M2 Generation Research Articles

Correlation and path coefficient analysis studies in mutant PVK 801 genotype of sorghum (Sorghum bicolor (L.) Moench)

Mutation was induced in sorghum cultivar ‘PVK 801’ with the help of gamma rays and EMS. The experimental material comprised of different mutagenic treatments treated with different concentrations viz., 0.1%, 0.2%, 0.3% were EMS treatments and 10 kR + 0.1% EMS, 20 kR + 0.1% EMS, 30 kR + 0.1% EMS and 40 kR + 0.1% EMS were combination treatments and dry and wet control treatments were evaluated for correlation and path analysis for the grain yield and some of the independent traits in M2 generation. All these treatments were grown in randomized block design with three replications during Kharif 2019. The correlation studies revealed that positive and significant genotypic and phenotypic correlation of grain yield per plant with number of primaries per panicle, flag leaf area and 100 seed weight. The characters exerted direct positive effect on grain yield per plant with days to panicle initiation, days to maturity, plant height (cm), number of primaries per panicle, panicle length (cm), panicle width (cm) and 100 seed weight. Hence these traits can be considered as selection indices for sorghum improvement programme. The component of residual effect of path analysis was 0.4298.

Selection of mutant short stem M5 from 200 Gy gamma ray irradiation on Mentik Susu rice

Mentik Susu rice is one of Indonesian local rice variety that is less attractive to farmers because of its high stems and low yield. One method of using physical mutagen is gamma ray radiation. The purpose of this research is observing the performance of mutated M5 generation of mentik susu rice which already irradiated with 200 Gy gamma ray and selecting the short-stemmed ones which have high productivity. The research was conducted in Novermber 2018-April 2019 on Palur Village, Mojolaban, Sukoharjo Regency. The experiment was done by planting 35 individual M5 and control seeds. The variables observed were plant height, harvest age, number of productive tillers, panicle intensity index, seed yield per plant. Data were analyzed descriptively and compared the performance of mentik susu rice M5 with control via T test analysis. The results showed that there was a difference in the performance of the M5 mutants of mentik susu rice as result of 200 Gy gamma ray irradiation compared to control mentik susu rice. There are 22 selected mutant plant individuals in the M-MS2-G15T3-5-2(18,25,16,8)strains; M-MS2-G15T3-4-15(10)strains; M-MS2-G15T3-2-5(56,18,9)strains; M-MS2-G18T7-4-4(11)strains; M-MS2-G18T7-4-12(15,13,18)strains; M-MS2-G17T17-13-9(23,21,29)strains; M-MS2-G18T7-4-9(17,12)strains; M-MS2-G15T3-2-18(35)strains; M-MS2-G15T3-2-14(28,61,36)strains; and M-MS2-G18T3-6-13(35)strains.

Selection of M5 short-stemmed mutants from 200 gray gamma ray irradiation in Mentik Wangi rice

Mentik Wangi rice is native to Indonesia, it has an oval round shape of rice, yellow brown rice, and fragrant aroma. Mentik Wangi has a weakness that is relatively long harvest time, the plant is too high so it easily fell. This research aims to determine the performance of M5 generation of mutant rice and to select M5 generation of mutant plants resulted from 200 gray gamma irradiation which has short stems with high productivity. The research was carried out by planting 36 genotypes, namely 35 M4 lines of 200 gray gamma ray irradiation and control plant (without irradiation). Observation data were analyzed descriptively and t test to determine differences in M5 generation of Mentik Wangi rice from 200 gray gamma ray irradiation with control plants (without irradiation). Based on the research results that Mentik Wangi rice plants with gamma ray irradiation 200 Gray have better performance compared to control plants (without irradiation) and there are 28 individuals M5 Mentik Wangi rice mutants selected by short-stemmed plants and have high productivity.

Perfomance selection of Mentik Wangi M5 generation rice resulting from 100 gray gamma-ray irradiation

Mentik Wangi rice is local rice originating from Yogyakarta Indonesia, which has distinctive fragrant and fluffier texture. The problems that occur in Mentik Wangi rice cultivation are that the harvest time is longer, and the plants are too high so that it gives a potential lower production impact because it is easy to collapse. One way to overcome this problem is through plant breeding with gamma-ray irradiation. The aim of this research is to select Mentik Wangi M5 irradiated by 100 Gy gamma-ray, which has a short stem and has high productivity. Observation data were analyzed descriptively, followed by a T-test to compare the performance of Mentik Wangi M5 rice plants from 100 gray gamma irradiation with control plants (without irradiation). The shortest plant height is in the M-MW1-G12-01-18–05 of 96cm with a height range of 96–110 cm. The highest number of productive tillers was found in the M-MW1-G80-11-08-15 with a range of 15–25 tillers. The highest panicle density index range was found in the M-MW1-G35-02-06-19 of 4.6-6.77. The highest level of plant productivity was found in the M-MW1-G12-01-18-01 which was 5.95 tons/ha. The results of the selection there are 21 individual plant mutans.

Characterization of chlorophyll deficient mutants in mungbean (Vigna radiata (L.) Wilczek)

A wide spectrum of chlorophyll mutants was obtained in M2 generation following mutagenesis with MMS, HZ and SA. All these chlorophyll deficient mutants were lethal except maculata, viridis and virescent. MMS treatments induced the highest frequency of chlorophyll mutations followed by HZ and SA. The frequency of chlorophyll mutations was dose dependent and increased with increasing concentrations of all the three mutagens utilized. Chlorina followed by xantha outnumbered the other types of chlorophyll mutants with all the three mutagens. Based on effectiveness, the order of mutagens was HZ > SA > MMS. Two criteria viz., pollen sterility (Mp/S) and seedling injury (Mp/I) were taken into consideration to determine the efficiency of the mutagens. With regard to these criteria, MMS mutagen was found to be the most efficient followed by HZ and SA. Lower concentrations of all the three mutagens were most effective and efficient in inducing chlorophyll mutations.

Study of mutation induced by Sodium Azide in field pea (Pisum sativum L.)

The present study was conducted to determine the effect of Sodium Azide's sensitivity (0.1%, 0.3% and 0.5%) on three genotypes of field pea viz., Makhyatmubi, Makuchabi, and Rachna. In M1 generation, a dose-dependent decrease was observed for seed germination, seedling height and plant survival. The pollen fertility showed a negative dependence on Sodium Azide's dose as evident from proportionate decrease in fertility with the mutagen's increasing concentration in all the three varieties. The loweest pollen fertility was noted in a Makuchabi (83.76%) at 0.5% Sodium Azide. The four types of chlorophyll mutation (chlorina, xantha, albina, and viridis) were screened from the M2 population. Chlorina type of mutation was induced with the highest frequency at all the concentrations regardless of the variety studied. The greater concentration of Sodium Azide was observed to induce an extensive range of chlorophyll mutation in all the genotypes. However, the overall spectrum of chlorophyll mutation induced in field pea was in the following order; chlorina > viridis > xantha > albina. The magnitude of mutagenic effectiveness exposed a variety of response; it decreased with the increasing concentration of Sodium Azide on the varieties Makhyatmubi and Rachna, while on the other hand a rising trend of it was observed in the case of Makuchabi. Sodium Azide's efficiency for most of the treatment decreased with increase in the concentration in genotypes of Makhyatmubi and Rachna but for Makuchabi, it increased with the concentration in a decreasing trend.

INDUCED GENETIC VARIABILITY IN SESAME (Sesamum indicum L): A COMPARATIVE STUDY ON THE MUTAGENIC EFFECTS OF RADIATION AND EMS IN SEED GERMINATION, POLLEN VIABILITY AND CHLOROPHYLL MUTANTS

The present study envisaged the effects of two mutagens, gamma rays and EMS on the phenotypes of two sesame varieties viz., TMV7 and SVPR1. A known quantity of dry, uniform, and healthy seeds of TMV7 and SVPR 1 were irradiated using Co60 (Cobalt 60) with different doses (250, 300, 350, 400, 450 Gy) of gamma rays. For chemical mutagenesis, different concentrations of EMS @ 0.20%, 0.40% and 0.60% was used and treated for 8 h. The dose-response curve of the probit analysis showed that the optimal lethal dose for SVPR1was lower than TMV7. The expected LD50 values of gamma radiation for TMV 7 and SVPR1 were 403.91Gy and 343.84Gy, respectively. For EMS, the expected LD50 values are 0.525 % and 0.276% for TMV7 and SVPR1 respectively. Germination and pollen fertility declined linearly with an increase in dose or concentration of the mutagens. Three classes of chlorophyll mutants viz., xantha, chlorine, and viridis in M2 generation reveals a dose dependent relationship between mutagens and frequency of chlorophyll mutants. Mutagenic effectiveness was higher at lower doses whereas mutagenic efficiency was observed higher at extremity doses in both the varieties. The overall considerations on M1 generation effects showed that SVPR1was highly sensitive to gamma rays and TMV7 produced more viable mutationsthan SVPR1. The current studies suggest gamma rays as an efficient mutagen to induce essential mutations in TMV7 for the further crop improvement program.

Radiation sensitivity of sesame (Sesamum indicum L.) genotypes in M1 generation

The present study investigated the gamma ray sensitivity of two sesame (Sesamum indicum L.) varieties viz., SVPR1 and TMV7 irradiated with five different doses from 250 Gy to 450 Gy at 50 Gy intervals. Germination percentage, root and shoot length, pollen fertility (%) decreased gradually and observed a dose dependent relationship with an increase in dosage of gamma rays. Survival percentage recorded irregular decreasing trend with upsurge in survival rate at certain doses. SVPR1 showed a pronounced maximum reduction in germination percentage (37.5%) than TMV7 (40.05) at 450 Gy, whereas survival percentage of TMV7 (20.02%) and SVPR1 (19.5%) was drastically reduced at 250 Gy itself. At a higher dose of 450 Gy, root (3.08) and shoot (3.03) length of seedlings of SVPR1 were greatly inhibited. Pollen fertility percentage showed a linear reduction irrespective of the genotypes, and maximum reduction was rear at 450 Gy in SVPR1 (62.76%) was recorded. LD50 values that showed 50% reduction in biological parameters differed between TMV7 and SVPR1. Based on all the biological parameters studied, the mutagen sensitivity of SVPR1 is higher than TMV7. The overall considerations on M1 generation effects showed that SVPR1 were highly sensitive to gamma rays.

Mutagenic Effectiveness and Efficiency in [Vigna unguiculata (L.) Walp.] Variety Phule Phandari (PP) and VCM-8

Background: Mutation breeding is one of the cheapest and surest method of plant breeding. In mutation breeding program effectiveness and efficiency of mutagens could be helpful to realize the spectrum of desirable mutations in the treated populations. The effectiveness and efficiency of two mutagens EMS and gamma rays were studied in two varieties of cowpea [Vigna unguiculata (L.)Walp.]. Methods: In the present investigation, the seeds of two varieties of cowpea, phulepandhari and VCM-8 were treated with gamma rays and EMS to obtain the spectrum and frequency of chlorophyll mutations in M2 generation. Mutagenic effectiveness and efficiency were calculated using frequency of chlorophyll mutations.Result: The individual treatment of EMS was found to be more efficient than gamma rays to induce chlorophyll mutants. A progressive increase in mutation frequency of chlorophyll mutations was observed with increasing doses. Four different types of chlorophyll mutants, such as, chlorina albina, xantha and viridis were induced with effect of mutagens. The highest frequency of chlorophyll mutations was reported in the gamma rays. There was a dose dependent increase in the spectrum and frequency of chlorophyll mutations. The lower dosages of gamma rays and EMS were proved to be most effective and efficient. Among two mutagens used EMS was much more effective than gamma rays in both the varieties viz. variety phulepandhari and VCM-8.

Morphological characteristics and yield performance of mutant soybean [Glycine max (L.) Merr.] M6 genotypes in Jatinangor, Sumedang, West Java

Current breeding efforts in soybean largely focus on identifying genotypes with high seed yield and large seed size. Our study applied a mutation using 250 Gy Gamma-Ray Irradiation to soybean cv. Anjasari. The variability in the M1 generation was identified, and the planting was continued to M2 M3, M4, M5 until M6 generation. The objectives of this research were to evaluate mutant lines exhibiting a good performance in yield and morphological characteristics that can support the yield component in M6 generation. This research was conducted from January 2019 to May 2019 at Ciparanje Experiment Station, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, West Java. The experiment was arranged in a Randomized Completely Block Design with fifteen mutant soybean genotypes as treatments with two replications within each treatment. The results showed several genotypes produced higher yield and better agro-morphological characteristics. The genotypes MR-33, MR-4A, and MR-2A showed significantly higher number of total pods per plant. Meanwhile, the genotypes MR-35A, MR-37, MR-23, MR-36A, MR-3A, MR-29A MR-34A, MR-4A, MR-17, and MR-5A showed a higher value in weight of 100 seeds. The highest yield was observed in MR-29A and MR-23, which then will be used as the genotypes for multilocation test for stability.

Effects of Mutagens on Morphological traits of Psoralea corylifolia-A Medicinally Important Plant

Mutation breeding like in other plants can significantly strengthen medicinal plants breeding programs and help to produce novel varieties with higher yield potential and improved yield quality. The dry and healthy seeds of P. corylifolia IC 111228 were subjected to mutagenic treatments namely ethyl methane sulphonate (EMS) and sodium azide (SA). The treatment concentrations 15mM, 30mM, 45mM and 60mM of EMS and 1mM, 2mM, 3mM and 4mM of SA were chosen to evaluate the mutagenic potential in either case. The morphological traits were evaluated in M1 generation viz. plant height, days to flowering initiation, seed yield/plant and 100-seed weight. In EMS treatment 15 mM increased the plant height and seed yield, while in SA treatment 4 mM increased the seed yield/plant and 100-seed yield.

Comparative Studies on Mutagenic Effectiveness and Efficiency in Horsegram [Macrotyloma uniflorum (Lam) Verdc.

Background: Two horsegram varieties viz., PAIYUR 2 and CRIDA1-18R were mutated with gamma rays (G), electron beam (EB), G+EB and G+EMS (ethyl methane sulphonate) to determine the mutagenic potency in breeding programme.Methods: Uniform seeds treated with different mutagenic doses were raised in randomized block design which constituted M1 generation. Each plant was harvested individually and forwarded to M2 generation following plant to progeny row method.Result: A dose dependant decline was observed for seed germination, plant survival, root length, shoot length, plant height, pollen fertility and seed fertility in M1 population. Wide spectrum of chlorophyll mutants was induced in M2 generation with maximum frequency at EB followed by combination treatments (G+EMS and G+EB) in both varieties. The mutagenic effectiveness ranged from 0.14 per cent to 1.45 per cent in PAIYUR 2 and 0.15 per cent to 1.71 per cent in CRIDA1-18R. The high mutation rate for effectiveness was exhibited by G and G+EB. With reference to sterility, EB was found to be efficient mutagen in both varieties whereas varied efficiency was noted for lethality (EB - PAIYUR 2; G+EMS - CRIDA1-18R) and injury (G - PAIYUR 2; G+EMS - CRIDA1-18R).

Technical note: Gamma irradiation induces changes of phenotypic and agronomic traits in wheat (Triticum turgidum ssp. durum)

Wheat varCIRNO C2008 was irradiated with gamma rays at 100, 200, and 300 Gy. The irradiated plants obtained at 300 Gy (M1) showed a significant reduction (compared to M0 plants) in germination (i.e. 3.8% at day 5), survival percentage (48%), and plant height (63.3%). Thus, the Probit analysis showed an LD50 of 287.80 Gy. Besides, these irradiated plants, in the field, showed a significant increase (compared to M0 plants) in days to spike initiation (16 days), and maturation (14 days). On the other hand, in the field, fourteen chlorophyll mutants were found (at a different frequency) in the M2 generation, such as Albina, Anthocyanin, Chlorina, Maculata, Tigrina, Striata, Viridis, Viridoalbina, Alboviridis, Xantha, Xanthviridis, Xanthalba, Viridoxantha, and Orange stem. In addition, mutants with changes in agronomic and morphological traits were observed. This nuclear technique is an alternative to obtain promising mutant lines that can be used directly as a variety and/or as parental to transfer these traits to other varieties.

Morphological variations of wheat (Triticum aestivum L. em. Thell.) under variable ethyl methanesulphonate mutagenesis

Genetic gains in wheat yield have stagnated over the years due to genetic drift. There is a need to create new genetic variation for yield using various methods including ethyl methanesulphonate (EMS). The use of EMS mutagenesis is limited by variations in lethality, efficiency and effectiveness, which confound to selection. The objective of this study was to evaluate morphological variation in wheat after EMS mutagenesis. Wheat genotype LM43 was subjected to EMS mutagenesis under the following conditions: 0.1% v/v for 1 h at 25 °C, 0.1% v/v for 1 h at 30 °C and 0.7% v/v for 1.5 h at 25 °C. Some mutant plants in M1 had significantly (p < 0.05) higher spikelets per spike and kernels per spike. The number of tillers and kernels per spike increased significantly at M2 generation. EMS treatment with 0.1% v/v for 1 h at 30 °C was the most effective and efficient with the lowest biological damage. Macro-mutations were observed in spike, peduncle, awn and flag leaf morphology. The study identified early generation mutants that could be exploited for improving drought tolerance, yield and biomass, or for genetic analysis to identify quantitative trait loci in wheat.

IMPROVING YIELD AND SEEDS IN OKRA CROP THROUGH INDUCED USEFUL MUTATIONS

Cultivation of okra in Egypt is challenged by low yield due to lack of improved cultivars. Gamma irradiated okra seeds can generate genetic variability to improve the crop. Field experiment was carried out in a private farm at Sidy salim distrect, Kafr El-Sheikh Governorate, Egypt during 2017, 2018 and 2019 seasons. Samples of dry seeds each of two okra cultivars Balady and Sabahia were irradiated with different doses of gamma rays (0, 10, 20, 30 and 40 KR) and variability in growth characteristics, earliness and pod yield were investigated in M1, M2 and M3 generations. Data were statistically analyzed for all the levels of significance. For significant F ratios New Duncan's Multiple Range (DMRT). The results of this investigation showed that the M1 plants exhibited different degrees of reduction in growth in comparison with those of the untreated control plants. In M2-generation, 26 different mutant lines were selected. Analysis of variance in M3 generation showed a highly significant difference among M3 lines and control for vegetative and agronomical traits of two okra cultivars. Among 26 M3 lines, one mutant line was produced higher pod yield (29.4 g/plant) compared with control plants (14.6 g/plant). This line will be being to evaluated for the desired traits and wide adaptability to biotic and abiotic stress to obtain new variety with high yield and good quality. Conclusively, Induced mutation is a valuable breeding tool for inducing new genetic recombination and selectsuseful lines with desired traits in okra. The present study made an extensive phenotypic evaluation from M1 to M3 generations which enabled us to select promising mutant lines with higher pods yield in M3generation. These lines could be valuable genetic resources for genetic improvement and breeding of okra in Egypt. Further selection and improvement are needed for testing mutant lines for adaptability and stability under different environments under large-scale production for releasing new improved okra cultivars.

Mutagenic efficiency and effectiveness of gamma rays and EMS in groundnut (Arachis hypogaea L.)

An experiment was conducted to retrieve some useful chlorophyll mutants in two groundnut varieties of TMV (Gn)13&nbsp;and TMV 7. The mutagenic efficiency and effectiveness were calculated by using the chlorophyll mutants. In M1&nbsp;generation, the seedling height was decreased with an increased rate of doses/concentration while lethality and pollen&nbsp;sterility were increased with an increased rate of doses/concentration in both the varieties on both the treatments. In&nbsp;the present study, the chlorophyll mutants were observed in M2. The four different chlorophyll mutants observed were&nbsp;albino, chlorina, xantha and striata at different crop stages of crop growth. On perusal of data, it was inferred that&nbsp;chlorina occurred at large followed by xantha and albino. Mutagenic effectiveness were significantly higher in gamma&nbsp;rays for TMV(Gn)13 and TMV 7 (4.24 and 2.64) than the EMS which registered as 3.69 and 2.19 respectively. The&nbsp;mutagenic efficiency was increased for injury and decreased for lethality and pollen sterility with an increased rate of&nbsp;doses/ concentration.

High TARC plasma levels confer protection to long living individuals by inducing M2 profile

A way to delay aging and the related low-grade chronic inflammatory state is to study the model of positive physiology such as the Long-Living Individuals (LLIs). Our recent studies have shown higher levels of the host defense BPI Fold-Containing Family B Member 4 (BPIFB4) protein in the LLIs’ blood. Notably, BPIFB4 has been shown to influence monocytes typesetting and M2 anti-inflammatory phenotype (CD206+CD163++) macrophages skewing.According to the role of a complex cytokine milieu in guiding the macrophage polarization, here we found that circulating concentrations of thymus and activation regulated chemokine (TARC)/CCL17 and small-inducible cytokine B10 (IP-10)/CXCL10) cytokines, were additionally associated with the LLIs’ state.In a differentiation process in vitro, the addition of LLIs’ plasma to the cell culture medium, enhanced the ability of monocytes, either from LLIs or controls, to acquire a M2 phenotype. Interestingly, a neutralizing antibody against TARC blunted the M2 skewing effect of the LLIs’ plasma. Collectively, these data indicate that exceptional longevity may associate with a peculiar anti-inflammatory myeloid profile responsible for improved reparative processes and reduced inflammatory status mediated in part by TARC and M2 generation.

Mutant Selection Short-stem of M2 Generation Mentik Wangi Rice Resulted from Irradiation with Gamma-ray.

Mentik Wangi is local rice variety from Magelang, Central Java. This rice has superior properties, which is tender texture, has fragrant, but also has a long harvesting age and tall stems so that it easily collapses during heavy wind. The purpose of this study was to determine the performance of M2 mutants resulting from 150, 200 and 250 Gy gamma irradiation and to find out the plants to obtain short-stemmed, short-lived mutant plants with high productivity. The tools used in this study include tractors, hoes, rakes, sickles, stakes, code boards, gauges, rulers, raffia, scissors, analytical scales, newspapers, stationery. The materials used are M2 generation Mentik Wangi rice seeds which are the result of 250 Gy gamma-ray irradiation, control Mentik Wangi rice seeds (without radiation), urea fertilizer, Ponska, SP36, KCl, ZA and pesticides. Plant treatment includes weed control, irrigation, fertilization, pest and disease control and put nets to avoid bird attacks. The study was conducted using a simple design experiment. The results showed the difference between Mentik Wangi rice M2 generation gamma-ray irradiation with control plants. The results of the selection of short-trunked mutant plants, short-lived and have high productivity. M2 selection obtain 11 plants mutant from irradiation with 150 Gy, 22 plants mutant from irradiation with 200 Gy and 24 plant mutant from irradiation with 250 Gy that have short stems and high productivity.

Setaria viridis chlorotic and seedling-lethal mutants define critical functions for chloroplast gene expression.

Deep insights into chloroplast biogenesis have been obtained by mutant analysis; however, in C4 plants a relevant mutant collection has only been developed and exploited for maize. Here, we report the initial characterization of an ethyl methyl sulfonate-induced mutant population for the C4 model Setaria viridis. Approximately 1000 M2 families were screened for the segregation of pale-green seedlings in the M3 generation, and a subset of these was identified to be deficient in post-transcriptional steps of chloroplast gene expression. Causative mutations were identified for three lines using deep sequencing-based bulked segregant analysis, and in one case confirmed by transgenic complementation. Using chloroplast RNA-sequencing and other molecular assays, we describe phenotypes of mutants deficient in PSRP7, a plastid-specific ribosomal protein, OTP86, an RNA editing factor, and cpPNP, the chloroplast isozyme of polynucleotide phosphorylase. The psrp mutant is globally defective in chloroplast translation, and has varying deficiencies in the accumulation of chloroplast-encoded proteins. The otp86 mutant, like its Arabidopsis counterpart, is specifically defective in editing of the rps14 mRNA; however, the conditional pale-green mutant phenotype contrasts with the normal growth of the Arabidopsis mutant. The pnp mutant exhibited multiple defects in 3' end maturation as well as other qualitative changes in the chloroplast RNA population. Overall, our collection opens the door to global analysis of photosynthesis and early seedling development in an emerging C4 model.

Resistance level of several soybean lines of M6 generation to stem rot disease Athelia rolfsii

Abstract. Hanafiah DS, Safni I, Siregar LAM, Famanik RIM, Lestmi A, Matondang M. 2020. Resistance level of several soybean lines of M6 generation to stem rot disease Athelia rolfsii. Biodiversitas 21: 4537-4542. Athelia rolfsii (Curzi) C.C. Tu &amp; Kimbr. is a soil-borne pathogen that causes stem rot disease on plants. The attack is one of the causes of low soybean productivity hence induction of plant resistance is needed to overcome these problems. Mutagenesis is one of the breeding techniques for inducing genetic variability especially for disease-resistant characters in soybean. This research aimed to obtain selected soybean plant lines (Glycine max L. Merr) of M6 generation based on resistant character against stem rot disease A. rolfsii. This research was conducted at the Laboratory of Plant Disease and research field of Faculty of Agriculture, Universitas Sumatera Utara, Medan, Indonesia and soybean planting was carried out on agricultural field, Universitas Sumatera Utara from March to September 2018. This research used augmented design. The treatments were 8 mutant genotypes derived from radiation mutagenesis, that is; Anjasmoro, Argomulyo, and Kipas Putih varieties. The results showed that the analysis of resistant levels on M6 generation based on disease incidence resulted in 2 lines with resistant criteria to stem rot disease A. rolfsii, that is; M100A25 (5/3) and M200A11 (32/3). Observation of intensity of disease attacks showed that Anjasmoro, Argomulyo, M100A6 (31/1), and M200A12 (6/5) had the lowest resistance level compared to other genotypes. The mutant lines that had high category level of resistance are candidates for resistance lines against stem rot disease A. rolfsii.