Doses Of EMS Research Articles

Ethyl methane sulphonate -A potent mutagen for inducing genetic variability in saffron (Crocus sativus L.)

Mutagenic effects of three concentrations of ethyl methane sulphonate [EMS] (0.1, 0.15 and 0.20%) to improve floral, foliar, corm and quality attributes in saffron was evaluated. A considerable genetic variability was observed among the mutagenic lines created with 0.15 and 0.20% EMS dose with significant shift in mean values in positive direction for almost all the traits studied. Identification of 64 mutant lines from available population of 660 lines confirmed highest mutagenic frequency of 43.75% by 0.15% EMS followed by 0.2% EMS (42.18%); whereas 0.10% EMS showed least mutagenic frequency. Component analysis showed medium to high GCV values for most of the traits confirming variability of genetic nature thereby implying that clonal selection has paramount significance in the identification of elite lines. Divergence analysis grouped 92% mutagenic lines in cluster 1 followed by 6.1% in cluster 2 and 1.5% in cluster 3. Maximum contribution towards divergence of most of the traits was recorded by lines ‘SS/EMS-3/113’, ‘SS/EMS-3/132’, ‘SS/EMS-3/130’ and ‘SS/EMS-1/219’. Per se performance studies identified 18 extraordinary lines which showed significant superiority over base population for floral, foliar, corm and quality attributes and thus can be harnessed for commercial exploitation for enhancement in factor productivity per unit area.

Influence of gamma radiations and EMS on morphological characteristics of gladiolus cv. PINK BEAUTY

The corms of gladiolus cv. PINK BEAUTY were treated with gamma rays (0, 3, 6, 9 kR), EMS (0. 0.2, 0.4, 0.6 %) both alone and in combination including control i.e. untreated. Different vegetative, floral and corm parameters were recorded. The days taken for sprouting of corms were delayed after treatment with gamma rays and recorded maximum at 6 kR + 0.2 % (26.78 days). Duration of sprouting was decreased by EMS and was observed to be maximum at 3 kR gamma rays (100%). The gladiolus plants could not survive in treatments of gamma rays and its combination with EMS. On the basis of above observations, it may be concluded that 0.2 to 0.6 per cent EMS doses are suitable for inducing mutation in gladiolus.

Morpho-biochemical evaluation of EMS regenerated mutants of Bergenia ciliata (Haw.) Sternb. under in vitro conditions

The present work has been carried out with the objective to evaluate the morpho-biochemical changes in the EMS generated mutants of Bergenia ciliata before transferring them to field conditions. In this regard, range of EMS doses from 0.1% to 0.9% have been given. The present doses have shown adverse effect on seed germination, root number and decreased soluble protein content of plant. However shoot length, root length, chlorophyll content and total carbohydrate content were improved at lower doses (0.3%) of EMS treatment and decreased thereafter.

Inducible protective processes in animal systems XIV: Cytogenetic adaptive response induced by EMS or MMS in bone marrow cells of diabetic mouse

BackgroundAdaptive response has been well studied by employing physical and chemical agents in normal test systems, whereas in diseased conditions very little data are available. Aim of the studyTo know the presence or absence of adaptive response in diseased condition, alkylating agents such as EMS or MMS have been employed in diabetic mouse. Material and methodsTo induce diabetes, mice were injected with 180mg/kg body weight of Stz. Diabetic mice were treated with conditioning (100mg/kg body weight of EMS or 40mg/kg body weight of MMS), challenging (300mg/kg body weight of EMS or 160mg/kg body weight of MMS) and combined doses of EMS or MMS with 8h time lag. Parallelly controls were maintained. Mice were sacrificed at 24 or 48 or 72h RTs. Bone marrow was extracted and slides were prepared by a routine air dry technique by Evans et al. (1964) to analyze the chromosomal aberrations. ResultsThe results show that both the alkylating agents induced exclusively chromatid type of aberrations in both diabetic and non diabetic mice, but it is to be underlined that MMS is a more potent inducer of aberrations than EMS. Eventhough, combined treatment of EMS or MMS induced significantly less chromosomal breaks compared to challenging treatment (p<0.05) in diabetic mice, EMS induced 40% reduction of breaks, compared to 51.74% by MMS at 24h RT. This is true to other tested RTs. Conclusion(1) Methylating agents are a more effective inducer of adaptive response than ethylating agents in diabetic mouse. (2) Further, it is interesting to note that the percentage reduction of chromosomal breaks in diabetics is comparatively much less than in non diabetic mouse, inferring that there is variation in adaptive response between diseased and non diseased condition.

GC-MS Analysis and Evaluation of Mutagenic and Antimutagenic Activity of Ethyl Acetate Extract of Ajuga bracteosa Wall ex. Benth: An Endemic Medicinal Plant of Kashmir Himalaya, India

Herbal medicines as the major remedy in traditional system of medicine have been used in medical practices since antiquity. The natural products remain an important source of new drugs, new drug leads and new chemical entities. The ethyl acetate extract of Ajuga bracteosa was evaluated for mutagenic and antimutagenic assay against mice pre-treated with 1/4th LD50 (117.5 mg/kg bw) of ethyl methane sulphonate by micronucleus and chromosomal aberration assay. Mice were treated with ethyl acetate extract of Ajuga bracteosa (Ab-EAE) (100, 200 300 & 400 mg/kg bw) for 30 days. Without the doses of EMS, no mutagenic effects were observed in blood and bone marrow samples of the mice. But Ab-EAE showed antimutagenic effects on EMS induced mutagenicity in mice. It was observed that high doses of Ab-EAE showed protective effects. The reduction profiles in the EMS induction MN at concentration of ethyl acetate extract of Ajuga bracteosa (100, 200, 300 and 400 mg/kg bw) were estimated as 2%, 4.9%, 16.4% and 20.7% respectively. It can be concluded from the study that ethyl acetate extract of Ajuga bracteosa exhibited no mutagenic effects but only possessing antimutagenic effects. This antimutagenic activity is an induction of medicinal relevance.

Physical and chemical mutagenesis in Stevia rebaudiana: variant generation with higher UGT expression and glycosidic profile but with low photosynthetic capabilities

The leaf explants of Stevia rebaudiana were exposed to a range of EMS (chemical mutagen) and gamma radiation (physical mutagen) doses. Among all the treatments, doses of 0.4 % v/v EMS and 0.95 KR gamma radiation were found to be most effective treatment for selection of variants via direct shoot bud induction. The field-established plants designated as EMS (E), gamma (G), and control (C) plants were subjected to photosynthetic parameter studies where E and G plants showed lower chlorophyll content, transpiration rate, CO2 exchange rate, and stomatal conductance. The implanted field soil at the time of harvesting of plants showed reduction in organic carbon (OC), electrical conductivity (EC), phosphorus (P)/potassium (K), and total Kjeldahl nitrogen (TKN). The ISSR profiling of E, G, and C scored total of 107 bands out of which 63 % were polymorphic bands, and plant E was found to be more distant from the C plant phylogenetically. On phytochemical analysis, the G plant registered twofold enhanced rebaudioside A with lower stevioside (3.2 ± 0.22 % dry wt.) content, whereas E plant showed more than 1.5- and 2.0-fold increase in stevioside and rebaudioside A as compared to control plants. Both the E (3.1 ± 0.15 % dry wt.) and G (2.3 ± 0.21 % dry wt.) plants registered lower steviol. The enhanced steviol glycoside profile was supported by the RT-PCR analysis of UGT74G1 and UGT76G1 that corresponds to stevioside and rebaudioside A biosynthesis, respectively. While the E plant showed 5–6-fold increase in the UGT74G1 (RQ = 5.51 ± 0.5) and UGT76G1 (RQ = 6.61 ± 0.5) gene expression, the G plant showed 5-fold increase in UGT76G1 (RQ = 5.29 ± 0.2) gene expression.

Induced mutations in cowpea, &lt;i&gt;Vigna unguiculata&lt;/i&gt; (Leguminosae)

Two cowpea (Vigna unguiculata L. Walp).vatietiés, IT84E-124 and Vita 7 of the Intemational Inslitute ofTropícal Agriculture, Ibadan, were exposed lo Varying doses of chernieal and physical mutagens. Optimum doses of 10mM EMS for 6hr andO.l rnM aod 1.OrnM NaN3 for 2hr, determíned frorn seedling growth tests and lOOR and 2ooR,garnma radiaticins were applied 10 2000 seed samples of each ,genotype. Sereening of the M2 generation revealed, lhat the rnutagenic treatrnents indueed rnorphological, physiologie;¡land biochemicalchanges in the genotypes: A spectrum of rnutations which included variants.wilh respect t()anthocyanin pigmentatiCln, ¡ellf morphology, maturity date, male sterility and insec.tpestresístancequalitieswere observect; Unes withsignificant increases in yield parameters such as .rtumber or seeds pefpod, pedimcles per plant, 100 seed weight and seed storage proteinswere selected:

Differential response of biochemical parameters to EMS and MMS treatments and their dose effect relationship on chromosomes in induced diabetic mouse

AimTo study the effect of alkylating agents such as EMS and MMS on chromosomes and biochemical parameters in induced diabetic mouse. MethodsChromosome preparations from bone marrow was made using the method of Evans et al. (1964) and biochemical estimations from the liver was done by the method of Sinha (1972) for catalase, Van der Vies (1954) for glycogen and Uchiyama and Mihara (1978) for MDA. ResultsThe study has revealed that EMS and MMS induced a dose dependent increase in chromosomal aberrations of chromatid type in the diabetic mouse. Nonetheless, it is interesting to note that, there is significant reduction in the frequency of chromosomal aberrations in diabetic compared to non diabetic mice at all tested doses of EMS or MMS and at different recovery times [RTs]. On the other hand biochemical parameters showed a variable degree of reactivity: (1) catalase activity was significantly elevated in non diabetics whereas in diabetics it is significantly decreased with increasing concentrations of EMS. Contrary to this, the catalase activity in the case of MMS treatment is significantly reduced in non diabetics compared to diabetic mice. (2) However glycogen level is significantly reduced in both the diabetic and non diabetic with increasing concentrations of EMS or MMS, but MDA levels were significantly increased. Conclusion(1) Even though alkylating agents induce chromosomal aberrations in diabetic mice, MMS, a methylating agent is a more potent inducer of chromatid type of aberrations than EMS, an ethylating agent. (2) Diabetic mouse is more resistant than the non diabetic to alkylating agents and (3) the tested agents altered the analyzed biochemical parameters.

Frequency and Spectrum of Induced Viable Macromutations in Chickpea (&lt;i&gt;Cicer arietinum&lt;/i&gt; L.) Cultivar ‘Vishwas’

Present investigation was undertaken to study the frequency and spectrum of induced viable macromutations employing SA, EMS and gamma radiation in chickpea (Cicer arietinum L.) cultivar Vishwas (Phule G 5). The seeds of chickpea, cultivar Vishwas were treated with three different concentrations / doses of SA (2, 3 and 4 mM), EMS (8, 12 and 16 mM) and gamma radiations (400, 500 and 600 Gy). The mutagen administered seeds were sown in experimental fields to raise M1 progeny. Seeds of M1 plants and control were harvested separately and sown to raise M2 population. The M2 progeny were screened for viable macromutaions. A wide spectrum of viable macromutations was isolated in the M2 generation. In all twenty four different types of viable morphological macromutations were observed. These included 7 types of plant type mutations and 6 types of leaf mutations, 1 types of flower mutation, 5 types of pod mutation and 5 types of seed mutations. Results indicated that all mutagenic treatments were effective in inducing viable mutations in chickpea, during M2 generation. Differences in response to different mutagens were observed in the spectrum and frequency of viable mutations. Some mutation types occurred more frequently than others. The frequency and spectrum of viable mutations were relatively high with EMS followed by gamma radiation and SA. In the present investigation, an attempt has been made for increasing frequency and spectrum of locally important chickpea cultivar ‘Vishwas’ employing chemical and physical mutagens.

Frequency and Spectrum of Induced Viable Macromutations in Chickpea (&lt;i&gt;Cicer arietinum&lt;/i&gt; L.) Cultivar ‘Vishwas’

Present investigation was undertaken to study the frequency and spectrum of induced viable macromutations employing SA, EMS and gamma radiation in chickpea (Cicer arietinum L.) cultivar Vishwas (Phule G 5). The seeds of chickpea, cultivar Vishwas were treated with three different concentrations / doses of SA (2, 3 and 4 mM), EMS (8, 12 and 16 mM) and gamma radiations (400, 500 and 600 Gy). The mutagen administered seeds were sown in experimental fields to raise M1 progeny. Seeds of M1 plants and control were harvested separately and sown to raise M2 population. The M2 progeny were screened for viable macromutaions. A wide spectrum of viable macromutations was isolated in the M2 generation. In all twenty four different types of viable morphological macromutations were observed. These included 7 types of plant type mutations and 6 types of leaf mutations, 1 types of flower mutation, 5 types of pod mutation and 5 types of seed mutations. Results indicated that all mutagenic treatments were effective in inducing viable mutations in chickpea, during M2 generation. Differences in response to different mutagens were observed in the spectrum and frequency of viable mutations. Some mutation types occurred more frequently than others. The frequency and spectrum of viable mutations were relatively high with EMS followed by gamma radiation and SA. In the present investigation, an attempt has been made for increasing frequency and spectrum of locally important chickpea cultivar ‘Vishwas’ employing chemical and physical mutagens.

Effect Of Physical And Chemical Mutagens On Morphological Behavior Of Tomato (Solanum Lycopersicum) CV. “Rio Grande” Under Heat Stress Conditions.

Abstract Given the importance to tomato production under heat stress conditions in hot climates of Pakistan, the objective of this research work was to study the influence of temperature and application of physical and chemical mutagens on tomato (Lycopersicon esculentum L.,) CV. “Rio grande” Seeds were treated with chemical mutagen (Ethyl Methane Sulphonate) and physical mutagen (Gamma radiation). Plants were grown in open field conditions under day/night temperatures regimes at the experimental area of Department of Horticulture, faculty of crop and food sciences, PMAS-AAUR. The experiment was set twenty treatments and four replications in Complete Randomize Block Design. It is observed that by increasing dose of mutagens shows lethal effect and morphological parameters reduced significantly. But lower doses of EMS and Gamma radiation improve thermotolerance capacity significantly. Plants were investigated for different morphological parameters i.e Plant height, no. of leaves, leaf area, relative water contents of leaves, chlorophyll contents, cell viability (TCC Assay) and pollen germination. Among gamma rays 5Kr were the only dose which survived and bear fruits. Among EMS 4mM, 8 mM, 16mM performed better under heat stress conditions than other treatments.

Alteration in anti-oxidant defense system and protein expression in response to varied concentrations of EMS in Psoralea corylifolia

Germplasm of Psoralea corylifolia L., one of the most important endangered medicinal plants of Chinese and Indian Pharmacopeia were treated with ethyl methane sulphonate (0, 0.1, 0.25, 0.50, 0.75 and 1 %) and sampled for observations in the form of growth, non enzymatic systems and stress proteins at pre-and post-flowering stages of development. Higher concentrations of EMS showed significant (P < 0.001) inhibition in the germination percentage from 3.88 to 35.46 % at pre-flowering stage and from 4.90 to 35.97 % at post-flowering stage when compared to control. Other growth related parameters viz shoot growth and root growth also declined within increase in the dose as compared to control plants. Root growth was severely affected as compared to shoot growth. Roots showed a significant correlation with tolerance index as increasing concentration of EMS progressively inhibited the root growth. Plants developed from treated germplasm at higher doses exhibit higher activity of ascorbate peroxidase (APX), up to flowering and after that declined. Contrast to that, total soluble protein (TSP) content decreased in age and dose wise manner. The EMS dose applied and oxidative stress was correlated and derived from the increased antioxidant activities and decrease in total glutathione content from 122.75 % (GSH) and 103.29 % (GSSG) in plants raised from treated germplasm towards the post-flowering stage. Pronounced accumulation of psoralen from 10.74 to 93.24 % was observed following higher doses of EMS at post-flowering stage, where EMS induced oxidative stress-enhanced proline accumulation and lipid peroxidation. In addition, the prevalence of maximum antioxidant activity, psoralen accumulation was an efficient process in acclimatizing P. corylifolia to stress. 2-Dimensional gel electrophoresis (2D-GE) of the protein expression profile and MALDI TOF–MS revealed an expression of 20 different proteins which are associated with such functions as cellular detoxification, stress defense, psoralen production, photosynthesis, signal transduction, and cell cycle. The increase in the psoralen pool after EMS treatment proved to be a best protective antioxidant to counterbalance EMS-induced ROS detoxification and can be used as a biomarker and a scavenger in stress physiology.

Induced mutagenesis in cowpea [Vigna unguiculata(L.) Walp] var. Arka Garima

A study was undertaken in a cowpea [Vigna unguiculata (L.) Walp.] var. Arka Garima to assess the efficiency and effectiveness of physical as well as chemical mutagens and to induce viable mutation in qualitative traits which could be utilized directly or introduced into cowpea improvement programme. Germination percent decreased in general with increase in dose/concentration of mutagens. The inhibitory effect on these characters was more prominent with gamma rays than with EMS. The frequency of chlorophyll mutation increased with the increase in dose/concentration. Wide spectrum of chlorophyll mutations were obtained in the present study which includes albino, xantha, chlorina, viridis and xantha-viridis. The lower and intermediate doses of gamma rays (200 and 300 Gy) and EMS (0.25% and 0.30%) are recommended as most effective and efficient for exploring variability and isolating promising mutants. Significant morphological variability was created which include abnormalities in growth habit, leaf, flower, pod and seed coat. The frequency of morphological abnormalities increased with increase in dose of gamma rays until 300 Gy followed by a decline. However, in chemical mutagen treated population, a linear decline in frequency up to 0.35% was seen followed by increase in higher concentrations.

SMART – Sunflower Mutant population And Reverse genetic Tool for crop improvement

BackgroundSunflower (Helianthus annuus L.) is an important oilseed crop grown widely in various areas of the world. Classical genetic studies have been extensively undertaken for the improvement of this particular oilseed crop. Pertaining to this endeavor, we developed a “chemically induced mutated genetic resource for detecting SNP by TILLING” in sunflower to create new traits.ResultsTo optimize the EMS mutagenesis, we first conducted a “kill curve” analysis with a range of EMS dose from 0.5% to 3%. Based on the observed germination rate, a 50% survival rate i.e. LD50, treatment with 0.6% EMS for 8 hours was chosen to generate 5,000 M2 populations, out of which, 4,763 M3 plants with fertile seed set. Phenotypic characterization of the 5,000 M2 mutagenised lines were undertaken to assess the mutagenesis quality and to identify traits of interest. In the M2 population, about 1.1% of the plants showed phenotypic variations. The sunflower TILLING platform was setup using Endo-1-nuclease as mismatch detection system coupled with an eight fold DNA pooling strategy. As proof-of-concept, we screened the M2 population for induced mutations in two genes related to fatty acid biosynthesis, FatA an acyl-ACP thioesterase and SAD the stearoyl-ACP desaturase and identified a total of 26 mutations.ConclusionBased on the TILLING of FatA and SAD genes, we calculated the overall mutation rate to one mutation every 480 kb, similar to other report for this crop so far. As sunflower is a plant model for seed oil biosynthesis, we anticipate that the developed genetic resource will be a useful tool to identify novel traits for sunflower crop improvement.

Induction of variability through mutagenesis in opium poppy (Papaver somniferum L.)

Opium poppy (Papaver somniferum L.), an important plant of the family Papaveraceae, is valued for its extensive medicinal properties due to the presence of more than 80 different alkaloids, which are products of the polygenic interaction of different genes involved in plant metabolism. Broadening the genetic base through induced mutation is a supplementary tool that can lead to the development of genetic variability. The present study was undertaken to generate a broad genetic variability through mutation breeding using physical doses (gamma radiation of kR10 to kR50 at an interval of kR10), chemical doses (EMS of 0.2, 0.4, 0.6, and 0.8% (w/v)), and combined doses (gamma and EMS) of mutagen, and to evaluate the plants’ advance generations for different traits as well as for specific alkaloids, especially thebaine and codeine. The kR30 dose, which caused the highest results for all 3 genetic parameters (GCV, h2, and GA%) for 7 traits, was the most effective in NBRI-1. Similarly, the kR10 + 0.4% EMS dose proved to be the best for NBRI-5, affecting 10 different characters. The kR10 + 0.4% EMS dose created positive mutations for high thebaine and codeine content and low morphine content, while the kR40 + 0.6% EMS dose did the same for narcotine. The study also confirmed that the pathway of morphinan alkaloids and narcotine formation was bifurcated at the lower combined dose (kR30 and kR10 + 0.4% EMS), which was effective in causing micromutation in morphinan alkaloid pathways. The higher combined dose (kR40 + 0.4% EMS) affected narcotine production.

Effect of Mutagens on Frequency and Spectrum of Viable Mutations in Horsegram (Macrotyloma uniflorum (Lam.) Verdc)

The seeds of horsegram (Macrotyloma uniflorum (Lam.) Verdc) cv. Dapoli Kulthi1 were subjected to gamma radiation (100, 200, 300 and 400Gy), EMS (0.2, 0.3, 0.4 and 0.5 %) and combination treatments. The mutations affecting gross morphological changes in plant habit, leaf and pod morphology, and maturity were scored as viable mutations. These mutants were characterized and named on the basis of specific characters constantly observed in them throughout the course of investigation. Effect of mutagens on the frequency and spectrum of different types of viable mutations in M2 generation were recorded. The high frequency of mutations in terms of mutants per 1000 M2 plant population was observed in low doses of EMS (0.2%), gamma radiation (100Gy) as well as in their combination (400Gy +0.4% EMS). The range of viable mutations in gamma radiation, EMS and their combinations was 0.61 to 2.16%, 0.62 to 2.98% and 0.21 to 1.81% respectively. Spectrum of viable mutations included desirable characters like early maturity, tall and dwarf habit, profuse branching, increased leaf area, higher number of pods, grains and grain weight were used to select desirable mutants.

Chlorophyll Fluorescence Spectra as an Indicator of X-Ray+EMS-Induced Phytotoxicity in Safflower

The present investigation deals with the study of in vivo laser-induced chlorophyll florescence spectra (LICF) of safflower leaves (Carthamus tinctoriusL.) for X-rays+EMS-treated plants. Seeds were treated with different doses of X-ray+EMS (5, 8, 12, 25, and 30 Kr+0.5% EMS) and were grown in the green house. The effects of the concerned treatment on chlorophyll (Chl) contents and Chl fluorescence were investigated after 7 days of germination. Results obtained revealed that the values of Chl contents, intensity of Chl fluorescence spectra, and fluorescence intensity ratio (FIR) F685/F730 are directly correlated with the treatment doses monitored. The treatment sets of 8, 12, and 25 Kr + 0.5% EMS doses showed an increase in FIR and thereby a decrease in the Chl contents. However, the lowest treatment dose of 5 Kr + 0.5% showed a decrease in FIR and thereby an increase in chlorophyll contents. Safflower seeds treated with 30 Kr + 0.5% EMS were proved to be lethal as they showed no germination. Thus, our study demonstrates early detection of chlorophyll damage caused by various physical and chemical mutagens through the application of LICF spectra.

Effect of Gamma Rays and EMS on Two Varieties of Soybean

A study was undertaken on induced mutagenesis with CO1 and CO2 varieties of soybean. The mutagens studied were gamma rays (20, 30, 40, 50 and 60 kR) and EMS (5, 10, 15, 20 and 25 mM). In an assessment to fix the LD50 value, the varieties responded differently. A subtle difference was observed between the varieties CO1 and CO2 in the degree of tolerance to the mutagens, viz., CO1, (62 kR gamma rays, 26.4 mM EMS) and CO2 (58.3 kR gamma rays and 25.7 mM EMS). It is concluded that CO1 tolerate higher doses of gamma rays and EMS. In general, the treated population had manifested a reduced expression than the untreated population in all the biometrical traits. Reduction in phenotypic expression is linear with the dose or concentration of the mutagens in M1 generation. The mutagen gamma ray manifested higher percentage of reduction than EMS. In M2, EMS induced higher proportion of chlorophyll mutants than gamma rays. Among viable mutants, sterile mutant occurred more predominantly followed by stunted growth in both the varieties due to the effect of mutation. Induced mutations delivered fairly good amount of genotypic coefficient of variation, the heritability, GA as percent of mean with respect to number of seeds per plant, seed yield per plant and hundred seed weight for both the mutagen in both the varieties, indicating the scope for improving the soybean yield by selection. The mutants with four seeded pods, bold seeded types and increased number of pods per plant were isolated from this experiment

Adaptive response to alkylating agents in the Drosophila sex-linked recessive lethal assay

The adaptive response to alkylating agents was studied in Drosophila assays under various treatment procedures. Pre-treatment of males as well as treatment of females with low doses of EMS (0.05–0.1 mM) did not affect sex-linked recessive lethal (SLRL) rates induced by high doses of this mutagen (10 mM, various feeding duration) in mature sperm cells. Pre-treatment of males with a low dose of MMS (0.1 mM) enhanced mutagenesis induced by the high dose of EMS (10 mM) at different stages of spermatogenesis, the observed effects exceeding the additive action of both mutagens. On the contrary, larval pre-treatment with the adaptive dose of EMS (0.05 mM) resulted in resistance of their germ cells to higher doses of EMS (1 mM). Specifically, offspring production increased while dominant lethality in F 1 as well SLRL frequency in F 2 was significantly reduced as compared with the effects of larval exposure to the challenge dose. Under the conditions tested, the adaptive response of germ cells to alkylating agents was demonstrated in larvae, but not in adult flies.

The Effects of Different Doses of Gamma Ray and EMS on Formation of Chlorophyll Mutations in Durum Wheat (Triticum durum Desf.

The Effects of Different Doses of Gamma Ray and EMS on Formation of Chlorophyll Mutations in Durum Wheat (Triticum durum Desf.