Showing papers on "Mutation breeding published in 2015"

Induced Mutations and Crop Improvement

Abstract: Genetic variation is the mainstay which plant breeders require to produce new and improved cultivars. The opportunity of obtaining novel traits exists through induction of mutations. Induced mutations have played a significant role in meeting challenges related to world food and nutritional security by way of mutant germplasm enhancement and their utilisation for the development of new mutant varieties. A wide range of genetic variability has been induced by physical and chemical mutagens. In the past several decades, induced mutations have contributed immensely to the development of improved varieties in several crop plants. Cellular and molecular biology tools have led to enhanced efficiency of induction, detection and deployment of mutations. Till date, 3,218 mutant varieties have been released worldwide. More than 60 % of officially released mutant varieties are from Asia with China, India and Japan topping the list. The mutant varieties developed and released in major crops have been cultivated by farmers in large areas and have resulted in increased food production, thus contributing to food security. In this chapter, various aspects of mutation induction, applications and examples of successful use of induced mutants in crop improvement programmes are presented.

Conventional Plant Breeding Principles and Techniques

Abstract: Conventional plant breeding is the development or improvement of cultivars using conservative tools for manipulating plant genome within the natural genetic boundaries of the species. Mendel's work in genetics ushered in the scientific age of plant breeding. The number of genes that control the trait of interest is important to breeders. Qualitative traits (controlled by one or a few genes) are easier to breed than quantitative traits (controlled by numerous genes). General steps in breeding are: objectives, creation/assembly of variability, selection, evaluation and cultivar release. Breeders use methods and techniques that are based on the mode of reproduction of the species self-pollinating, cross-pollinating, or clonally propagated. The general strategy is to breed a cultivar whose genetic purity and productivity can be sustained by its natural mating system. There are six basic types of cultivars: pure line, open-pollinated, hybrid, clonal, apomictic and multilines. The common methods for breeding self-pollinated species include mass selection, pure line selection, pedigree, bulk population, single seed descent, backcrossing, multiline and composite. Methods for breeding cross-pollinated species include mass selection, recurrent selection, family selection and synthetics. Hybrid cultivar breeding exploits the phenomenon of heterosis, and is applicable to both self- and cross-pollinated species. Polyploids have complex genetics. Hybridization of parents is often accompanied by infertility of the hybrid. Mutation breeding may be resorted to when the gene of interest is non-existent in nature and may be induced. Also, sometimes, the desired trait is found in wild relatives of the species and may be introgressed into cultivated species through pre-breeding.

Assessment of genetic response and character association for yield and yield components in Lentil (Lens culinaris L.) population developed through chemical mutagenesis

Abstract: Genetic variation is imperative to any plant improvement program Therefore, this study was primarily based on this aspect of inducing desirable genetic variation for enhancement of the available lentil genetic diversity The lentil seeds were treated with methyl methanesulfonate (MMS) alone and in combination with dimethyl sulfoxide (DMSO) for inducing polygenic variation as well as determining the impact of DMSO on mutagenecity of MMS Comparative observations were recorded for bio-physiological damages, morphological variation, and quantitative traits to assess the genetic response of the lentil cultivar L 4076 toward the different concentrations of chemicals Significant statistics suggested that the DMSO interfere with the extent of mutagenecity of MMS in lentil which could be attributed to either synergistic action of both or variation in MMS uptake The outcome of mutagenesis on the character association study revealed that mutagenic treatments can modify significantly the manner of associa

Identification of novel mutants through Electron beam and Gamma irradiation in chickpea (Cicer arietinum L.)

Abstract: Chickpea is an important food legume grown worldwide. There is an increasing concern on narrowing of genetic base in mos t of the gra in legumes including chickpe a. Mutagenesis using ionizing radiations is one of the many ways of increasing genetic variability. To explore the potential of electron beam irradiation for mutagenesis and to compare it to gamma rays, seeds of a popular chickpea variety ‘Vijay ’were irradiated with four doses (200–500 Grey) of either electron beam or gamma rays. The M1 plants were grown in the field, harvested individually, and sown in the subsequent year to raise M2 plant to row progenies. Chlorophyll and other morphological mutants were identified in the M2 generation. The mutation frequency was found to be more for electron beam irradiation as compared to gamma rays treatments of the same dose. The overall mutation frequency calculated as chlorophyll mutants per 1000 M2 plants was almost double in case of electron beam (17.82) as compared to gamma irradiation (8.64). The overall percent of M1 derived families segregating for chlorophyll mutations was 4.42% for gamma rays while it was 9.42% for electron beam. Mutagenic effectiveness and efficiency was also higher for electron beam irradiation as compared to gamma rays of same doses. Some morphological mutants like no serration mutant, missing leaflet mutant, round leaflets with open flower were observed. Other putative mutants with agronomical importance (large pod, more branches, green canopy at harvest, early flowering, early maturity etc) were also isolated. These mutants constitute an important repository and may find uses in basic studies as well as in chickpea improvement program.

Assessment of the effects of gamma radiations on various morphological and agronomic traits of common wheat ( Triticum aestivum L.) var. WH-147

Abstract: The aim of the present study was to assess the effects of different doses of gamma radiations on various morphological and agronomic traits of common wheat in order to identify the most effective radiation dose which can be applied for successful mutagenic research studies. For this purpose, dry and healthy seeds of ‘WH-147’ bread wheat cultivar were exposed to different doses of gamma radiations (5, 10, 15, 20, 25 and 30 kR) at the Bhabha Atomic Research Center (BARC), Mumbai. All the traits studied showed a gradual decrease in their mean values with the increasing intensity of gamma radiations except in 15 kR at which spike number per plant and seed weight showed some increment over the control sets. It has been concluded from the study that higher radiation doses (25 kR and 30 kR) have reduced mean values and increased quantitative variability for most of the traits studied which could be successfully employed in mutation breeding for the improvement of this important cereal crop.

Gamma Radiation Induced Chlorophyll Mutations in Cluster bean (Cyamopsis tetragonoloba (L.) Taub) Var. NCB-12

Abstract: In the present investigation, the frequency and spectrum of chlorophyll mutations was studied in the cluster bean Var. NCB-12 using a physical mutagen gamma rays. The seeds of cluster bean variety NCB-12 were irradiated with 10,20,30,40 and 50 kR doses of gamma rays using 60 CO as a source of radiation at Mutation Breeding Centre, Department of Biotechnology, B.A.R.C. Trombay, Mumbai. The treated seeds were grown immediately in the field along with control following RBD method to raise M1 generation. The M2 population was screened for the frequency and spectrum of chlorophyll mutations. In M2 generation, lethal chlorophyll mutations and viable mutations were screened up for four weeks and through out the plant maturity duration. It was reported that frequency of chlorophyll mutations increased with increasing doses of gamma rays. The highest chlorophyll frequency 4.22% was recorded in 50kR treatment and lowest 1.87% was at 10 kR treatment. The frequency of chlorophyll mutants was higher at higher doses and lower at lower doses of gamma rays and 50 kR dose is found more efficient inducing chlorophyll mutations. The spectrum of chlorophyll mutation showed four types of chlorophyll mutants namely chlorina, xantha, albina and striata. Out of these mutants, chlorina mutant was 5.72%, showed maximum frequency whereas albina mutant 3.06% was least frequent. The spectrum of chlorophyll mutants was found dose dependent in this study.

Studies on induced physical and chemical mutagenesis in groundnut ( Arachis hypogia )

Abstract: Mutation breeding has been widely used for the improvement of plant characters in various crops. It is a powerful and effective tool in the hands of plant breeders. In any mutation breeding program, selection of an effective and efficient mutagen is very essential to produce high frequency of desirable mutation. Groundnut ( Arachis hypogia ) var. VRI-2. was treated with different concentration of physical and chemical mutagen namely gamma rays 10, 20, 30, 40, 50 and 60 KR and Ethyl methane sulphonate (EMS). For inducing mutation various concentration of EMS such as 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 % for six hours were applied to 200 seed sample of each concentration and one respective control. The LD 50 value was observed in 50% of gamma rays and 0.5 % of EMS. The morphological and yield characters were significantly reduced seed germination, seedling survival, days to first flower, plant height, number of leaves per plant, number of grains per plant, grain length and breath, 100 grains weight, grain yield per plant, fresh and dry weight per plant. The increasing doses/concentration of gamma rays and EMS decreased in phenotypic and yield characters in M1generation. The mutagenized populations showed significantly higher variability in the M2 generation. Mutant lines showing higher yield per plant than the respective parents and checks were isolated in M2 and subsequent generation were significantly more pod yield and yield components than the untreated plants.

Amelioration of seed yield, oil content and oil quality through induced mutagenesis in sesame (Sesamum indicum L.)

Abstract: Thirty mutant lines selected from 3 widely adapted genotypes of sesame viz. Rama, SI 1666 and IC 21706 (ten from each of the three genotypes), developed by induced physical (?-rays) and chemical (EMS) mutagens, were evaluated against their respective control genotype for yield and its important attributes in M 4 generation to reveal the ramification of mutagens for disclosing the magnitude of variation among mutants in advance generation and also to identify the promising positive mutants to refurbish new improved varieties of sesame. Mutants professing higher seed yield were evaluated for oil quantity and quality. All selected mutant lines evinced improved seed yield over their respective controls. Irrespective of the genotypes highest yield was recorded in the line induced by 0.5% EMS. Based on mean seed yield and its components, selected 10 superior mutants, also possessed high oil percentage with a better oil profile having relatively more polyunsaturated fatty acid content, specially linoleic acid, than the control, indicating potentiality of mutation breeding to restructure plants with high yield, improved oil percentage and quality. DOI: http://dx.doi.org/10.3329/bjb.v44i1.22718 Bangladesh J. Bot. 44 (1): 15-22, 2015 (March)

Cytogenomics and Mutagenomics in Plant Functional Biology and Breeding

Abstract: One of the most important breakthroughs in the history of genetics and plant breeding was the development of plant cytology and experimental mutagenesis, which later brought about plant cytogenetics and mutation breeding and now they have entered in functional biology era with the unprecedented development of plant molecular cytogenetics, genetics, and functional genomics. Application of cell biology particularly chromosome biology in the fields of plant genome structure and function has ushered the development of plant cytogenomics. Development of advanced technology like DNA base-specific fluorescence banding, GISH, and FISH-based chromosome painting has greatly facilitated the identification, localization, and mapping of chromosome-specific markers in plants, which is of high importance in plant molecular systematics, species identification, detection of hybrid nature, alien chromosomes and chromosomal aberrations, analysis of somaclonal variations, and diversity analysis. The dynamism of chromatin architecture and cell cycle, representing chromosome functional biology, is another important part of plant cytogenomics. On the other hand, mutagenomics is defined as applied mutation breeding, in which genomic information and tools are utilized in the designing of breeding strategies, screening, selection and verification/authentication of natural and induced mutants, and the utilization of desirable mutations in the breeding processes. Considerable progress has been made in recent times in breeding of cereals, legumes, oil seeds, vegetables, horticultural crops, spices and condiments, fiber-yielding plants, and medicinal and aromatic plants for diverse types of desirable agronomic and functional traits including disease and abiotic stress resistance/tolerance; herbicide resistance; lowering of anti-nutritional factors; enhancement of proteins, minerals, vitamins, essential amino acids, flavonoids, antioxidants, and dietary fibers; enrichment of soil nutrition; enhancement of ornamental, medicinal, and aromatic values; and development of functional and therapeutic foods and other diverse traits related to nutritional quality and high yield. This can be found in a mutant population which carries variant forms of potentially each and every gene present in a particular genome. The functionality of mutagenomics is greatly enhanced due to integration of classical mutagenesis with modern “omics” technology through the development of desirable diploid mutants, recombinant inbred lines, and aneuploid and polyploid lines as effective cytogenetic tools, utilizable in genome mapping and analysis. Functional sets of aneuploid tools are now available in different edible plants, through which several morphological, biochemical, and molecular traits/markers have been assigned on definite chromosomes to construct linkage maps. Recently, induced mutations showing alterations in antioxidant defense response have been identified and tested against diverse types of abiotic stresses to reveal intrinsic cellular and metabolic events toward sensitivity of seed plants to salinity, drought, metal toxicity, and other stresses. These mutations are giving vital inputs, which can be used in formulating effective breeding strategies in different agroclimatic conditions. Mutagenized population has revealed altered pattern of genome response and can also be exploited in enhancing production of natural plant products like antioxidants and flavonoids. Furthermore, these large mutant populations have the potential in reverse genetics approach by employing various techniques, particularly “Targeting Induced Local Lesions in Genomics (TILLING)” technology to better understand gene functions through high-throughput mutation screening, and have been successfully used in major crop plants along with model plant Arabidopsis. The development of mutagenomic approach, thus, provides a cost-effective, clean, and easy-to-use functional tool to increase the genetic diversity and in utilization of this diversity in plant molecular mutation breeding through modern genomic methods.

Mutation breeding: a tool to improve wheat yield and yield components

Abstract: The studies were conducted to explore the effect of gamma irradiations on M3 generation of wheat genotypes at Nuclear Institute of Agriculture, Tandojam during 2012-13 rabi season. ANOVA results revealed that treatment means were non-significant for plant height and 1000 grain weight, whereas, significant (5% probability level) for spike length and grain yield. Genotypes mean squares revealed highly significant (1% probability level) effects in all the four traits under study. On an average, Khirman (Mutant) genotype produced highest grain yield per plant (12.9g) as against its normal genotype (untreated) which yielded 11.9 gm yield per plant. It was concluded that when Khirman was treated with 250 Gy gamma rays, it yielded highest (14.2gm) per plant as compared to other gamma irradiation treatments. The information generated through this study will be helpful for the breeders while making selection of the high yielding stable mutant lines with improved traits for future breeding.

Genetic Improvement in West Sumatera Landraces to get The Early Maturing Mutants by Induced Mutations

Abstract: This study aims to improve local rice genetic West Sumatra to acquire properties that are superior (more early maturity) through mutation breeding. This study was conducted from April 2009 to December 2010. In 2009 screening at the stage orientation doses M 1 to obtain a dose treatment is effective in generating genetic diversity is very valuable in the selection effort. In 2010 the selection in a population of M2 to getting properties older than early maturing crops (early maturing mutant). The results showed that the treatment irradiation dose of 200 Gy is the dose that is effective in generating genetic diversity. At these doses have formed extensive genetic diversity for the variable character of the age and height of the plant. With the extent of genetic diversity of the resulting mutant candidates that can be selected at this stage of M 2 . From the selection made at the stage of early maturing mutant M 2 candidates obtained as many as 86 candidates with the mutation frequency of 0.14%, as well as short mutant (dwarf) and a semi-short (semi-dwarf) were 97 mutants with mutant frequency of 0.16%. Candidates mutant is a mutant candidates promoting to have better character as a result to be developed in the future

Breeding High Producers of Enduracidin from Streptomyces fungicidicus by Combination of Various Mutation Treatments

Abstract: Enduracidin is a kind of lipodepsipeptides and composed by a 17 amino acid residual conjugated with a fatty acid strain. It is used as a feed additive approved by EU because of its high safety, low toxicity, low-residue, and activity against a wide variety of Gram-positive bacteria. Here, we combined a physical mutagenesis of 137Cs γ-irradiation with the atmospheric and room temperature plasma (ARTP) biological breeding system to improve enduracidin productivity in the industrial Streptomyces. The mutation rates of spores treated by ARTP for 1 min and by 137Cs γ-irradiation for 500 Gy dosages were 26.51 and 19.41 %, respectively. An optimal process for breeding by the combination was proposed. Through the high throughout screening method, the mutant Streptomyces fungicidicus S-224 was obtained, and its enduracidin yield reached to 1.58 g/L that was 1.65-fold to the original strain. The mutation breeding combined ARTP with 137Cs γ rays was the first trial and provided an alternative method for industrial strains improvement.

Induced Mutations in Plant Breeding

Abstract: Many important traits for plant domestication and improvement have resulted from human selection for novel alleles of structural or regulatory genes. In addition to naturally-occurring genetic mutations, novel alleles have been induced in plants by chemical and physical mutagenesis. The goal of mutagenesis is to induce genetic variation in cells that give rise to plants, while minimizing chimeras, sterility and lethality. For several crop species, chemically-mutagenized populations of a few thousand lines were sufficient for finding the desired phenotype. The efficiency of mutation breeding can be improved by screening plants at the genetic level, prior to phenotypic analysis. High-throughput physical methods and, increasingly, next-generation sequencing are being used to identify lines with induced mutations in candidate genes. An alternative approach to increasing the precision of mutation breeding is through gene-specific mutation using engineered nucleases. Allelic diversity in candidate genes, whether induced naturally or experimentally, can be a resource in breeding programs for developing new agricultural traits.

Physical and chemical mutagenic effect on pollen fertility in M1 generation of Garden Bean [ Lablab purpureus (L.) Sweet var. typicus cv. CO (Gb) 14]

Abstract: Mutation breeding has been widely used to develop a large number of desirable varieties in field and horticultural crops. The present study was performed by exposing the seeds with Gamma rays and Ethyl Methane Sulphonate to assess the pollen fertility in M1 generation. It was observed, that the pollen fertility decreased with increasing dose/ concentrations of mutagens. The results showed that the treatment of EMS was more effective in reducing pollen fertility as compared to gamma rays and control. Pollen fertility percentage was better in control when compared to Gamma rays and EMS. Lower dose/ concentrations of these two mutagens produced less biological damage and would be suitable for inducing desirable attributes in Garden bean.

Clustering common bean mutants based on heterotic groupings

Abstract: Common bean ( Phaseolus vulgaris L. ), is an important legume crop in sub-Saharan Africa (SSA). Most of the local varieties are favoured for their colour and taste, but have a low yield potential of 0.3 to 0.5 metric tonnes per hectare. Mutation breeding is a crop improvement tool in beans that can create new alleles, which when advanced beyond mutated generation 5 (M5), produces stable mutants, which may possess desirable characteristics. These mutants may result in rapid genetic advance and help address issues of low bean productivity. The objective of this study was to cluster bean mutants from a bean mutation breeding programme, based on heterotic groupings. This was achieved by genotyping 16 bean genotypes, using 21 Simple Sequence Repeats (SSR) bean markers. From the results, three different clusters A, B and C, were obtained suggesting great genetic diversity among the bean mutants and these cluster groups (A, B and C) can be taken as heterotic groupings. Depending on the phenotypic trait under consideration, crossing of two distinct genotypes from different cluster groups may lead to hybrid vigour. Furthermore, to create genetic variability for further bean improvement, the breeder can cross distinct genotypes from different cluster groups, which after several generations of selfing accompanied by selection may lead to desirable progenies Key Words : Genetic variation, mutation breeding, Phaseolus vulgaris

Rapid propagation method of willow herb

Abstract: The invention provides a rapid propagation method of willow herb. The rapid propagation method comprises the steps of obtaining of an aseptic explant, induction of calluses, mutation breeding of calluses, differentiation of calluses, rooting induction and the like. The willow herb prepared by the rapid propagation method has the advantages that the mutation frequency can be increased, rich mutants can be obtained and choices can be increased, and therefore, the breeding cycle is shortened and rich materials are provided for breeding new varieties.

Biotechnological Study of Comparative Mutagenicity on Morphological and Phenological Traits in Wild Chickpea

Abstract: The chickpea is one of important leguminous cereal crop and India, largest producer of the crop The major concern of breeding is, therefore to increase the genetic potential for yield. The genetic diversity within the genus and characterization of interspecific relationship are crucial for a better exploitation of the genetic resources available for crop improvement. Mutation induction offers the possibility to induce the desired attribute that cannot be found in nature or have been lost during the evolution The crossability barriers might be eliminated from the wild chickpea species through the mutation breeding making it suitable candidates for introgression towards the improvement programme.. The chemical and physical mutagen showed the potential to cause the mutation in the wild chickpea. The variation was observed between control and its induced mutants. The induced mutants with suitable qualitative and quantitative traits which may be utilized in to the improvement breeding programme.

Rapid propagation method for mutation breeding of herba verbena officinalis

Abstract: The invention discloses a rapid propagation method for mutation breeding of herba verbena officinalis. The method comprises steps of disinfection of seeds, mutation of the seeds, induction of callus tissue, differentiation of callus tissue, rooting induction and the like. According to the method, the soluble protein content of seedlings can be increased through irradiation of ion beams, the protective enzyme system activity is improved, the seed stress resistance is improved, the genetic stability is good, and the regeneration rate of seedlings is high.

Operation method for salvia splendens EMS(Ethyl methane sulfonate) mutation breeding

Abstract: The invention belongs to the field of agriculture, and especially relates to an operation method for salvia splendens EMS(Ethyl methane sulfonate) mutation breeding. A EMS solution with the concentration of 1% is employed for mutagenizing more than 5000 seeds for 6 h, then a corresponding screening method is employed for breeding aiming at different group sizes and selection key points of various generations in the field; mutagenic progeny breeding is mainly performed at M2 generation, flower-color variant breeding must continue to M4 generation, 20 or more seeds are reserved for each variant, 40 or more seeds for a single-plant seed mixture are sowed for forming a next generation, and after breeding for 5-7 generations is performed, a new strain with relatively good stable and consistency and obvious singularity is obtained. According to the method, multiple beneficial variations according to breeding target are obtained though less workload and definite operation. By employing the method, breeding for different generations can be performed according to the breeding target of salvia splendens, and excellent new materials can be obtained.

Some Biochemical and Biotechnological Perspectives in Wild Chickpea and its Induced Mutants

Abstract: The genus Cicer comprises 9 annual species and 31 perennial species and out of 9 annuals one species is under cultivation namely Cicer arietinum The existing genetic variability has been harnessed in plant breeding programme which further narrowed the genetic base in cultigens Therefore, from the variation enhancement point of view, the present study has been undertaken to assess the mutagenicity of the physical and chemical agents The mutation breeding or mutagenesis is one of the important and useful technique and protocol to increase the mutation spectrum in the wild species which in turn could be introduced into the cultivated species to improve the qualitative and quantitative traits SDS- PAGE electrophoresis is significance tool to assess the variation in the treated materials in form of protein profile The seed protein profile has been studied in wild chickpea and its mutant treated with chemical and physical mutagens separately and in combination treatment and compared with the untreated parent The analysis of the banding pattern of the control and induced mutants has been performed as per UPGMA grouping and Jaccard Similarity Coefficient The maximum major band has been observed in the control while its mutants represent less than that of the control The polypeptide bands shows varying size from 592 KDa to11908 KDa The genetic distance between all the 10 treatment varied from 0333 to 075 as revealed by Jaccard Similarity Coefficient The dendrogram represent one parent and 9 mutants into two major cluster in the present investigation The induced mutants represent the deviation from the parent indicating variation when compared to the control in the present study

Breeding method of novel soybean species

Abstract: The invention discloses a breeding method of novel soybean species, and belongs to the technical field of agricultural crop breeding and cultivation In the provided breeding method, wild soybean and cultivated soybean are both subjected to space mutation breeding, then the wild soybean and cultivated soybean are hybridized, and finally a novel soybean species, which has the advantages of strong resistance, high yield, and good quality, is obtained

Physical and Chemical Mutagenesis for Improvement of Chilli ( !"#$%&'(!))&&' L.)

Abstract: A comparison of the effectiveness and efficiency of gamma rays and ethyl methanesulfonate (EMS) for inducing mutation in chilli seeds of 10 different doses along with one respective control. Seeds were treated with 10, 20, 30, 40 and 50 kR of gamma rays and 10, 20, 30, 40 and 50 mM of ethyl methanesulfonate. The M1 generation was produced from these mutagen treated seeds. Several unique and interesting chlorophyll and viable mutants were obtained in the M generation (subsequent generation derived from the seeds of M 2 1 generation). Chlorophyll mutations are used to evaluate the genetic effects of various mutagens. The spectra of chlorophyll mutants albina, chlorina, viridis and lutescens were most frequently. In M generation, gamma 2 rays induced higher proportion of chlorophyll mutants than EMS. Frequency of viable mutants was, in general, higher in treatments with EMS than with gamma rays. Treatment with 30 mM EMS was more effective in inducing desirable mutations at the highest frequency. The desirable viable mutants of long and dark red pods, base non-bulging fruits, flower mutant (normally pentamerous flower but an abnormal behavior of trimerous, tetramerous, heptamerous), two or three flowers on a peduncle, profuse branching and pod setting and genic male sterility were isolated from different treatments. Lethality or biological injury, apparent as reduced germination, increased with increasing dose of gamma rays and EMS. Mutagenic effectiveness and efficiency generally increased with increasing dose of EMS. Mutation breeding will significantly increase the chilli amelioration both the effectiveness and efficacy of induced variability of desirable traits to develop improved genotypes.

Mutation breeding method of flax suspension cells

Abstract: The invention relates to a mutation breeding method of flax suspension cells. The method is characterized in that suspending embryonic single cells and minicell groups are adopted as the mutation objects, the single cells and minicell groups are exposed to ethyl methane sulphonate (EMS), ultraviolet rays, ion beams and a compound variety medicament to be induced to generate variation, cells or cell groups mutated in characteristics are screened out under a set stress environment, then a cell culture technique is adopted for obtaining mutant embryonic cell lines, and by seedling differentiation, the test-tube plantlets are cultivated into flax germplasms with special characteristics by expanding propagation. According to the mutation breeding method of flax suspension cells, provided by the invention, as the suspension cells are mostly originated from single cells, the selective pressure under stress is uniform, highly directed mutant cell lines can be obtained easily, the chimeras can be greatly reduced, therefore the mutation breeding method is an ideal technical method for directly obtaining homogeneous mutants, and has a significant application value in flax breeding.

Cytology ofMorphological Mutants ofVicia fabaL. var.vikrant

Abstract: Mutation breeding is an important tool in bringing genetic variability in plants. Different physical and chemical mutagens are used in mutation breeding to enhance variability. The present experiment was conducted to induce genetic variability in Vicia faba L. var. Vikrant, an autogamous crop, by gamma rays and ethyl methanesulphonate (EMS) used singly or in combinations. Some mutants were identified in M 2 generation which differed morphologically from the control plants. These mutants showed various chromosomal abnormalities. Higher combination treatment plants showed more frequency of meiotic abnormalities than individual doses/concentrations treated plants. Most of the desired mutants viz., bushy mutants, opposite leaves mutant and mutant with four flower s at a node were obtained in lower doses/concentrations of individual treatments whereas the higher combination treatments produced undesired mutants viz., unbranched mutant and one sided branched mutant.