Improving French bean yield potential through induced mutagenesis using EMS and SA

Horse gram (Macrotyloma uniflorum (Lam.) Verdc.), a drought tolerant pulse and fodder crop, thrives in temperatures between 20 to 30°C. It is crucial for climate resilient agriculture and has potential as a future food source. However, the genetic improvement of horse gram has been significantly constrained, primarily due to its narrow genetic base, which is a consequence of its self pollinating nature. To address this, mutation breeding using chemical mutagens can be an effective method to create new and improved varieties. This study assessed the effectiveness of two chemical mutagens, Ethyl Methane Sulphonate (EMS) and Sodium Azide (SA) on the GPM-6 horse gram variety. Viable mutant frequencies in the M2 generation were evaluated across various concentrations of EMS (0.1%, 0.2%, 0.3%, 0.4%) and SA (0.03%, 0.05%, 0.07%, 0.1%). Mutagenic effectiveness varied between EMS and SA treatments and across concentrations, with no discernible trend in the induction of viable mutants. Higher effectiveness was observed at SA (0.07%) with value of 2.71 followed by EMS (0.1%) at 1.42. SA treatments demonstrated the highest average mutagenic effectiveness (1.21), outperforming EMS (0.64). The results suggest that SA is more effective than EMS in producing viable mutants with desirable traits and fewer deleterious effects leading to healthier and more viable plants

The effect of caffeine (CAF) (a replicative DNA synthesis inhibitor) given as pre-, inter- and post-treatments on the ethyl methanesulfonate (EMS)-induced adaptive response in in vivo mouse bone marrow cells was studied in order to understand the influence of CAF on the adaptive response. The pre-treatment was given 4 h before a combined treatment with EMS (conditioning + challenge) and in another set CAF was given as a conditioning dose and 4 h later the cells were challenged with a high dose of EMS. In the inter-treatment, CAF (40 mg/kg body wt) was administered 2 or 4 h after the conditioning dose of EMS and 6 or 4 h later the cells were challenged with a high dose of EMS. Similarly, in the post-treatment experiments, CAF was injected 6, 12 or 18 h after a combined treatment with EMS. The results revealed that the pre-, inter- and post-treatments with CAF significantly reduced the frequency of chromosomal aberrations compared with the challenge and combined treatments with EMS. It is interesting to note that CAF pre-treatment resulted in a much greater reduction in chromosomal aberrations compared with the inter- and post-treatments. Thus, this is an example of cross-adaptation induced by CAF in EMS-treated in vivo mouse bone marrow cells and the results also demonstrate an influence of CAF on the adaptive response.

Background: Foxtail millet (Setaria italica L.) is a valuable cereal crop with potential for yield enhancement through induced mutagenesis. Creating genetic variability is a crucial step in crop improvement and chemical mutagens like ethyl methane sulphonate (EMS) have proven effective in generating useful mutations. This study was designed to explore the extent of genetic variability induced in the M2 generation of foxtail millet using EMS, with a particular focus on key agronomic traits that influence yield and adaptability. Methods: The experiment was conducted using a randomized block design with EMS treatments at concentrations ranging from 0.2% to 0.9%. The M‚ population was evaluated for agronomic traits including days to 50% flowering, days to maturity, plant height, number of productive tillers, flag leaf length and breadth, panicle length and 1000-grain weight. Data collected were analyzed for heritability and genetic advance to assess the effectiveness of each EMS treatment in inducing useful variability. Results: Among the EMS treatments, T5 exhibited the most promising results, showing superior performance in plant height, number of tillers, flag leaf length, panicle length and 1000-grain weight. This treatment also demonstrated the highest heritability and genetic advance, indicating strong genetic control over these traits and the potential for effective selection. T6 was more influential in altering flowering traits. The results confirm that EMS is an effective mutagen for creating desirable variability, providing a valuable genetic base for breeding programs aimed at improving the yield and adaptability of foxtail millet.

This study was carried out to determine the "Effective Dose of Mutation” (EMD50) for mutation breeding study on Çermik, Kandil and Üçburun pepper varieties grown intensively in Diyarbakır. For this purpose, pepper seeds were exposed to chemical mutagen source Ethyl Methane Sulfonate (EMS) at doses of 0%, 01%, 0.2%, 0.3%, 0.4%, 0.5%, 0.75% and 1% and to irradiation with physical mutagen source Co60 at doses of 0, 50, 100, 200, 300, 400, 500 and 600 Gy. In irradiated and chemically exposed seeds, on the 45th day following seed sowing date, germination percentage (%) for each dose was calculated and seedlings’ lengths were measured to investigate the effects of different doses and EMD50 value was calculated. According to the data obtained as a result of the study; it was found that the germination rate in pepper seeds of all three varieties-genotypes gradually decreased with the increases of doses in application of EMS on pepper seeds. While the decreases were especially evident in the seeds of Kandil and Üçburun varieties subjected to 0.3% EMS dose and 9 hours of application; in Çermik genotype the germination rate started to decrease with 0.5% EMS dose due to local population. It was also found that germinations decreased in all three varieties depending the application of 300 Gy CO60. In 6-hour EMS application, EMD50 values were respectively determined as 0.67%, 0.97% and 1.08%. for Kandil, Üçburun and Çermik. And for 9-hour EMS application, EMD50 values were determined as; 0.52%, 0.77%, 0.89%. Kandil, Üçburun and Çermik varieties. According to the results obtained in the study, the usage of both physical and chemical mutagens in pepper varieties; increasing of doses and durations of mutagens, decreased germination rates and also caused to decrease the plant heights. As a result, it seems possible to obtain variations in peppers with the usage of physical and chemical mutagens to get new varieties in plant breeding.

Capparis spinosa L. flower buds (CS) aqueous extracts are used in Turkey traditional medicine for their diuretic, antihypertensive, poultice, tonic and other properties. The present study evaluates the genotoxic and antimutagenic effects of capers (C. spinosa L.) flower buds aqueous extract on the Allium cepa L root tip meristem cells. The experiment was carried out in three applications: (1) the onion bulbs were treated with 3.10–2 M Ethyl Methane sulfonate (EMS) for 2 h, after than the EMS treatment, the onion bulbs were treated with three different concentrations (10g/L, 20g/L and 30g/L) of aqueous extract from flowering buds for 24 h. (2) onion bulbs were treated with three different concentrations (10g/L, 20g/L and 30g/L) of aqueous extract for 24 h and then with 3.10–2 M EMS for 2 h (3) Onion bulbs were treated with three different concentrations (10g/L, 20g/L and 30g/L) of aqueous extract for 24 h without EMS treatment. 3.10–2 M EMS was used as positive control and tap water (pH 7.3) was u...

Induced mutation in plant improvement has been proven to be one of the alternative ways to generate new sources of genetic variation in blackgram. In this study, dry seeds of VBN 4 blackgram were treated with combination treatment of both gamma rays (400, 500 and 600 Gy) and ethyl methane sulphonate (EMS) (50, 60 and 70 mM) to study the polygenic characters in M2 generation. The mean values for plant height, number of primary branches, number of clusters per plant, number of pods per plant, number of seeds per pod and single plant yield decreased below the control in most of the treatments. The mean single plant yield was more than for the control at 400 Gy+60 mM and 600 Gy+50 mM. Moderate and high phenotypic coefficients of variation (PCV) and genotypic coefficients of variation (GCV) were recorded in yield component characters such as plant height, number of primary branches, number of clusters per plant and number of pods per plant. A high amount of heritability and GA as per cent of mean was noted for plant height, number of clusters per plant, number of primary branches per plant, number of pods per plant, pod length, number of seeds, 100 seed weight and single plant yield. This denoted that these characters are governed largely by additive gene effect, which may be favorably exploited for improvement through simple selection in M2 generation.   Key words: Gamma rays, ethyl methane sulphonate (EMS), blackgram, polygenic variability, M2 generation.&nbsp

The frequency of ethyl methanesulfonate (EMS)-induced mutations to 6-thioguanine resistance in a Chinese hamster ovary cells clone K1-BH4 was studied at many EMS doses including the minimally lethal range (0-100 microng/ml) as well as the exponential killing portion (100-800 microng/ml) of the survival curve. The mutation frequency increases approximately in proportion with increasing EMS concentration at a fixed treatment time. The pooled data for the observed mutation frequency, f(X), as a function of EMS dose X, is adequately described by a linear function f(X)=10(-6)(8.73+3.45 X), where 0 less than or equal to X less than or equal to 800 microng/ml. One interpretation of the linear dose-response is that, as a result of EMS treatment, ethylation of cellular constituents occurs, which is directly responsible for the mutation. Biochemical analyses demonstrate that most of the randomly isolated 6-thioguanine-resistant variants possess a highly reduced or undetectable level of HGPRT activity suggesting that the EMS-induced mutations to 6-thioguanine resistance affect primarily, if not exclusively, the HGPRT locus.

Mutagenesis is a valuable technique for enhancing genetic diversity and improving crop traits. This study investigated the effects of ethyl methane sulphonate (EMS)-induced mutagenesis on the nutritional quality of Bambara groundnut, an underutilised legume known for its high nutritional value, drought-tolerance and adaptability to poor soils. EMS treatments at concentrations of 0.00%, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% were applied to assess their influence on proximate and mineral composition in the M2 generation. Results showed that EMS treatments significantly improved nutritional composition. Crude protein content peaked at 20.20% with 0.3% EMS. The highest potassium (21.73 mg/kg) and phosphorus (61.47 mg/kg) levels were observed at 0.5% EMS. Calcium content was highest at 0.3% EMS (50.84 mg/kg), while sodium (20.89 mg/kg) and manganese (1.88 mg/kg) peaked at 0.4% EMS. Iron content reached its maximum (0.25 mg/kg) at 0.5% EMS. These enhancements in nutrient levels indicate that EMS-induced mutagenesis positively affects the accumulation of both macro- and micronutrients in Bambara groundnut. The study has shown that EMS mutagenesis is an effective approach for improving the nutritional profile of Bambara groundnut, reinforcing its potential role in addressing food security and promoting sustainable agriculture, especially in marginal environments.

Influence of experimental conditions and DNA repair ability on EMS-induced mutagenesis and DNA binding in Escherichia coli K12 : Comparison with mammalian cell mutagenesis

Ethyl methanesulfonate (EMS) is a stable and effective chemical mutagen. Bitter Gourd (Meghna-2) seeds were treated by 0.3, 0.5, and 1% EMS for 24 h and 48 h to optimize EMS mutagenesis. Median lethal dose of EMS was obtained at 0.3% EMS treated for 48 h. After treated by 0.3% EMS for 48 h, 250 M1 plants were grown in field for phenotype determination. In comparison to the control, a decline in germination, leaf shape, fruit size, fruit shape, vine length, and emergence was seen in the M1 generation when the concentration of applied EMS was increased. The fertility of M1 bitter gourd was very low and only 24 lines produced seeds after self crossing. Of the mutant 24 lines in the plant growth, five were dwarf, two were tall, four had retarded fruit size, and 13 had abnormal branching and flowering. Only four lines (G 6, G 9, G 14 and G 15) raised from M2 generations of Meghna-2, were screened critically and observed no significant reduction in seed germination and pollen viability but the fruit size was significantly decreased. Interestingly, the short fruit type and round shape of Meghna-2 (G 9) was chosen amongst the four due to farmer’s acceptability, which was grown further to confirm the stability.

When Drosophila sperm treated with different doses of ethyl methanesulfonate (EMS) were stored in untreated females, changes in the yields of translocations and dominant lethals were examined. At high EMS doses yielding 25-33% X-linked recessive lethals, the frequencies of both translocations and dominant lethals increased markedly with increasing storage time. At low doses yielding 7-15% recessive lethals, however, no increase in their yields was detected after the storage of treated sperm, indicating that storage effects of EMS are dose dependent.

Meiotic cell division is a dynamic cellular process controlled by a large number of genes that act from premeiotic to postmeiotic mitosis. Mutation in these genes may cause anomalies that impair plant fertility. In this study, an attempt has therefore been made to understand the effects of ethyl methane sulfonate (EMS), sodium azide (SA) and gamma rays on the meiotic configuration of Delphinium malabaricum. The results demonstrated that the mutagens cause various types of cytological aberrations, such as univalents, chromatin bridges, laggards, fragments, stickiness and multinucleated cells. The maximum aberrations were found at higher doses/concentrations of the mutagens. The highest percentage of pollen mother cells showing abnormalities was induced by EMS followed by gamma rays and SA. The mutagen impact on chromosomal anomalies increased the frequency of pollen sterility.

Induced mutations are highly effective in enhancing natural genetic resources and have been used in developing beneficial variations for practical plant breeding. In the current study, dry grains of barley ( Hordeum vulgaris L., cv. Nosrat, 2n = 2x = 14) were exposed to physical and chemical mutagens. The results of Duncan multiple rang test showed that treatments of gamma ray (control (0), 200 and 320 Gy) had highest germination percentage and formed class a. The lowest germination percentage belonged to ethyl methane sulfanate (0.7%). Mean comparison of radical length trait showed that the highest radical length belonged to gamma ray control, 200 Gy and sodium azide (SA) 0.5 mM and treatments of gamma ray 700 Gy, 1200 Gy and ethylmethane sulphonate (EMS) 0.7% had lowest radical length. Mean comparison of plumule length trait showed that treatment of SA 1 mM had highest plumule length. Cytogenetic studies have shown chromosome breakage in some induced barley seed by high dose of 700 and 1200 Gy. On the basis on growth traits analysis, sodium azide 0.5, 1 and 5 mM, ethyl methane sulfanate 0.1% and gamma ray 200 and 320 Gy are appropriate mutagens. However, it needs more consideration on mutagen, dose of mutagens and trait to have best breeding program by mutagenesis. Key words : Barley, physical and chemical mutagen, gamma radiation, sodium azide, ethyl methane sulphonate.

Background: Mutation breeding is one of the important techniques for creating genetic variability and developing improved crop varieties with desirable traits. Chemical mutagens such as ethyl methanesulfonate (EMS), sodium azide (NaN3), colchicine and organic solvent dimethyl sulfoxide (DMSO) have been frequently used in plant mutation breeding programs. However, the combined effects of multiple chemical mutagens and their treatment durations on plant germination, growth and development are not well understood. Methods: This study investigated the combined effects of chemical mutagens comprising of EMS, Sodium azide, colchicine and DMSO on the germination of five commercial rice (Oryza sativa L.) hybrids in the M1 generation. Seeds were treated in the mutagen solution for varying durations ranging from 4 to 24 hours. Result: Significant differences were observed in germination rates among the hybrids and across treatment durations. The highest germination rate of 3.08% was observed in Arize 6444 Gold with a 4-hour treatment, while the lowest rate of 0.17% was recorded in Srichakra 1168 with a 24-hour treatment. Overall, germination rates decreased with increasing treatment duration, likely due to the cumulative mutagenic effects and DNA damage. Srichakra 1168 exhibited the highest tolerance to the mutagen mix, while DPS-Virat was the most sensitive. Despite the low germination rates, the surviving M1 plants may harbor a range of desirable and undesirable mutations, presenting opportunities for identifying valuable mutants with improved traits in subsequent generations. This study highlights the importance of optimizing mutagen combinations and treatment conditions to balance the induction of genetic variability with the maintenance of seed viability in mutation breeding programs for rice improvement.

Germination of rape (Brassica napus L.) seed exposed to ethyl methanesulfonate (EMS) for 12 hr at 20–25 C was differentially affected by EMS concentration, pH of treatment solution, seed size, and strain treated. All first order interactions among treatments, except EMS concentration × strain, significantly affected germination. Increasing EMS concentration from 0 to 1.0% adversely affected germination, plant vigor, and seed yield and increased the number of abnormal plants and the days to maturity in M1 populations. The types of plant abnormalities observed following EMS treatment are described.