Chlorophyll Mutations Research Articles

Spectrum and frequency of macro and micro mutations induced through gamma rays in traditional rice landraces of Chhattisgarh

Mutation breeding offers a simple and effective means of inducing genetic variation followed by trait selection to improve the traditional rice landraces. Gamma ray induced mutagenesis is most commonly used to obtain chlorophyll mutants and economically useful mutants in many crops. In the present study, gamma ray induced (300Gy) mutagenesis was carried out in the three rice landraces viz., Samundchini, Vishnubhog and Jhilli to study the frequency and spectrum of macro and micro mutations. Macro mutations including four categories of chlorophyll mutations along with many viable mutations viz. mutants with reduced height, reduced maturity duration, high tillers, clustered grain type, dark green leaves, strong stem and grassy types were identified in the M2 population. A total of 81, 98 and 51 putative macro mutants were observed in Samundchini, Vishnubhog and Jhilli with mutation frequency (%) 0.591, 0.796 and 0.434, respectively. Furthermore, 45, 56 and 32 chlorophyll mutants with the 0.382, 0.455 and 0.272 mutation frequency percentages were observed in the M2 population of Samundchini, Vishnubhog and Jhilli, respectively. In addition, 36, 42 and 19 viable morphological mutants with the mutation frequency percentages (based on M2 population) 0.263, 0.341 and 0.162 were identified in Samundchini, Vishnubhog and Jhilli, respectively. Also, variations in mean, widening of the range and increase in the coefficient of variation for most of the quantitative traits in mutagen treated populations as compared to control depicts the existence of micro-mutation and release of polygenic variability in all the three mutagenic populations. Many economically important mutants were identified in all three landraces which could be further advanced for varietal development and use in the breeding program. Key words: Rice landraces, gamma rays, mutation breeding, mutation frequency, macro and micro mutations

Outcome of UV-B exposure and induction of some chlorophyll phenodeviants in two important hepatoprotective ethnomedicinal wild plants.

Present piece of work has been performed with an aim to engender genetic variations in Andrographis paniculata (Burm f.) Nees and Phyllanthus niruri L. since both plants own low or very poor genetic variations due to wild nature. A. paniculata and P. niruri both are magnificent hepatoprotective wild medicinal plants which have been used since ancient times as an ethnomedicine to cure several common and chronic ailments with the high competence and less side effects. UV-B radiations induce mutations because they are absorbed by major biomolecule predominantly by proteins and nucleic acids chiefly DNA. Owing to enormous potential as herbal medicines, both plants i.e. Andrographis and Phyllanthus have been selected for mutation breeding experiments using Ultraviolet-B radiations (UV-B) as a mutagen. When germinating seedlings of A. paniculata and P. niruri were reached up to 1–3 cm, they were treated with UV-B radiations for 0 min, 10 min, 20 min and 30 min with a recovery period of one hour at room temperature and were planted in earthen pots in triplicates. During observations, significant variations in growth and pigment content have been observed in both plants (A. paniculata and P. niruri) in a dose based manner. A wide spectrum of chlorophyll phenodeviants (chlorophyll deficient mutants) in M2 generation such as xantha, xanthoviridis, alboviridis, virscent and chlorina mutants in A. paniculata and variegated plant, xanthoviridis, xantha and albino mutants in P. niruri have also been observed. Out of all the chlorophyll mutants obtained, few were lethal hence not survived later, while rest were survived till different stages of development. On the basis of occurrence of chlorophyll phenodeviants in Andrographis and Phyllanthus, mutagenic effectiveness and efficiency of different doses of UV-B rays have been indexed. The practice of indexing of effectiveness and efficiency of any mutagen is being used for the successful execution of mutation breeding programs to find the optimum dose that may facilitate induction of a multitude of other lucrative mutations.

SlRCM1, which encodes tomato Lutescent1, is required for chlorophyll synthesis and chloroplast development in fruits

In plants, chloroplasts are the sites at which photosynthesis occurs, and an increased abundance of chloroplasts increases the nutritional quality of plants and the resultant color of fruits. However, the molecular mechanisms underlying chlorophyll synthesis and chloroplast development in tomato fruits remain unknown. In this study, we isolated a chlorophyll-deficient mutant, reduced chlorophyll mutant 1 (rcm1), by ethylmethanesulfonate mutagenesis; this mutant produced yellowish fruits with altered chloroplast development. MutMap revealed that Solyc08g005010 is the causal gene underlying the rcm1 mutant phenotype. A single-nucleotide base substitution in the second exon of SlRCM1 results in premature termination of its translated protein. SlRCM1 encodes a chloroplast-targeted metalloendopeptidase that is orthologous to the BCM1 protein of Arabidopsis and the stay-green G protein of soybean (Glycine max L. Merr.). Notably, the yellowish phenotype of the lutescent1 mutant can be restored with the allele of SlRCM1 from wild-type tomato. In contrast, knockout of SlRCM1 by the CRISPR/Cas9 system in Alisa Craig yielded yellowish fruits at the mature green stage, as was the case for lutescent1. Amino acid sequence alignment and functional complementation assays showed that SlRCM1 is indeed Lutescent1. These findings provide new insights into the regulation of chloroplast development in tomato fruits.

Efficiency of electron beam over gamma rays to induce desirable grain-type mutation in rice (Oryza sativa L.)

Purpose Rice is the predominant crop of Tamil Nadu state, India that occupies about 30% of the total cropped area. However, grain type and quality are the critical traits that determine the market value and domestic consumption rice variety. Most of the households of Tamil Nadu, India prefer to consume medium slender to fine grain type of rice. Hence, the present study was conducted to induce medium slender grain type in popular rice variety ADT 37 (Aduthurai 37), a short bold rice variety using gamma rays (GR) and electron beam (EB) mutagens. Materials and methods Healthy, dried seeds (12.0% moisture content) of ADT 37 rice variety were exposed to various doses of GR (100–500 Gy) and EB (200–600 Gy). The irradiated population were maintained up to M4 generation by plant to progeny row basis to identify stable mutants for grain-type variation. The selected grain-type mutants (medium slender- and slender-type mutants) in M4 generation were characterized for phenotypic and grain quality traits. Results A high frequency of desirable grain-type variation was observed in EB-irradiated population than gamma-irradiated population. A total of 25 grain-type mutants (long slender and medium slender) were obtained in M4 generation of ADT 37 variety. The morphological characterization and cooking quality assessment of the ‘grain-type’ mutants revealed that six out of 25 mutants viz., M-3 (Mutant-3), M-5, M-9, M-10, M-13 and M-15 recorded single plant yield of more than 30 g. There was non-significant variation in yield per plant (g) among the mutants and control (parent) due to key changes in grain type and thousand grain weight. Conclusion EB showed higher mutation frequency, mutagenic effectiveness and efficiency than the GR in inducing both chlorophyll and viable mutants. This study revealed that the percentage contribution of the EB was 2.57 times higher than that of GR in obtaining desirable slender and medium slender grain-type mutants. The grain-type mutants obtained in the present study can be either directly released as variety or used as parents in hybridization program of rice crop improvement.

Determination of morphological changes using gamma irradiation technology on capsicum specie varieties

Abstract The recent increase in the demand of hot and chili pepper at local, national, and international market has drawn the interest of breeders’ crop improvement researchers globally. Thus, there is a need to enhance its breeding and development to improve the production of hot and chilies pepper in the quest for food quality and security. This study focused on the germination ability and evaluation of chlorophyll mutations in M2 generation of gamma irradiates on pepper cultivars. The materials used in this experiment were obtained from the M1 generation of gamma-irradiated seeds of pepper cultivars (Capsicum frutescens, Capsicum chinense, and Capsicum annuum (hot pepper, bonnet pepper, and bell pepper, respectively)). Seeds of the pepper varieties were subjected to doses of gamma ray (i.e., 0, 100, 150, 200, 250, 300, 350, and 400 Gy) after which they were planted, raised, and harvested in the M2 generation. The parameters evaluated were germination percentage, survival percentage, epicotyl height, and chlorophyll mutations. However, the highest chlorophyll mutation frequency was observed in C. frutescens. This showed that it was more sensitive to gamma irradiation relative to C. chinense and C. annuum. virescenes were the highest chlorophyll mutant observed in all the three cultivars, while the least was Xanthan. The effective dose ranges between 50 and 250 Gy for germination and survival rate for the three cultivars of pepper give higher desirable mutations in the pepper cultivars. While 400 Gy recorded most efficient for chlorophyll mutation.

Effectiveness and efficiency of electron beam in comparison with gamma rays and ethyl methane sulfonate mutagens in cowpea

Cowpea is the poor man's crop that lacks variability due to its autogamous nature. Induced mutation serves as a potential source in the induction of variability in crops. On the other hand, the effectiveness and efficiency of mutagens will vary between species and even varieties. In the present study, a novel mutagen electron beam was used in cowpea for the first time along with commonly used mutagens gamma rays (physical) and ethyl methanesulfonate (chemical). The biological damages on eight quantitative characters in M1 generation and chlorophyll mutants in M2 generation were recorded. Two popular varieties viz., P 152 and VBN 1 constituted as the biological material of study. The rate of reduction in biological damage on quantitative characters was directly proportional to the dose of mutagen irrespective of the varieties and mutagens used. Physical mutagens showed the highest biological damage (EB- 37.5% and G- 37.3% overall reduction from control) than chemical mutagen (EMS- 30.4%). Comparing the physical mutagens at similar doses, 200 Gy or 300 Gy of electron beam showed more biological damage than 200 Gy or 300 Gy of gamma rays. Eleven different types of chlorophyll mutants were identified in the M2 generation. Xantha is the most occurred chlorophyll mutants (44.44%), while aurea and yellow viridis have least occurred mutants. Chemical mutagen (EMS) is considered to be the most effective (6.47%) and efficient mutagen (27.09%) based on the chlorophyll mutants and it was followed by an electron beam and gamma rays. Among the physical mutagens, electron beam showed the highest biological damage (37.50% overall reduction from control) and higher effectiveness and efficiency (3.80% and 23.38%) compared to gamma rays (1.87% and 13.38%). Hence, the electron beam can also be used as an effective mutagen in creating variation in cowpea and other crops as it is highly effective, cost less and safe mutagen.

Induction of mutation through gamma irradiation in non-basmati aromatic ‘badshabhog’ rice (Oryza sativa L.)

Induction of several types chlorophyll and viable morphological mutations were studied in M2 generation of non-basmati aromatic Badshabhog rice in all five different doses (200, 250, 300, 350 and 400 Gy) of gamma rays. Chlorophyll frequency was increased with increasing dose of gamma rays. Among different chlorophyll mutations albino was the most frequent type. Several morphological mutants such as short-stature, early maturity, increased tillering, dark green broad leaf, narrow leaf, short exerted panicle, complete spikelet sterility, double-triple spikelet, double kernel within spikelet and lodging resistant type were appeared with variable frequencies by different doses of gamma rays in 2,07,960 individual plantlets from M2 population. Among them short-stature mutant was predominate type. A nonlinear relationship was noticed between dose of gamma rays and frequency of viable mutations. The mutagenic efficiencies were increased with increase in irradiation dose but no relationship between the doses of mutagen and mutagenic effectiveness was established. Less damages in biological traits such as lethality, injury and sterility were observed at 200 to 300 Gy dose of gamma rays. Desirable mutants were found at 200 and 300 Gy.

Risk analysis of radioecological effect of e-waste lead (Pb) content on life forms

Electronic waste (e-waste) has been proven to pollute the soil, air, and groundwater significantly. Aside from the physical effect of coming in contact with pollution, the radioecological impact of the pollution may be dangerous either directly or indirectly to persons living at the source of pollution. In this study, the lead (Pb) pollution from e-waste was used to calculate several organisms’ radioecological parameter. It is was observed that there was a moderate reduction in the number of plants with leaves (22%), a major reduction in cumulative stem growth (43% the control value), a severe increase in the number of chlorophyll mutations, severe changes in leaf colour (4.9-fold), and a major increase in mortality for all organism. It is recommended that landfill areas where e-wastes are dumped be excavated 9 m depth as a corrective measure to reduce the negative outcome on landfill workers.

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.

Mutagenic Effectiveness and Efficiency of Gamma Rays and Ethyl Methane Sulphonate on Hibiscus rosa-sinensis L. Cultivar Red Single

The present investigation was undertaken to assess the spectrum of chlorophyll mutation in Hibiscus rosa-sinensis L. Cultivar Red Single and also to study the mutagenic effectiveness and efficiency in M1V1 generation of Hibiscus rosa-sinensis L. Cultivar Red Single. Semi-hardwood cuttings of Hibiscus were treated with three doses of gamma rays viz., 25, 30 and 35 Gy and three doses of EMS viz., 0.8% (64.43 mM), 0.9% (72.48 mM, 1.0% (80.54 mM) separately. Physical mutagens created a high frequency as well as a wide spectrum of chlorophyll mutants. Totally five types of chlorophyll mutant’s viz., albino, xantha, viridis, chlorina and xantha-viridis were observed as a result of physical and chemical mutation. The mutagenic effectiveness and efficiency were calculated based on biological damage as well as chlorophyll mutation frequency on M1V1 plants. Mutagenic efficiency and effectiveness were higher in gamma radiation-induced plants particularly in a lower dose of 25 Gy. The highest mutation rate in terms of effectiveness and efficiency was observed in gamma rays than the Ethyl Methane Sulphonate treatment.

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.

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.

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.

60Co Irradiation Influences Germination and Phenotype of Three Pavonia Species

The genus Pavonia is one of the largest genera in the Malvaceae species; it is mainly distributed in South America. Three species of Pavonia were identified based on different flower colors and potential for landscape use in the southeastern United States. These species produce a large amount of seed at the end of the blooming season, which is not ideal for ornamental use. To reduce the seed set, gamma irradiation was used for mutation induction and propensity to induce compactness and sterility. A preliminary study indicated that the seed of Pavonia hastata would germinate at irradiation rates up to 2000 Gy. Seeds of three species were treated with six different dose rates ranging from 0 Gy to 1000 Gy to determine the ideal rate for Pavonia breeding and how gamma irradiation affected seed germination. M1 (the first mutant generation) P. lasiopetala and P. missionum were sown in 2018 and planted in the field at the University of Georgia Durham Horticulture Farm on 1 May 2019, as were M2 (the second mutant generation) seeds of P. hastata. Seed germination in 2019 showed no significance due to treatment but significance due to species and species by treatment interaction. Field evaluation performed in 2019 indicated that height was not influenced by irradiation for any of the three species but that the width index was. Flower diameter and leaf area of P. missionum became smaller as the irradiation rate increased, but the other two species showed no trends. Chlorophyll mutations were observed on P. hastata at the 1500 Gy level, which has attractive traits for ornamental use.

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.

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 and TMV 7. The mutagenic efficiency and effectiveness were calculated by using the chlorophyll mutants. In M1 generation, the seedling height was decreased with an increased rate of doses/concentration while lethality and pollen sterility were increased with an increased rate of doses/concentration in both the varieties on both the treatments. In the present study, the chlorophyll mutants were observed in M2. The four different chlorophyll mutants observed were albino, chlorina, xantha and striata at different crop stages of crop growth. On perusal of data, it was inferred that chlorina occurred at large followed by xantha and albino. Mutagenic effectiveness were significantly higher in gamma 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 mutagenic efficiency was increased for injury and decreased for lethality and pollen sterility with an increased rate of doses/ concentration.

Efficiency and effectiveness of physical and chemical mutagens in cowpea (Vigna ungiculata (L.)Walp)

A study was conducted in cowpea (Vigna ungiculata) varieties, VBN 3 and CO(CP) 7 to find the efficiency andeffectiveness of physical (Gamma rays and Electron beam) and chemical (EMS) mutagens. A wide range of chlorophyll mutants and viable mutants were observed in the field. Overall chlorophyll mutant and viable mutant frequency was higher in EMS treatments in both the varieties. Mutagenic efficiency and effectiveness was also found to be higher in EMS treatments followed by electron beam and gamma rays. Mutagenic effectiveness and efficiency decreased with increase in doses of all mutagenic treatments.

Induced Mutagenesis in Yellow Flowering Marigold with Colchicine in Hydrogen Peroxide

Marigold flower has many benefits in many aspects of life in Bali Island (Indonesia) including often used in religious ceremonial activities. For controlling plant pests and diseases, marigold is planted on the sidelines or on the edge of a land as an attractant crop to invite natural enemies and marigold also can produce certain substance which can reduce the incidence of nematode. In inducing mutagenesis in this research, the seeds of marigold were soaked in solution of colchicine with hydrogen peroxide as its solvent. The results of this research indicated that the treatments caused the formation of chlorophyll mutant and an increase in the length of flower diameter. Both the control and treated plant samples were attacked by leaf miner, giant land snail, virus-like disease and botrytis flower blight disease.

Study on mutagenic effectiveness and efficiency of mutagens in inducing chlorophyll mutations in m2 generation in sorghum [Sorghum bicolor (L.) Moench

An investigation was carried out to create the variability generated through induced mutation in two sorghum populations viz., 296 B (Kharif) and Parbhani Moti (Rabi). Two mutagens viz., gamma irradiation (10 kR, 20kR, 30kR and 40kR) and EMS (0.1%EMS, 0.2%EMS, 0.3%EMS and 0.3%EMS) and their combination were used M2 generation. Mutagenic sensitivity in M2 generation on the basis of reduced germination and plant survival revealed a dose dependent reaction and differential response of the populations. In general, chlorophyll mutation frequency expressed on M2 seedling basis increased linearly with doses of three the mutagens in 296 B and Parbhani Moti. The frequency was more in 296 B followed by Parbhani Moti of three mutagens. The spectrum of chlorophyll mutations comprised albina, xantha, viridis, xanthaviridis, chlorina. The most frequently occurred mutant was viridis type followed by chlorina in all the populations. The population 296 B had expressed largest frequency of chlorophyll mutants followed by Parbhani Moti.