M1 Plants Research Articles

Induced mutagenesis for resistance to mungbean yellow mosaic virus and yield traits in mungbean

The M0 ѕeedѕ of mungbean variety DGGV 2 treated with different doѕeѕ of ethyl methane ѕulphonate (EMЅ) at 0.1%, 0.2% and 0.3% concentrations were assessed for Mungbean Yellow Mosaic Virus (MYMV) in M2 generation during summer 2023 at University of Agricultural Sciences, Dharwad. Considering the yield superiority over check (Mean + 2 Standard Deviation) and highly resistant response to MYMV disease, out of 962 M2 plants 17 superior M2 plants were identified. The seed yield plant-1 in these identified mutants ranged from 21.9 to 32.0 g which is higher compared to the average yield of check DGGV 2 (11.7 g) during that season. Also, the other yield contributing traits such as number of productive branches, number of cluster plant-1, number of pods cluster-1, and number of pods plant-1 were observed to be higher in these mutants in comparison to check variety.

Evaluation of the Impact of Chemical Mutagens on the Phenological and Biochemical Characteristics of Two Varieties of Soybean (Glycine max L.).

Mutagenic effectiveness and efficiency are the most important factors determining the success of mutation breeding, a coherent tool for quickly enhancing diversity in crops. This study was carried out at Lovely Professional University's agricultural research farm in Punjab, India, during the year 2023. The experimental design followed a randomized complete block design (RCBD) with three replications. The experiment aimed to assess the effect of three chemical mutagens, sodium azide (SA), ethyl methyl sulphonates (EMSs), and methyl methane sulfonate (MMS), at three different concentrations (0.2%, 0.4%, and 0.6%), in SL958 and SL744 soybean varieties to select the mutant exhibiting the highest yield. The data were collected and analysed using a two-way ANOVA test through SPSS software (version 22), and the means were separated using Duncan's multiple range test (DMRT) at the 5% level of significance. Between the two varieties, the highest seed germination percentage (76.0% seedlings/plot) was recorded in SL958 (0.4% SA), while the lowest (30.33% seedlings/plot) was observed in 0.6% MMS as compared to the control (53% and 76% in SL744 and SL958 at 10 days after sowing, respectively). Several weeks after sowing, the average plant height was observed to be higher (37.84 ± 1.32 cm) in SL958 (0.4% SA) and lower (20.58 ± 0.30 cm) in SL744 (0.6% SA), as compared to the controls (SL958: 26.09 ± 0.62 cm and SL744: 27.48 ± 0.74 cm). The average leaf count was the highest (234.33 ± 3.09 tetrafoliate leaves/plant) in SL958 (0.4% SA) while it was the lowest (87 leaves/plant) in 0.6% MMS as compared to the control (SL744 180.00 ± 1.63 and SL958 160.73 ± 1.05). The highest total leaf areas recorded in the SL958 and SL744 M1plants were 3625.8 ± 1.43 cm2 and 2311.03 ± 3.65 cm2, respectively. Seeds of the SL958 variety treated with 0.4% SA resulted in the development of tetrafoliate leaves with a broad leaf base and the maximum yield (277.55 ± 1.37 pods/plant) compared to the narrow pentafoliate leaves obtained through the treatment with EMS. Meanwhile, in the SL744 variety, the same treatment led to tetrafoliate leaves with a comparatively lower yield of 206.54 ± 23.47 pods/plant as compared to the control (SL744 164.33 ± 8.58 and SL958 229.86 ± 0.96). The highest protein content (47.04 ± 0.87% TSP) was recorded in the SL958 (0.4% SA) M2 seeds followed by a content of 46.14 ± 0.64% TSP in the SL744 (0.4% SA) M2 seeds, whereas the lowest content (38.13 ± 0.81% TSP) was found in SL958 (0.6% MMS). Similar observations were recorded for the lipid and fibre content. The 0.4% SA treatment in SL958 proved to be efficient in generating the highest leaf area (tetrafoliate leaves) and a reasonable yield of M1 (the first generation after mutation) plants.

Development of Two Tossa Jute Mutants for Higher Fiber Yield Through Mutation Breeding

The demand for jute fiber is increasing instead of synthetic fiber nowadays. Developing an early and high fiber-yielding tossa jute line is the main breeding objective of jute growing areas including Bangladesh. To fulfill that objective, the existing cultivar JRO-524 was irradiated with five (700, 800, 900, and 1000 gy) doses of gamma-ray. A total of 25 M3 plants were first selected from bulked M2 plants. Two years of replicated yield trial experiments were conducted in different locations in Bangladesh. Among them, two mutants BJM-10-1-3 and BJM-10-1-5 were selected for higher fiber and stick yield. The selected mutants BJM-10-1-3 and BJM-10-1-5 showed 4% to 6% higher yield than their parent JRO-524. The mutant line BJM-10-1-5 showed higher fiber percentage (34.04%), fiber fitness (2.65%), and fiber brightness (44.15%). These two mutants have been under participatory varietal trial (PVT) for evaluation to release a tossa jute variety. These lines will play a vital role in reducing the seed import of variety JRO-524 from India. Vol. 10, No. 3, December 2023: 259-268

Gamma Irradiation Doses reduce Cooking time and Improve Nutritional Profile of selected Pigeon pea [Cajanus cajan (L.) Millsp] Genotypes in Nigeria

Pigeon Pea (Cajanus cajan L.) is a self-pollinating perennial legume shrub with over 30,000 accessions deposited world-wide. Despite the nutritional importance of pigeon peas, its detrimental traits such as its long cooking time, has led to low cultivation of the crop and inhibit its consumers’ request. Concerted efforts to improve both the quality and quantity of this crop through mutation breeding informed this research. It was based on this premise that the study was aimed to evaluate gamma irradiation influences on the nutrient quality and cooking duration of selected pigeon pea varieties in Nigeria. Four accessions of pigeon peas (‘NG/SA/11/08/108’, ‘NG/AO/MAY/00/021/01’, ‘TCC-2’ and ‘NG/SA/07/191’) were obtained from National Centre for Genetic Resources and Biotechnology (NACGRAB), Ibadan. They were irradiated at the Oncological Department ABU Teaching Hospital, Shika, Zaria, using Cobalt-60 (60CO) irradiation source. Standard procedures were followed to determine the effects of the irradiation on cookability and nutritional profile of the M1 plants and their respective controls. It was established that all the parameters tested were irradiation dose dependent. In NG/AO/MAY/00/021/01, 100 Gy produced the highest protein (20.40 %) and highest carbohydrate (68.93 %) contents. Anti-nutritional factors such as cyanide were lower (48.83, 46.22, 43.65 and 44.75 mg/kg in NG/AO/MAY/00/021/01, NG/SA/11/08/108, NG/SA/07/191 and TCC-2) at 400 Gy than those of their respective controls (54.83, 56.83, 53. and 53.55 mg/kg). The amount of Magnesium increased with higher doses of gamma irradiation (1.37 g/100 g for 200 Gy NG/AO/MAY/00/021/01; 1.03 g/100g for 400 Gy NG/SA/11/08/108 and 1.13 g/100 g for TCC-2). There were significant reductions in cooking time in 400 Gy treatments for all the genotypes. The differences between the control and the least cooking time in 400 Gy were 11, 16, 22 and 15 minutes for NG/AO/MAY/00/021/01, NG/SA/11/08/108, NG/SA/07/191 and TCC-2, respectively. It was therefore concluded that these variations could be exploited for further improvement of the crop for food security. Keywords: Cooking time, Mutation breeding, Gamma irradiation, Cookability, Dose dependent

Investigation of Chlorophyll Mutations in Gamma Irradiated Naked Barley Genotypes

The consumption of naked barley is significantly increasing as more people become aware of its benefi-cial role as a source of dietary fiber and β-glucan. As a result, breeding programs paid more attention to naked barley. Improvement of yield and quality of naked barley is hindered by the lack of available germplasm. Mutation breeding is an effective tool for generating variation for plant breeding. Chlorophyll mutations are often used as visual indicators in breeding research to determine the optimum mutagen dosage. The purpose of this study was to identify the types and frequency of chlorophyll mutations brought on by different gamma radiation doses in two genotypes of hulless barley and determine the effective dose (ED50) based on the mutation frequency. Seeds of naked barley line YAA7050-14 and cv. Yalin that have been irradiated with doses of 100, 150, 200, and 300 Gy gamma rays delivered by a Cobalt-60 source. Chlorophyll mutations were observed in 8-day-old M2 plants grown under greenhouse conditions. In the M2 plants of cv. Yalin, the highest mutagen frequency was observed at 250 and 300 Gy, while in line YAA7050-14, the highest mutation frequency was found at 300 Gy. The rate of chlorophyll mutation rose in both genotypes as the gamma ray doses increased. The albino type of chlorophyll muta-tion was found in the cv. Yalin at the greatest rate, whereas the xantha type was found in the line YAA7050-14. The most common chlorophyll mutation type was albino, while the least common type was viridis when both genotypes were considered together. Based on the mutation frequency, 250-300 Gy doses could be used to effectively in further research to create mutations in the naked barley genotypes.

Agro-Morphological Traits and Molecular Diversity of Proso Millet (Panicum miliaceum L.) Affected by Various Colchicine Treatments

Colchicine is a substance used to induce mutations in order to regulate important agronomic traits. The genotypes Pavlodarskoe 4, Quartet, and PI 289324, originating from Kazakhstan, the Russian Federation, and Hungary, respectively, were used as materials. The objective of this study was to investigate the effects of different colchicine concentrations (0.0, 0.04, 0.06, 0.08, and 0.1%) and treatment times (6, 12, and 24 h) on the agronomic traits of proso millet (Panicum miliaceum L.) and to assess the genetic diversity of the M2 generation using inter simple sequence repeat (ISSR) markers. The experiment was conducted in 2021 for the M1 generation and in 2022 for the M2 generation, from May to September. The percentage of field germination decreased with increasing colchicine concentrations and exposure durations. The mean field germination percentages were 48.57% in Pavlodarskoe 4, 43.28% in Quartet, and 53.14% in PI 289324 under colchicine treatment. Chlorophyll-defective M1-M2 plants were obtained using various colchicine concentrations and exposure periods. The highest number of mutational modifications was attained with the 0.08–0.1% concentrations of colchicine. Based on the research results, a total of 248 plants with chlorophyll-defective mutations were selected from 2214 plants. The growing seasons of M1 and M2 plants were shortened by higher colchicine concentrations (0.08–0.1%) combined with soaking times of 12 and 24 h. Thus, the longest growing season (84 days) was observed with a 6 h treatment time for PI 289324, while the shortest (78 days) was recorded for 12 and 24 h treatments. The possibility of obtaining morphological mutations using colchicine has been confirmed. The ISSR primers amplified a total of 1333 fragments; 1281 bands were found to be polymorphic, and 52 bands were monomorphic. The percentage of polymorphism varied from 80 to 100%, with an average of 96.11%. Most of the different allelic bands were detected when applying the 0.08% colchicine concentration. These positive variations are a great opportunity to use colchicine as a tool for improving agronomic traits in plant breeding.

MiRiQ Database: A Platform forIn Silico Rice Mutant Screening.

Genetic studies using mutant resources have significantly contributed to elucidating plant gene function. Massive mutant libraries sequenced by next-generation sequencing technology facilitate mutant identification and functional analysis of genes of interest. Here, we report the creation and release of an open-access database (https://miriq.agr.kyushu-u.ac.jp/index.php), called Mutation-induced Rice in Kyushu University (MiRiQ), designed for in silico mutant screening based on a whole-genome-sequenced mutant library. This database allows any user to easily find mutants of interest without laborious efforts such as large-scale screening by PCR. The initial version of the MiRiQ database (version 1.0) harbors a total of 1.6 million single-nucleotide variants (SNVs) and InDels of 721 M1 plants that were mutagenized by N-methyl-N-nitrosourea treatment of the rice cultivar Nipponbare (Oryza sativa ssp. japonica). The SNVs were distributed among 87% of all 35,630 annotated protein-coding genes of the Nipponbare genome and were predicted to induce missense and nonsense mutations. The MiRiQ database provides built-in tools, such as a search tool by keywords and JBrowse for mutation searches. Users can request mutant seeds in the M2 or M3 generations from a request form linked to this database. We believe that the availability of a wide range of gene mutations in this database will benefit the plant science community and breeders worldwide by accelerating functional genomic research and crop improvement.

Effect Of Viable Mutants In M2 Generation Of Urdbean Vigna Mungo (L.) Hepper Through Induced Mutation In Variety ADT 3 and Co 6

Mutations were induced in Black gram (Vigna Mungo (L.) Hepper) varieties namely ADT 3 and Co- 6. Seeds treated with gamma rays doses at 200, 300 and 400 Gy and Electron beam viz., 200, 300 and 400 Gy and combined treatment (Electron beam + gamma rays) 200+200, 300+300 and 400 +400 Gy. Different types of Macro mutants and micro mutants were screened in M2 generation. The frequency and the spectrum of the viable mutants were estimated in M2 generation both in M1 plants basis and M2 seedling basis. The highest frequency of viable mutants was recorded in ADT 3.The highest number of mutants was recorded in electron beam followed by Gamma rays and combined treatment (Electron beam + gamma rays). The present study reveals good scope for isolation of suitable morphological traits mutants induced may be useful in breeding programmes for the improvement of blackgram with agronomically desirable character which force is utilized in future breeding programme.

Impact of gamma radiation on the agronomic properties of naked barley genotypes

The usage of naked barley in the food industry is increasing day by day due to its health benefits. As a result, research on breeding naked barley have gained popularity. In these breeding studies, a wide variation in desired traits is needed to achieve higher success in selection. One of the best methods for obtaining genotypic variation, which is crucial for breeding studies on naked barley, is mutation. To obtain genotypic variation in certain agronomic parameters in naked barley genotypes, the impact of different gamma radiation doses on M1 and M2 plants of two naked barley genotypes was evaluated in this research. The seeds were treated with gamma irradiation using Cobalt 60 gamma source at six different doses, along with non-irradiated control samples. While the values at low doses were found to be comparable to the control in the majority of the traits, 250-300 Gy caused significant decreases in the majority of the traits in the M1 generation of both genotypes. Plant height, number of spikelets per spike, and number of grains per spike at the M2 generation were all negatively impacted by 250–300 Gy, although spike length, grain weight per spike, and thousand grain weight were positively impacted by the same doses. The mutant population generated by gamma irradiation of seeds of different naked barley genotypes was found to have suitable variation for the selection of desired traits. In addition, this material can be used to select individuals with outstanding agronomic characteristics.

Induction and Characterization of Mutations Related to Dwarf Habit in Hardy Hibiscus (Muenchhusia section)

Hybrids between various species of Hibiscus in the Muenchhusia section are popular in commercial markets due to their colorful, floriferous blooms. However, many commercial cultivars are too vigorous for use in smaller garden spaces and often have only a few flowers in bloom. Stable, heritable mutants exhibiting dwarf stature and better branching architecture will be valuable to the commercial production of hardy Hibiscus. The goal of this project was to induce stable, heritable mutations using ethyl methanesulfonate that result in increased branching and a dwarf compact phenotype and introgress the compact phenotypes into lines of hardy Hibiscus to generate a series of diverse compact cultivars for use in commercial markets. Multiple mutations associated with dwarf, compact phenotypes were successfully induced. Hybridizations were made between M2 plants displaying a dwarf phenotype and hybrids developed through conventional breeding that do not possess the dwarf mutation in their background to develop diverse selections of dwarf plants. Inheritance patterns of the dwarf genes were determined through the segregation ratios of the dwarf phenotype in the F1 and F2 generations of these hybrids. Compared with wild-type progeny, dwarf progeny had shorter internode lengths and a greater number of primary branches.

M2 plants derived from different tillers of a chemically mutagenized rice M1 plant carry independent sets of mutations.

Generation of mutant populations with high genetic diversity is key for mutant screening and crop breeding. For this purpose, the single-seed descent method, in which one mutant line is established from a single mutagenized seed, is commonly used. This method ensures the independence of the mutant lines, but the size of the mutant population is limited because it is no greater than the number of fertile M1 plants. The rice mutant population size can be increased if a single mutagenized plant produces genetically independent siblings. Here, we used whole-genome resequencing to examine the inheritance of mutations from a single ethyl methanesulfonate (EMS)-mutagenized seed (M1 ) of Oryza sativa in its progeny (M2 ). We selected five tillers from each of three M1 plants. A single M2 seed was selected from each tiller, and the distributions of mutations induced by EMS were compared. Surprisingly, in most pairwise combinations of M2 siblings from the same parent, ≥85.2-97.9% of all mutations detected were not shared between the siblings. This high percentage suggests that the M2 siblings were derived from different cells of the M1 embryo and indicates that several genetically independent lines can be obtained from a single M1 plant. This approach should allow a large reduction in the number of M0 seeds needed to obtain a mutant population of a certain size in rice. Our study also suggests that multiple tillers of a rice plant originate from different cells of the embryo.

Genetic variability of mutant rice (Oryza sativa) genotype induced by gamma rays

Abstract. Ishak I. 2023. Genetic variability of mutant rice (Oryza sativa) genotype induced by gamma rays. Biodiversitas 24: 3300-3306. Rice seeds of Sidenuk cultivars were irradiated by gamma rays creating a broad spectrum of genetic variability among individual plants at M3 generation progeny. Gamma Irradiated seeds created Mutation among the somatic cells population in mature embryos at M1 generations. Somatic cell mutation influenced the genetic structures of gametes cells formation on gametogenesis at M1 plants. Observation of M2 plants showed that black and brown colors of rice's pericarp were found with rice's lemma, and palea color was different compared to the wild type (Sidenuk cultivars). Seven plants with black rice pericarp colors out of 330 were obtained at M2 plants. Chlorophyll mutation was observed at M4 generation; the results showed that chimera, green, and albino leaf blade was obtained in several individual plants. There were also the variability of Palea and lemma colors among individual plant such as green, white, and purple. The cellular biology approach will explain these mutations before molecular biology identification is made.

Determination of Optimum Gamma Ray Irradiation Doses for Hulless Barley (Hordeum vulgare var. nudum L. Hook. f.) Genotypes

The limited germplasm resources of hulless barley restrict the breeding of hulless barley with improved traits. Mutation techniques are an effective tool for generating variation for plant breeding studies. This study aimed to evaluate the impact of gamma-ray at different doses on certain seedling properties of M1 plants of two hulless barley genotypes, as well as determine the effective dose (ED50). The seeds of two hulless two-row barley genotypes, cv. Yalin and hulless barley line YAA7050-14, were irradiated with 100, 150, 200, 250, and 300 gray Gamma-rays delivered by a Cobalt 60 source along with non-irradiated control samples. Gamma-ray irradiation affects the seedling properties of M1 plants of both hulless barley genotypes significantly. The significant effect varied based on the doses, traits, and genotypes. While lower doses were found statistically identical to the control in the majority of qualities in the M1 generation, 250-300 gray gamma ray doses caused statistically significant decreases in the majority of characteristics studied in both genotypes. The effective doses (ED50) for hulless barley genotypes were determined by plotting growth reduction values of seedling lengths, then the polynomial regression equations were calculated for each genotype. It was determined that 50% growth reduction in shoot length was reached at 214.1 Gy and 253.4 Gy for cv. Yalin and line YAA7050-14, respectively.

Generating homozygous mutant populations of barley microspores by ethyl methanesulfonate treatment

AbstractInduced mutations are important for genetic research and breeding. Mutations induced by physical or chemical mutagenesis are usually heterozygous during the early generations. However, mutations must be fixed prior to phenotyping or field trials, which requires additional rounds of self-pollination. Microspore culture is an effective method to produce double-haploid (DH) plants that are fixed homozygotes. In this study, we conducted ethyl methanesulfonate (EMS)-induced mutagenesis of microspore cultures of barley (Hordeum vulgare) cultivar ‘Hua30’ and landrace ‘HTX’. The EMS concentrations were negatively correlated with the efficiency of callus induction and the frequency of mutant plant regeneration. The two genotypes showed different regeneration efficiencies. The phenotypic variation of the regenerated M1 plants and the presence of genome-wide nucleotide mutations, revealed by whole-genome sequencing, highlight the utility of EMS-induced mutagenesis of isolated microspore cultures for developing DH mutants. Genome-wide analysis of the mutation frequency in the regenerated plants revealed that a considerable proportion of mutations resulted from microspore culture (somaclonal variation) rather than EMS-induced mutagenesis. In addition to producing a population of 1972 homozygous mutant lines that are available for future field trials, this study lays the foundation for optimizing the regeneration efficiency of DH plants and the richness of mutations (mainly by fine-tuning the mutagen dosage).

Multi-generation study of heavy ion beam-induced mutations and agronomic trait variations to accelerate rice breeding.

Heavy ion beam (HIB) is an effective physical mutagen that has been widely used in plant mutational breeding. Systemic knowledge of the effects caused by different HIB doses at developmental and genomic levels will facilitate efficient breeding for crops. Here we examined the effects of HIB systematically. Kitaake rice seeds were irradiated by ten doses of carbon ion beams (CIB, 25 - 300 Gy), which is the most widely used HIB. We initially examined the growth, development and photosynthetic parameters of the M1 population and found that doses exceeding 125 Gy caused significant physiological damages to rice. Subsequently, we analyzed the genomic variations in 179 M2 individuals from six treatments (25 - 150 Gy) via whole-genome sequencing (WGS). The mutation rate peaks at 100 Gy (2.66×10-7/bp). Importantly, we found that mutations shared among different panicles of the same M1 individual are at low ratios, validating the hypothesis that different panicles may be derived from different progenitor cells. Furthermore, we isolated 129 mutants with distinct phenotypic variations, including changes in agronomic traits, from 11,720 M2 plants, accounting for a 1.1% mutation rate. Among them, about 50% possess stable inheritance in M3. WGS data of 11 stable M4 mutants, including three lines with higher yields, reveal their genomic mutational profiles and candidate genes. Our results demonstrate that HIB is an effective tool that facilitates breeding, that the optimal dose range for rice is 67 - 90% median lethal dose (LD50), and that the mutants isolated here can be further used for functional genomic research, genetic analysis, and breeding.

Mutation induction in aromatic Joha rice of Assam for improvement of morpho-agronomic traits through M1 to M3 generation

Purpose The popular Joha rice cultivar Kon Joha, cultivated throughout the state, was used to induce mutations. Kon Joha is short-grain aromatic rice with excellent cooking quality. The cultivar is tall and late maturing with an average yield of less than 2 tons ha−1 and is susceptible to lodging Materials and methods The investigation through M1 to M3 generation aimed at improving the morpho-agronomic traits of the popular Joha rice cultivar Kon Joha. The experiments were carried out during the Sali season (winter rice) from 2017 to 2019 at Instruction-cum-Research (ICR) Farm of Assam Agricultural University, Jorhat (Assam). Dry uniform seeds of Kon Joha were subject to irradiation with 100–400 Gy of gamma rays from a 60Co source. The M1 generation used a randomized complete block design with four replications during Sali 2017. A total of 5998 M1 plant progenies were subject to screening in the M2 during Sali 2018. The M3 included 662 morpho-agronomic variants raised in the plant rows during Sali 2019, and 66 mutants were confirmed. Results The M1 of Kon Joha registered a reduction in germination, seedling height, pollen/spikelet fertility and plant survival at 400 Gy. All the traits showed highly significant differences among the doses in the M2 generation. The shift in trait means was in both directions as influenced by the genotype and mutagen dose. The 66 mutants exhibited significant differences for all traits in the M3 generation. Fifty mutants were shorter than the parent Kon Joha. The GCV and PCV estimates were high (>20%) for grain yield, biological yield, productive tillers, filled grains, and average panicle weight. All the traits except panicle length exhibited high heritability coupled with high genetic advance, suggesting the predominance of additive gene action and the effectiveness of simple selection. Grain yield showed a significant positive correlation with plant height, panicle length, filled grains, spikelet fertility, the average panicle weight and harvest index in the mutant population. Conclusions Thus, mutation induction in Kon Joha proved useful in inducing desirable changes in plant architectural traits. The study further emphasized the short stature high yielding mutants with strong aroma for wide-scale testing in the state.

Induced Mutagenesis and Variability Study in the M2 Generation of Garden Pea (Pisum sativum L.)

Background: Mutation induction in garden pea (Pisum sativum L.) aimed to study the induced genetic variability and identify desirable mutants in the M2 generation with two varieties of garden pea, Kashi Nandini and Kashi Uday. Methods: The two varieties of garden peas, Kashi Nandini and Kashi Uday, were subjected to mutagenic treatments with the EMS at 0.05, 0.10, 0.15, 0.20, 0.30 and 0.40%. The M1 generation was raised in RBD with two replications during Rabi 2019-20. Plants from three concentrations, 0.10, 0.15 and 0.20% EMS, were evaluated in M1 plant progenies (M2) during Rabi 2020-21. The M2 was raised during Rabi 2020-21 in M1 plant progenies using M1 plants from three concentrations -0.10, 0.15 and 0.20% EMS of both varieties. Result: The two varieties that were exposed to EMS responded differently depending on the concentrations. The GCV and PCV were high for seedling height, fertile branches, pods/plant and seeds/pod in both parents at 0.15 and 0.20% EMS. The highest heritability and genetic advance were apparent for seedling height and seeds/pod at 0.10 and 0.20% EMS, while the estimates were moderate for seeds/pod with 0.20% EMS, followed by seeds/pod at 0.10% EMS and seedling height at 0.20% EMS. Desirable plants were visible for various quantitative traits in the M2 generation. These mutants showed significant differences from the controls of both varieties in the treated populations at higher concentrations of EMS. Desirable micro mutants in M2 resulted at 0.15 and 0.20% EMS, which need further evaluation in the M3 for confirmation.

Specific Gibberellin 2-Oxidase 3 (SbGA2ox3) Mutants Promote Yield and Stress Tolerance in Sorghum bicolor

Sorghum (Sorghum bicolor (L.) Moench) is a raw material that can be used as food, feed, bioenergy, and wine; it is also a gramineous crop with drought, salt, waterlogging, and high temperature resistance. However, liquor-making sorghum faces the disadvantages of having a narrow genetic basis, poor resources, and few high-quality varieties. Ethyl methane sulfonate (EMS) is a common alkylating agent that can react with one or more bases to alkylate and cause changes in the molecular structure of DNA, thereby causing mutations. It has a minimum effect on organisms and the highest efficiency. The obtained mutant populations are of great significance for cultivating new plant varieties and enriching plant germplasm resources. Therefore, in this study, ‘Hongyingzi’ a liquor-making sorghum variety, was studied using seeds treated with 0.5% EMS and 415 M3 generation plants were obtained. (1) Investigation and statistical analysis of agronomic traits in mutant libraries showed that in the M3 generation, nine important phenotypic mutant lines were obtained, including plant type, leaf blade, spike, glume, growth period, fertility, plant height, and drought resistance. The variation frequency from high to low was as follows: glume color (75.42%) > spike type (54.70%) > spike shape (47.23%) > chaff coating degree (28%) > plant growth period (23.86%) > plant height (23.61%) > absorption degree (16.14%) > branchiness (10.84%) > leaf color (4.58%) > tillering (2.16%). (2) The PCR sequencing of SbGA2ox3 from 415 sorghum M3 plants revealed that the mutation frequency of SbGA2ox3 was 1/99.02 kb. Eight plants underwent mutations, but only one line experienced missense mutations of different amino acid types, changing Ser/Ala/Val/Leu/Gln/Ser/Pro/Ala to Asn/Thr/Gly/Val/Gln/Ala/Ser. The mutant line also had shorter plant height, reduced glume coating degree, and enhanced drought resistance. The constructions of the sorghum mutant library widened the sorghum germplasm library and provided a method for sorghum breeding with a molecular basis for the functional verification of related genes and the analysis of related regulatory networks.

Generation of Sesame Mutant Population by Mutagenesis and Identification of High Oleate Mutants by GC Analysis.

Sesame is one of the important oilseed crops in the world. Natural genetic variation exists in the sesame germplasm collection. Mining and utilizing the genetic allele variation from the germplasm collection is an important approach for seed quality improvement. The sesame germplasm accession, PI 263470, which has a significantly higher level of oleic acid (54.0%) than the average (39.5%), was identified by screening the entire USDA germplasm collection. The seeds from this accession were planted in a greenhouse. Leaf tissues and seeds were harvested from individual plants. DNA sequencing of the coding region of the fatty acid desaturase gene (FAD2) confirmed that this accession contained a natural mutation of G425A which may correspond to the deduced amino acid substitution of R142H leading to the high level of oleic acid, but it was a mixed accession with three genotypes (G/G, G/A, and A/A at the position). The genotype with A/A was selected and self-crossed for three generations. The purified seeds were used for EMS-induced mutagenesis to further enhance the level of oleic acid. A total of 635 M2 plants were generated from mutagenesis. Some mutant plants had significant morphological changes including leafy flat stems and others. M3 seeds were used for fatty acid composition analysis by gas chromatography (GC). Several mutant lines were identified with high oleic acid (70%). Six M3 mutant lines plus one control line were advanced to M7 or M8 generations. Their high oleate traits from M7 or M8 seeds harvested from M6 or M7 plants were further confirmed. The level of oleic acid from one mutant line (M7 915-2) was over 75%. The coding region of FAD2 was sequenced from these six mutants, but no mutation was identified. Additional loci may contribute to the high level of oleic acid. The mutants identified in this study can be used as breeding materials for sesame improvement and as genetic materials for forward genetic studies.

The Effects of Different Gamma-Ray Doses on Safflower (Carthamus Tinctorius L.) Varieties on Agricultural Features Observed in M1 and M2 Plants

The research was carried out with the ionizing radiation source Cobalt 60 (Co-60) at a dosage of 200, 300, 400, 500 Gy on three safflower varieties. According to the results of the research, in M1 plants; in parallel with the increase in gamma dosages, a certain decrease occurred in plant height, number of branches per plant, number of trays per plant, diameter of the tray, number of seeds per tray, seed yield per plant, and seed vitality. In field observations taken from M2 plants, significant diversity was observed. In M2 plants, significant reductions in emergence rate were observed in all three cultivars depending on the increase in dosages. In all three safflower cultivars, plant height, tray diameter, number of seeds per tray and thousand seed weight values increased compared to control plants in parallel with the increase in dosages. Significant mutations were observed in the 200-400 Gy dosage range in all three cultivars. In M1 plants, when the seed yield per plant and the rate of viability were examined, a certain level of decrease was observed in parallel with the increase in gamma dosages. In M2 plants, in parallel with the dosage increase in all cultivars, the tray diameter values increased compared to the control. Again, in all cultivars, while the diameter of the tray decreased in M1, it increased in M2 in general and increases were observed at low gamma dosages. In M2, dosages of 300-400 Gy also increased in the criteria examined compared to the control and had a stimulating effect. The investigated properties generally decreased in M1 depending on the dosage increase, while there were fluctuations in M2. As a result, the variation created by the radiation and the real effect of the mutation applications emerged after M2. In this study, while the averages of Dinçer and Remzibey cultivars in terms of viability in M1 were almost the same, Shifa cultivar gave more successful results in terms of viability. When the values obtained in the study were examined, it was concluded that genetic variations and changes occurred at dosages of 300-400 Gy at most.