Influence of the chemical mutagens on the seed germination, the growth and manifestation of decorative characteristics in the seed offspring of the representatives of the genus Pinus L.

The influence of various concentrations of chemical mutagens on the seed germination, the growth and manifestation of decorative traits in the seed offspring of mountain pine (Pinus mugo Turra), Scots pine (Pinus sylvesrtis L.), and Scots pine “witch’s broom” (“WB”) is assessed. A 0.1 % aqueous solution of colchicine, as well as 0.1, 0.5, and 1.0 % aqueous solutions of dimethyl sulfate (DMS) was used as mutagens. The species-specificity of the influence of chemical mutagens on the seed germination was established. Thus, the treatment of mountain pine seeds with aqueous solutions of colchicine and DMS had some stimulating influence on their germination. On the contrary, the germination of the Scots pine seeds and the seeds collected from the Scots pine “WB” decreased with increasing the DMS concentration in the solution. Among the offspring obtained using chemical mutagens, specimens were identified with changes in the growth strength towards dwarfism, the branching features of which manifested themselves in the form of apical dominance violation and shoot formation growth, with changes in the color of needles, including winter color changes of different-intensity color from green to yellow, bronze or bronze yellow. As a result of the research, 363 specimens with atypical traits were selected for further breeding work.

The effect of chemical mutagens on the characteristics of plants Nigella damascena L. variety Bereginya in M1 generation

We studied the effect of chemical mutagens EMS, NMU and a new mutagen DG-2 on the traits of Nigella damascena L. variety Bereginya in the generation M1. It was found that the treatment of love-in-a-mist seeds with these substances changed such characteristics as plant survival, plant height, and the number of seeds per plant. The greatest influence on these indicators was exerted by nitrosomethylurea. In our study, all chemical mutagens led to a decrease in plant survival and mainly caused plant oppression. In all treatments, a decrease in the total plant height was revealed in comparison with the control. In some cases the number of seeds per plant has decreased. The tested mutagens caused the appearance of morphoses in plants with a frequency of 3.87% to 0.48%, characterized by a change in color and shape of the leaves and the plant dwarfism. The appearance of plants with altered characteristics in the M1 generation assumes hereditary mutations of a different nature in the subsequent generations.

Effects of Hydrogen Peroxide and Benzene Treatments on Morphological Traits of Sesame (Sesamum indicum L.)

A study was carried out on the effects of hydrogen peroxide and benzene treatments on morphological traits of sesame (Sesamum indicum L.) in Keffi. NCRIBEN-02M variety of sesame was exposed to varying concentration (100, 75, 50, 25 and 0%), of benzene, hydrogen peroxide, and the mixture of the two chemical mutagens. The M2 generation of the genotypes were assessed for plant height, number of leaves, leaves area. Benzene treatment, at all levels, have the highest plant height. The increase in number of leaves and leaf area are significant at p≤0.05 and 95% confidence. The optimum concentrations of the mutagens used for mutation in sesame, were effective at 100 and 75% of all the treatments. The most effective mutagen for inducing mutation in sesame under Keffi environment is benzene, followed by Hydrogen Peroxide. Benzene and hydrogen peroxide have proven themselves as chemical mutagens, in mutation breeding. They have unlocked several agronomic traits in sesame. Further, study on these mutagens will enhance the genetic variability in the growing of sesame for higher performance

Methods of Random Mutagenesis of Aspergillus Strain for Increasing Kojic Acid Production

: Kojic acid is an organic acid that is commonly used in the pharmaceutical and cosmetic industries. This acid compound is a secondary metabolite produced by various microorganisms, one of which is Aspergillus oryzae. Typically, improving the strain can enhance kojic acid production. A mutation is one of the tools to perform strain improvement because the change in kojic acid-producing genes effectively increases kojic acid yield. Random mutagenesis is a classic approach for inducing and producing mutants with random mutations. The mutagenesis can be generated by the individual physical and chemical mutagen, combined physical and chemical mutagens, or initiate by protoplast preparation. Aspergillus strains that are exposed to physical mutagens (e.g., UV) or chemical mutagens (e.g., N-methyl-N-nitro-N-nitrosoguanidine (NTG)) showed their abilities in increasing kojic acid production. Several new mutation methods, such as Ion Beam Implantation and Atmospheric and room temperature plasma (ARTP), also showed good responses in enhancing the production of biological products such as kojic acid. This review compared different random mutagenesis methods of Aspergillus strain with various mutagen types to provide better insight for researchers in choosing the most suitable method to increase kojic acid production.

Effect of Some Chemical Mutagens on Nutrient Compositions of Sweetpotato (Ipomoea batatas (L.) Lam)

Effects of sodium azide (SA) and colchicine (COL) (chemical mutagens) on some nutrient compositions of four varieties of sweetpotato (Butter milk, TIS87/0087, UMUSPO/3 and UMUSPO/1) were investigated at the Biotechnology Laboratory of the National Root Crops Research Institute Umudike, Nigeria. The parent plants were treated with sodium azide and colchicine mutagens at concentrations of 0%, 0.03%, 0.05% and 0.07%. Storage roots of the M2V2 generations from the mutant plants were used for the nutrient composition analysis using recommended standard procedures. Nutrient traits studied were: moisture content (%), dry matter content (%), amylose and amylopectin contents (%), starch yield (%), starch content % based on fresh weight and starch content % based on dry weight. Mutants with higher dry matter content than the control were observed in TIS87/0087 treated with SA and COL 0.03%. SA and COL 0.05% produced mutants with higher amylose content (and lower amylopectin) than the control in TIS87/0087. UMUSPO/3 treated with SA 0.03% and SA 0.05% produced mutants with higher values for amylose content (and lower values for amylopectin) than the control; the same variety treated with colchicine (COL 0.05%), recorded higher value for amylose content (and lower value for amylopectin) than the control. These findings showed that sodium azide and colchicine mutagens were potent in inducing variations in nutrient composition of sweetpotato.

EFFECT OF PHYSICAL AND CHEMICAL MUTAGENESIS IN LITTLE MILLET (PANICUM SUMATRENSE ROTH EX ROEMER AND SCHULTZ) ON SEED GERMINATION, SEEDLING SURVIVAL THROUGH INDUCED MUTATION

Little millet (Panicum sumatrense Roth ex Roemer & Schultz) belongs to Poaeceae family and it is Indian in origin. Milletsare mostly rain fed crops and used as food and fodder. Mutations can be induced in a variety of ways, such as by exposure to electromagnetic or ionizing radiation or chemical mutagens. The seed of little millet variety of Co (samai) 4 seeds were treated with different dose/concentration of physical mutagens (5,10,15,20,25,30,35,40,45 and 50KR) and chemical mutagens like EMS (Ethyl Methane Sulphonate) (5,10,15,20,25,30,35,40,45 and 50 mM). After that the treated seeds are sown in Petri dish under the laboratory conditions. It was found that the M1 generation is effected in seed germination, seedling survival and morphology mutation.

Induced mutations in crop plants at Instituto de Genética “Ewald A. Favret”: mutants of scientific and/or agronomic interest

The use of induced mutations techniques in crop plants at Instituto de Genética “Ewald A. Favret” (IGEAF) INTA, started in 1949, with the pioneer work of Ewald Favret, who studied the effects of physical and chemical mutagens on barley (Hordeum vulgare) and wheat (Triticum aestivum). IGEAF contributed with several novel results about the effects of important chemical mutagens such as ethyl methane sulfonate (EMS) and sodium azide, and their interactions with X-rays, on barley and wheat. During several decades, a good deal of the research was directed to study the relationship between the different effects of mutagenic treatments on the M1 and subsequent generations, and its implications for efficient selection of induced mutants. Many original barley and wheat mutants have been isolated at IGEAF, which early on contributed to elucidate the genetic basis of characters like the hormonal control of growth, the grain protein content and diseases reactions. Besides, several other novel mutants were isolated and characterized including genetically unstable mutants, which are able to originate new heritable variability. One of these mutants is the barley chloroplast mutator (cpm) from which some interesting mutants have been isolated. Moreover, a high throughput strategy for the screening of plastome mutants originated by the cpm was developed (cpTILLING) that allowed the detection of 61 different mutational events, showing the cpm as an extraordinary source of plastome mutants. On the other hand, protocols for direct selection of wheat mutants tolerant to drought were developed and promising advanced lines are at present investigated. Furthermore, a mutant allele of the AHAS (acetolactate synthase) gene in wheat conferring imidazolinones herbicides tolerance, was isolated. The incorporation of this allele to other genetic backgrounds showed increased levels of tolerance, which in one family were observed in association with increased Fusarium tolerance. In addition to the work done in barley and wheat, interactions with several breeding programs in other crops were carried out. Finally, some commercial achievements of INTA obtained by using induced mutations techniques are briefly described; being the most important the case of the INTA rice (Oryza sativa) breeding program for developing imidazolinones tolerant commercial varieties that in recent years covered 70% of the irrigated rice area in Latin America.

MUTATION BREEDING FOR CROP IMPROVEMENT: A REVIEW

Despite the fact that the world is at the rapid phase of agricultural modernization, but we are still concerned about food security. To meet the demand of exponential increase in population there is requirement of 70% more food by 2050. To overcome this situation we have to improve our existing crop varieties and make them genetically diverse, adaptive to climate change, input use efficient, high yielding, enhanced nutritional attributes, and better adaptable to a wide range of agro-ecosystems and should not deteriorate existing environment. Among the various methods of breeding to improve crop varieties mutation breeding (induced mutation) plays a crucial role for the development of genetic variation among themselves. Over past five decade mutation breeding is getting more popular and till now 3,362 mutant plant varieties from 240 different plant species in more than 75 countries are released. Different types of physical, chemical and combined mutagens have been used by various breeder to induce genetic variability in various crops. 2635 varieties are developed by physical mutagens, 398 varieties are developed by chemical mutagens and 37 varieties are developed by combination of physical and chemical mutagens. Continent wise, 82 varieties are developed by Africa, 2049 by Asia, 10 by Australia and Pacific, 959 by Europe, 53 by Latin America, and 209 by North America. Similarly, 1602 major cereals, 501 major legumes and 86 major oil seed mutant crop varieties are developed by mutation breeding/induced mutation. Mutation breeding improve several qualitative and quantitative characters of crop plant and is successfully applied in several cereal, grain legume, oil seed, vegetable, fruits, medicinal plant, ornamental plants and fodder crops. With the advancement of various plant breeding, genetics, and biotechnological tools mutation breeding contribute toward the increase in global food and agriculture production which ultimately overcome global hunger and improve the nutritional status of the globe.

Effects of Ethyl methanesulfonate (EMS) on Seedling and Yield Contributing Traits in Basmati Rice

Increasing genetic diversity in crop plants has been used for chemical mutagenesis. Through the application of various mutagenic agents, over 430 new varieties have been derived as rice mutants (Oryza sativa L.) Chemical mutagens such as ethyl methane sulphonate (EMS), diepoxybutane derivative (DEB), sodium azide, and gamma ray, x-ray, and quick neutron irradiation have been commonly used to induce a large number of functional variations in rice and others crops. Among chemical mutagens, ethyl methane sulfonate (EMS) is the alkylating agent most widely used in plants because it induces nucleotide substitutions to be extremely frequent, as detected in various genomes. In this study, seeds of potential genotype of the popular variety, (Oryza sativa L. Super Basmati variety) were treated with EMS at concentrations of 0.25%, 0.50%, 0.75%, 1% and 1.5%. Various measurements on the M1 generation determined EMS sensitivity. As concentration of applied EMS increased, will decrease in germination, shoot length, root length, plant height, productive tillers, Panicle Length, Total Spikelet, sterile spikelet and fertility under field conditions were observed in M1 generation as compared to the non-treatment control. Emergence, shoot length, root length, plant height, productive tillers, Panicle Length, Total Spikelet, sterile spikelet and fertility also decreased with increases in EMS mutagenesis in an approximately linear fashion. The LD50 values were observed based on growth reduction of seedlings after EMS treatment with 0.25% and 0.50% on the rice variety (Oryza sativa L. spp.).