesis for improving date palm (Phoenix dactylifera L.)

Abstract: Genetic variability is needed for the improvement of crops, which can be either spontaneous or induced by mutagen treatments. The frequency rate of spontaneous mutations is very low and can't be used for plant breeding in developing new cultivars. Mutation breeding has been quite successful for producing new mutant cultivars with desirable traits in both seed and vegetative propagated crops (http://www-mvd.iaea.org). Somatic embryogenic cell cultures of date palm were irradiated with gamma radiation, and regenerated plants were transferred in the greenhouse and treated with Bayoud toxin, isolated from the causal fungus Fusarium oxysporum f. sp. albedinis. Several selected putative mutants tolerant to Bayoud disease were initially maintained in the greenhouse and finally transferred in the field for further evaluation. These plants have maintained tolerance to Bayoud disease under field conditions.

Development of an efficient mutagenesis technique using ion beams: Toward more controlled mutation breeding

Abstract: Ion beams have been used as a mutagen to improve the eciency of plant mutation breeding. Mutation b reeding is sometimes perceived as a random process. In this review, we describe our recent progress in developing a more ecient mutagenesis technique using ion beam irradiation combined with sucrose pretreatment or subsequent re- irradiation. To shorten the time required for breeding new cultivars of cyclamen, we identied anthocyanin biosynthesis g enes and examined the eectiveness of PCR screening of irradiated deletion-mutant candidates at early growth stages. We believe this research is a step toward more ecient and controlled mutation breeding using ion beams.

Success story of induced mutagenesis for development of new ornamental varieties.

Abstract: Induced mutagenesis is well recognized as one of the most important technology for the development of new varieties through genetic manipulations. Mutation techniques, using physical and chemical mutagens, have successfully produced quite a large number of new promising varieties in different ornamental plants. This technique has been most successful in ornamental plants due to some additional advantages. Changes in any phenotypic characteristics like colour, shape or size of flower and chlorophyll variegation in leaves can be easily detected. Heterozygous nature of many of the cultivars offers high mutation frequency. The main advantage of mutation induction in vegetative propagated crops is the ability to change one or a few characters of an otherwise outstanding cultivar without altering the remaining and often unique part of the genotype. Voluminous literature for successful application of classical induced mutagenesis have been generated on radio-sensitivity, selection of materials, methods of exposure to gamma rays, suitable dose, detection of mutations, mutation frequency and spectrum, isolation of mutants and commercial exploitation of mutants. Different treatment methodology like recurrent irradiation, combined treatment, split dose, colchicine treatment, ion beam technology, space breeding, TILLING, EMAIL, etc., have been precisely determined for successful development of new varieties. The main bottlenecks in mutation breeding of vegetatively propagated plant are formation of chimeras. Therefore, attempts were made to find out the ways to overcome this situation. Management of chimera and in vitro technique have opened a new way for isolating new flower colour/shape ornamental cultivars through retrieval of mutated cells. Step wise advancement/refinement of practical approaches for application of classical induced mutagenesis and recent techniques for improvement of ornamental crops have been highlighted.

Analysis of drought-tolerant sugar beet (Beta vulgaris L.) mutants induced with gamma radiation using SDS-PAGE and ISSR markers

Abstract: Drought is one of the major environmental stresses which greatly affect the plant growth and productivity. In the present study, various doses (0-75Gy) of gamma rays were applied to investigate the effect of radiation on shoot tip explants. It was observed that the regeneration rates and plant fresh weights decreased significantly with an increase in radiation dose. The optimal irradiation doses for mutation induction were determined at 15 and 20Gy. Afterwards, the induction of somatic mutation in sugar beet (Beta vulgaris L.) was investigated by irradiation of shoot tips with 15 and 20Gy gamma rays. Irradiated shoot tips were sub-cultured and M(1)V(1)-M(1)V(3) generations were obtained. Mutants tolerant to drought stress were selected on MS medium, supplemented with 10 and 20gl(-1) PEG6000. Of the M(1)V(3) plantlets, drought-tolerant mutants were selected. Leaf soluble proteins obtained from the control and drought-tolerant mutants were analyzed by SDS-PAGE. A total of 22 protein bands were determined and 2 of them were observed to be drought-tolerant mutants except the control. Polymorphism was also detected among the control and drought-tolerant mutants by DNA fingerprinting using ISSR markers. A total of 106 PCR fragments were amplified with 19 ISSR primers and 91 of them were polymorphic. The dendrograms were separated into two main clusters. First cluster included M8 mutant plant, which was applied 20Gy gamma radiation and regenerated on selective culture media containing 10gl(-1) PEG6000 concentration, and the second cluster was further divided into five sub-clusters.

Targeted mutation breeding of horticultural plants

Abstract: Mutation breeding can be enhanced by genetic selection for novel alleles. Through targeted mutation breeding, genotypes with induced or natural mutations in candidate genes are identified for cultivar development. For most horticultural plants, targeted mutation breeding may be a more economically feasible approach to trait development than through transgenic technology. Substantial progress has been made in applying targeted mutation breeding to horticulture and this review summarizes recently published work in this area. To date, at least 16 horticultural crops have been screened for natural or induced allelic diversity in over 100 candidate genes. This approach has resulted in traits of commercial use, such as longer shelf-life (tomato, melon), improved starch quality (potato), and virus-resistance (peppers, tomato). Advances in genome sequencing and genetic screening will facilitate the development of cultivars with value-added traits derived from candidate gene polymorphisms.

Radio-Sensitivity of Some Groundnut (Arachis hypogaea L.) Genotypes to Gamma Irradiation: Indices for Use as Improvement

Abstract: Mutation breeding in crop plants is an effective approach in improvement of crop having narrow genetic base such as groundnuts (Arachis hypogaea L.). Determination of effective irradiation dose is prerequisite for mutation breeding and development of genetic variability by induced mutation. Three groundnuts (Arachis hypogaea L.) genotypes (JL12, JL24 and Kimpese) were irradiated to the absorbed doses of 100, 200, 400 and 600 Gy for effective dose determination and to compare their sensitivity to different doses of gamma irradiation in a completely random design. It was found that, irradiation reduced significantly germination and survival percentages of seedlings in higher doses and this reduction was more pronounced in JL 24 cultivar. This sensitivity expresses himself distinctly to the rank of stem lengths and roots. Results show a

Lethal and mutagenic effects of ion beams and γ-rays in Aspergillus oryzae.

Abstract: Aspergillus oryzae is a fungus that is used widely in traditional Japanese fermentation industries. In this study, the lethal and mutagenic effects of different linear energy transfer (LET) radiation in freeze-dried conidia of A. oryzae were investigated. The lethal effect, which was evaluated by a 90% lethal dose, was dependent on the LET value of the ionizing radiation. The most lethal ionizing radiation among that tested was (12)C(5+) ion beams with an LET of 121keV/μm. The (12)C(5+) ion beams had a 3.6-times higher lethal effect than low-LET (0.2keV/μm) γ-rays. The mutagenic effect was evaluated by the frequency of selenate resistant mutants. (12)C(6+) ion beams with an LET of 86keV/μm were the most effective in inducing selenate resistance. The mutant frequency following exposure to (12)C(6+) ion beams increased with an increase in dose and reached 3.47×10(-3) at 700Gy. In the dose range from 0 to 700Gy, (12)C(5+) ion beams were the second most effective in inducing selenate resistance, the mutant frequency of which reached a maximum peak (1.67×10(-3)) at 400Gy. To elucidate the characteristics of mutation induced by ionizing radiation, mutations in the sulphate permease gene (sB) and ATP sulfurylase gene (sC) loci, the loss of function of which results in a selenate resistant phenotype, were compared between (12)C(5+) ion beams and γ-rays. We detected all types of transversions and transitions. For frameshifts, the frequency of a +1 frameshift was the highest in all cases. Although the incidence of deletions >2bp was generally low, deletions >20bp were characteristic for (12)C(5+) ion beams. γ-rays had a tendency to generate mutants carrying a multitude of mutations in the same locus. Both forms of radiation also induced genome-wide large-scale mutations including chromosome rearrangements and large deletions. These results provide new basic insights into the mutation breeding of A. oryzae using ionizing radiation.

In Vitro Mutagenesis and Genetic Improvement

Abstract: In vitro mutagenesis is an important technique which can induce stress tolerance and improve the yield and quality of crop plants. This chapter is an effort to review and compare the useful information obtained through in vitro mutation techniques, including somaclonal variation with the current achievements and future prospects. Plant improvement based on mutations can change one or more specific traits of a cultivar, which can enhance the quality and quantity of crops. Conventional induced mutations have well-defined limitations, especially in crop-breeding applications but the use of in vitro techniques with the conjunction of conventional mutagenesis has overcome this barrier. Tissue culture techniques offer opportunity for variation induction, handling of large populations, use of ready selection methods, and rapid cloning of selected variants which can increase the efficiency of mutagenic treatments. Molecular techniques can provide a better understanding about the potential and limitations of mutation breeding. It is apparent that the relatively high number of research reports compared with the low number of cultivars released suggests that mutagenesis, in combination with tissue culture techniques, needs further coordinated and integrated investigation for the improvement of existing plants. However, in vitro mutation induction has high potential to enhance the crop yields that can be used for the improvement of life style of the mankind. Various stresses cause significant yield losses in crops and significantly affect their productivity; therefore, such techniques can contribute to resolve or reduce some of these constraints. Understanding the mechanism that regulates the expression of stress-related genes is a fundamental issue in plant biology and is utmost necessary for the genetic improvement of plants.

Ethyle methane sulphonate (EMS) induced mutagenic attempts to create genetic variability in Basmati rice

Abstract: Chemical mutagens have long been used to create genetic variability in crop plants for breeding research and genetic studies. In rice, more than 500 varieties have been released through induced mutations. Ethyl methane sulphonate (EMS) is the most commonly used chemical mutagen in plants. EMS normally induces Gas chromatography GC to AT transitions in the genome and thus resulting protein in the mutant plant has different functions than normal. The present study was carried out to investigate the mutagenic effects of different concentrations of EMS on germination and yield parameters of two basmati rice cultivars (Super basmati and Basmati 370). The seeds were subjected to different treatment levels of EMS. The treated and untreated plants were observed under different agronomic parameters. EMS was quite effective in inducing genetic variability in Basmati rice. The results revealed significant difference among all the traits studied. The efficiency of EMS was found to depend upon its concentration and it was higher at lower concentration in both genotypes. The study further revealed that the use of EMS is an effective approach for creating new rice germplasm. Key words: Rice (Oryza sativa L.), induced mutations, mutation breeding, EMS

Rapid generation of rice mutants via the dominant negative suppression of the mismatch repair protein OsPMS1

Abstract: Mismatch repair (MMR) is a conservative pathway for maintaining the genome integrity of different organisms. Although suppression of MMR has resulted in various mutation phenotypes in Arabidopsis, the use of this strategy for mutation breeding in major crops has not been reported. Here, we overexpressed a truncated version of the OsPMS1 protein in rice; this approach is expected to suppress the rice MMR system through a dominant negative mechanism. We observed a wide spectrum of mutation phenotypes in the progeny of the transgenic plants during seed germination and the plant growth stages. Genomic variations were detected with inter-simple sequence repeat (ISSR), and sequencing of the differential ISSR bands revealed that the mutation occurred as a point mutation or as microsatellite instability at high frequencies. Plant lines with agronomically important traits, such as salt and drought tolerance, various tiller number, and early flowering, were obtained. Furthermore, we obtained mutants with important traits that are free of the transgene. Together, these results demonstrate that MMR suppression can be used as an efficient strategy for mutation breeding in rice.

Assessing the mutagenic effects of gamma irradiation on Cajanus cajan (L.) Huth and Vigna unguiculata (L.) Walp landraces using morphological markers

Abstract: Giving the high adaptability, heritability, genetic variability and nutritive values reported in the indigenous landraces of legumes, combined efforts should be geared towards their improvement. The present study aimed at evaluating the sensitivity of “Fiofio” Cajanus cajan (L.) Huth and “Olaudi” Vigna unguiculata (L.) Walp to gamma irradiation using morphological markers. Seeds of these legumes were exposed to gamma irradiation at 0, 200, 400, 600, 800 Gy from 60 Co source. There was significant effect of gamma irradiation on days to 50% seedling emergence in a dosedependent fashion for “Fiofio” but it did not significantly affect the seedling emergence of “Olaudi”. Germination percentage was not affected concerning the two crops but the survival percentage was significantly reduced as the dose of exposure increased, especially for “Fiofio” variety. Growth and yield traits were increased in plants raised from seeds exposed to 200 Gy of gamma irradiation for both legumes. “Fiofio” plants raised from seeds treated with 400, 600 and 800 Gyhave died after two months, while those of “Olaudi” have presented a retarded growth. Explicitly, exposing the seeds of these legumes to 200 Gy of gamma irradiation could serve as a good springboard for their improvement.

Improvement of qualitative and quantitative traits in soybean (Glycine Max (L.) Merrill) through gamma irradiation

Abstract: Gamma irradiation was used at different doses (80, 160 and 240 Gy) on Glycine Max (L.) Merrill cv. Hill homogenous seeds. A single suitable M2 plant was selected and evaluated at M3 and M4 along with its parent and three other varieties as control in RCBD experiment in Sari Agricultural Sciences and Natural Resources University’s experimental field. M-80-709 and M-160-3429 mutant lines were significantly shorter (55.05 and 72.04 cm respectively). Their branch numbers were however significantly more (8.70 and 11.53 respectively) compared to the parent cultivar (80.82 cm and 6.10 respectively) and other genotypes (p≤0.05), when calculated on per plant basis. Besides, the M-160-3429 was characterized by highest grain yield and oil content (38.25 g and 19.22% respectively), in compare with its parent (12.73 g and 19.09% respectively) and all others control cultivars (p≤0.05). The M-160-3429 mutant line with high grain yield and oil content accompanied with some other favorite morphological traits can be considered as a new promising line of soybean for future studies. Results from this study suggested that mutation breeding procedures at the ranges of 80 to 160 Gy is a capable method for breeding higher grain yield including increasing the oil content as well.

Mutation Breeding and Mutagenic Effect of Air Plasma on Penicillium chrysogenum

Abstract: Low temperature air plasma was used as the mutation tool for penicillin-producing strain Penicillium chrysogenum. The discharge conditions were RF power of 360 W, temperature of 40°C in a sealed chamber, and pressure of 10 Pa to 30 Pa. The result showed that the kinetics of the survival rate followed a typical saddle-shaped curve. Based on a statistic analysis, at the treating duration of 10 min, the positive mutation rate was as high as 37.5% while the negative mutation rate was low. The colonial morphology changed obviously when the plasma treating duration reached or exceeded 45 min. After both primary and secondary screening, a mutant designated as aPc051310 with high productivity of penicillin was obtained, and a strong mutagenic effect on P. chrysogenum was observed in the process. It was proved that after five generations, the mutant aPc051310 still exhibits a high productivity. All the results prove that the plasma mutation method could be developed as a convenient and effective tool to breed high-yield strains in the fermentation industry, while expanding the plasm application at the same time.

Cobalt-60 radiation mutation breeding method for rice

Abstract: The invention discloses a cobalt-60 radiation mutation breeding method for rice, which is a technology for deepening prominent breeding of a particular trait through multiple times of radiation. The cobalt-60 radiation mutation breeding method for the rice comprises the following steps: selecting a parent, determining a radiation dose, radiating, planting a conventional single plant, selecting seeds, re-radiating, re-planting, re-selecting and the like. By radiating the specific trait for multiple times and selecting the seeds for multiple times pertinently, a variety with the prominent specific trait is ultimately selected and used in the production, so that the breeding time can be greatly shortened; compared with the ordinary radiation mutation breeding method, the cobalt-60 radiation mutation breeding method for the rice has the remarkable advantages that: plants with limited economic traits and opposite biological characteristics are crossed, so that the specific traits are more prominent; the genetic heterogeneity is improved; and the productivity is improved.

Efficient modification of floral traits by heavy-ion beam irradiation on transgenic Torenia.

Abstract: While heavy-ion beam irradiation is becoming popular technology for mutation breeding in Japan, the combination with genetic manipulation makes it more convenient to create greater variation in plant phenotypes. We have succeeded in producing over 200 varieties of transgenic torenia (Torenia fournieri Lind.) from over 2,400 regenerated plants by this procedure in only 2 years. Mutant phenotypes were observed mainly in flowers and showed wide variation in colour and shape. Higher mutation rates in the transgenics compared to those in wild type indicate the synergistic effect of genetic manipulation and heavy-ion beam irradiation, which might be advantageous to create greater variation in floral traits.

Induced Mutations for Improved Lycopene, Total Antioxidant Properties and Other Quality Factors in Wild Tomato (Solanum pimpinellifoliumL)

Abstract: The objective of the study was to determine biochemical changes in (5) gamma radiation induced variant lines of wild tomato after mutation induction. Five gamma radiation-induced variant lines of wild tomato (Solanum pimpinellifolium L.), selected in the M 3 generation following mutagenic treatment of seeds using three doses (150, 300 and 450 Gy, respectively) of gamma radiation from a Co-60 gamma source, were analysed for their lycopene content, total antioxidant properties, total and soluble solids as well as pH. Fruits of variant line BV-21 (deep red fruits) recorded higher lycopene contents of 146.1 mg/kg on fresh weight basis and 156.7 mg/kg on dry weight basis compared to 136 and 152 mg/kg, respectively for the control. They also recorded higher total antioxidant properties compared to the control. Fruits of variant line BV-40 (yellow fruits) recorded higher total solids of 17.9% and the lowest pH value of 4.17 compared to 12.8% and 4.36 for fruits from un- irradiated plants. The highest amounts of total soluble solids (7%) were contained in fruits harvested from variant lines BV-27 (light red fruits) and BV-23 (deep red fruits) as against 5.6% for fruits from control plants. The study indicates that wild tomato has immense nutritional properties which can be further improved through mutation breeding.

Ultraviolet mutation breeding and acclimatization method of salt-resisting domestic fungus

Abstract: The invention discloses an ultraviolet mutation breeding and acclimatization method of a salt-resisting domestic fungus. According to the invention, initial domestic fungus strains are activated and are subject to mycelium ultraviolet mutation; salt-resisting stains are subject to primary screening, acclimatization and secondary screening by using salt-containing selective culture media, such that the salt-resisting stain is obtained. The method is suitable to be used in salt-resisting stain breeding and acclimatization of domestic fungus varieties such as cap fungus, shiitake fungus and Jew's ear. The method is advantaged in that: the high-salt-resisting mutation strain is obtained with the mycelium ultraviolet mutation and acclimatization method, such that a novel approach of salt-resisting cap fungus breeding is developed. The operation processes are simple, a small amount of equipment is required, the cost is low, such that the domestic fungus breeding method is easy to popularize. A mutation period is short, a forward mutation rate is improved, and an effect is substantial. The obtained strain has a salt-resisting capacity of 2%, stable hereditary characters, and excellent agronomic characters. When the method is used in the productions in saline alkali lands, the quality of cap fungus fruiting bodies is improved; and a fresh-to-dry weight ratio and a storing tolerance are improved by more than 50%. Therefore, the quality of cap fungus is effectively improved, the production cost is reduced, and the economic benefits are substantially improved.

Chemical mutation breeding method for bougainvillea

Abstract: The invention discloses a chemical mutation breeding method for bougainvillea, and relates to the field of the vegetative propagation and chemical mutation breeding of xylophyta and vines The method treats cottage pieces of bougainvillea with sodium azide (NaN3), adopts continuous cottage propagation to create a time and a space which are good for growth of leaf color mutants, and obtains new lines with stable heredity and ornamental value through generation selection, thereby achieving the purpose of chemical mutation breeding By adopting the technical scheme in the invention, large quantities of female parent materials can be treated in one step; the base number of variants is relatively increases greatly; the mutation frequency is increased; the treatment cost is relatively low; and the breeding period can be shorten effectively By utilizing the continuous cottage propagation manner, the growth of leaf color mutants is ensured to be competitive, which is helpful for overcoming the chimera formation, thereby obtaining stable and uniform variants The chemical mutation breeding method can obtain high-frequency mutation and a wide spectrum of variation, and is helpful for the variety improvement of bougainvillea

Induced chemical and physical mutagenic studies in M1 generation of French bean (Phaseolus vulgaris L.)

Abstract: The seeds of French bean varieties Varun and Waghya were treated with chemical mutagens EMS and SA and physical mutagen gamma rays. M1 generation was raised and studied with respect to different morphological parameters such as germination percentage, seedling height, leaf morphological changes, chlorophyll chimeras, pollen sterility and plant survival percentage at maturity. An increasing trend with an increase in mutagenic concentrations/doses could be recorded for leaf morphological changes, chlorophyll chimeras and pollen sterility while germination percentage, seedling height and plant survival percentage at maturity revealed decreasing trend with increasing mutagenic concentrations/doses.

Method for improving mutation breeding efficiency of jatropha curcas plants

Abstract: The invention discloses a method for improving the mutation breeding efficiency of jatropha curcas plants. The method comprises the following steps: selecting seeds of jatropha curcas which are mature in the same year and have the thousand seed weight being more than 700g as mutagenesis seeds; mutagenizing the seeds by the rapid mutagenesis method under the conditions that methanesulfonic acid ethylester with the concentration percentage of 0.5% is used as a mutagenic agent for processing for 4-24 hours; and screening mutated plants after seedling is grown, nursery stock is planted and breeding is performed in the field according to the conventional techniques. According to the invention, EMS (ethylmethane sulphonate) is initially applied in mutagenizing of the seeds of the jatropha curcase, and the optimal usage amount of the EMS is determined by tests; the seeds of jatropha curcase are processed, the mutation rate (the number of the mutated plants/the number of survival plants) of the plants is obviously improved and can reach more than 10%, and mutagenesis cost is greatly reduced; and the method is simple to operate, has good practicability and is not restricted by time and place, thereby providing abundant mutagenesis materials for selecting beneficial mutants with higher oil content in kernel and higher yield of seeds in subsequent breeding.