Inducing Chlorophyll Mutations Research Articles

Induced chlorophyll mutations in Gloriosa superba

The present experiment was carried out to study the spectrum of chlorophyll mutations, mutagenic effectiveness and efficiency in Gloriosa superba seeds using both chemical and physical mutagens. Self pollinated seeds of glory lily ecotype Gs-15 were treated with different doses of gamma rays viz., 10, 20, 30 and 40 (Gy), EMS viz., 10, 20, 30 and 40 mM and DES 15, 20, 25 and 30 mM. Both physical and chemical mutagens had significantly contributed to the production of the spectrum of chlorophyll mutants with higher mutagenic effectiveness and efficiency. The treatment of mutagens resulted in the production of four types of chlorophyll mutants viz., albina, xantha, chlorina and viridis. The mutagenic effectiveness and efficiency were calculated based on biological damage as well as chlorophyll mutation frequency on M1 plants. The results indicated that the mutagenic efficiency was the highest, at lower and intermediate concentrations of mutagens. The frequency of xantha (8.36) mutants were the highest followed by viridis (7.01) and other types were observed in all the treatments. Among different treatments, gamma rays were effective than the other two chemical mutagens in inducing different chlorophyll mutations. A comparatively lesser number of albina (2.13) mutants were observed with respect to all the mutagens studied. The higher frequency of mutations was observed in gamma irradiated seedlings (28.28) as compared to EMS (17.57) and DES (11.96). Likewise, the mutagenic effectiveness was at an increased score (81.10%) with 10 Gy gamma irradiation treatment. With regard to the EMS, based on lethality, increased mutagenic efficiency (27.37%) was observed at 20 mM concentration. Conversely, lower doses of physical mutagen (gamma radiation) induced a higher mutagenic rate, while EMS registered a lower score of mutations. Key words: Glory lily, seeds, EMS, DES, gamma rays, chlorophyll mutants, mutagenic effectiveness and efficiency

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 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.

Comparative effectiveness and efficiency of gamma rays, ethyl methane sulfonate and maleic hydrazide in induction of chlorophyll mutations in black gram (Vigna mungo (L.) Hepper)

The present investigation was taken up to study the effectiveness and efficiency of gamma rays, ethyl methane sulfonate and maleic hydrazide in induction of chlorophyll mutations in two blackgram varieties viz., LBG 752 and TBG 104. The seeds were treated with different doses/concentrations of gamma rays (200 Gy, 300 Gy, 400 Gy, 500 Gy and 600 Gy), EMS (Ethyl methane sulfonate) (0.2%, 0.3%, 0.4%, 0.5% and 0.6%) and MH (Maleic Hydrazide) (0.01%, 0.02% and 0.03%). A wide spectrum of chlorophyll mutations viz., albina, xantha and chlorina was observed in M2 generation and chlorina was the most frequent chlorophyll mutant in all the mutagen treated populations of both the varieties. There was a dose dependent increase in the frequency of chlorophyll mutations. This study showed that the effectiveness and efficiency of chlorophyll mutations declined considerably with the increase in dose of the mutagens. MH treatments were more effective followed by EMS and gamma rays treatments in both the varieties. With respect to efficiency, the gamma rays were more efficient followed by EMS and MH treatments in both the varieties for inducing chlorophyll mutations on the basis of injury, lethality and sterility except based on lethality in TBG 104, where MH treatments showed highest value followed by gamma rays and EMS treatments.

Study of chlorophyll deficit types through induced mutagenesis in blackgram (Vigna mungo L. Hepper)

The investigation was carried out to study the phenotypic reaction of seeds of CO 6 blackgram variety exposed to Gamma rays doses at 200 Gy, 300 Gy, 400 Gy and combination treatments with 200 Gy + 20 mM EMS, 200 Gy + 30 mM EMS, 300 Gy + 20 mM EMS, 300 Gy + 30 mM EMS, 400 Gy + 20 mM EMS, 400 Gy +30 mM EMS. It was observed that different mutation frequencies and span of mutation spectra were induced under the action of different concentrations of the applied mutagens in the M2 generation of blackgram. Five different types of chlorophyll mutants namely albino, xantha, chlorina, viridis, and maculata type were observed in the M2 populations and chlorophyll mutation frequency was calculated on a plant population basis. In Gamma treated population, the frequency of xantha mutants was high followed by chlorina whereas in combination treatments of Gamma ray + EMS, the highest frequency was observed in chlorina followed by xanthan mutants. Maculata type of chlorophyll mutant was observed in the treatment 200 Gy + 20 mM EMS. The combination treatments of Gamma ray + EMS were found to be more efficient than gamma rays alone in inducing chlorophyll mutations. The frequency of chlorophyll mutations (2.51%) was high in the combination treatment 400 Gy+ 30 mM EMS.

Induced mutations in soybean (Glycine max L.)

Frequency of chlorophyll and viable mutations have been studied following seed treatment of soybean cv.PK 1029 with gamma rays, EMS and their combinations at varying doses. Mutation rate indicated that EMS @ 0.10 % was most potent in inducing the chlorophyll mutations whereas 20 kR was most efficient in inducing the viable mutations. The frequency and spectrum of the induced chlorophyll mutations was in the order of xantha, albino, chlorina and viridis. The frequency and spectrum of the induced viable mutations was in the order of plant type, leaf type, seed type and pod type. Combination of gamma rays and EMS treatment showed high lethality in inducing both chlorophyll and viable mutations.

Frequency and spectrum of chlorophyll mutants induced by gamma rays and EMS in two chickpea varieties (Variety- Vijay and PKV-2)

Chickpea is one of the most important leguminous food grain grown worldwide. Mutagenesis could be used as a classical way to increase genetic variability in chickpea considering its narrowing genetic base. Present study was an attempt to analyze the frequency and spectrum of chlorophyll mutations induced by gamma rays (300, 400 and 500 Grey) and ethyl methanesulphonate (0.2%, 0.3% and 0.4%) in M 2 generation of varieties of chickpea (Var-Vijay and PKV-2). Broad spectrum chlorophyll mutants were isolated from M 2 generation. The relative frequency of these mutants in both varieties was observed in order of Tigrina > Viridis > Chlorina > Xantha and Albina. The total chlorophyll mutation frequency increased with increase of dose upto certain limit and then started declining. However, the effectiveness of EMS was found to be more prominent than gamma rays especially in inducing chlorophyll mutations in Chickpea.

Induced chlorophyll mutations in bell pepper (Capsicum annuum L. var. grossum)

An investigation entitled “Induced chlorophyll mutations in bell pepper (Capsicum annuum L. var. grossum)” was conducted during kharif (summer-rainy season) 2012 and 2013 at Experimental farm of the Department of Vegetable Science and Floriculture, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur, H.P., India. Healthy seeds of California Wonder of bell pepper were exposed to physical mutagen Gamma rays using 60CO as a source of radiation at Mutation Breeding Centre, Department of Biotechnology, BARC Trombay, Mumbai and chemical mutagen EMS (Ethyl Methane Sulphonate) to obtain the spectrum and frequency of chlorophyll mutations in M2 generation. The M1 generation was produced from these mutagen treated seeds. Several unique and interesting chlorophyll and viable mutants were obtained in M2 generation. In M2 generation, gamma rays induced higher proportion of chlorophyll mutants then EMS. A progressive increase in mutation frequency of chlorophyll mutations was observed with increasing doses/concentrations. Four different types of chlorophyll mutants namely xantha, yellow xantha, chlorina and viridis were induced. Out of these mutants, chlorina and viridis were most frequent and were produced even in lower doses/concentrations while yellow xantha was least frequent and produced only in higher doses. The highest frequency of chlorophyll mutations (18.8 %) was reported in the 22 kR of gamma dose, while the lowest (0.80 %) frequency of chlorophyll mutations was found in the treatment of 1.0 % EMS. There was a dose dependent increase in the spectrum and frequency of chlorophyll mutations. These chlorophyll mutants induced by gamma radiation and EMS could be used in mutation breeding programme for inducing viable mutations for improvement of bell pepper varieties.

Spectrum and frequency of mutations induced by gamma rays and EMS in okra [Abelmoschus esculentus (L.) Moench

The seeds of okra variety P-8 were treated with different concentrations of gamma rays (65kR, 75kR and 85kR), EMS (1.2%, 1.4% and 1.6%) and their combinations to obtain the phenotypic response during M2 generation. Different mutation frequencies and width of mutation spectra were induced under the action of different concentrations of the applied mutagens. A progressive increase in mutation frequency of chlorophyll mutations was observed with increasing doses. Four different types of chlorophyll mutants, such as albino, xantha, viridis and chlorina were induced with effect of mutagens on plant population. The spectrum and frequency of chlorina mutants were highest followed by xantha, viridis and albino in all the treatments. The sole treatments of mutagens were found to be more efficient than combinations in inducing chlorophyll mutations. The highest frequency of chlorophyll mutations (0.044%) was reported in the 75kR+1.2% EMS. Based on the chlorophyll mutation frequency, it was found that EMS was most effective followed by gamma rays and combination of treatments.

Induced mutagenesis in Chickpea (Cicer arietinum (L.) with special reference to the frequency and spectrum of chlorophyll mutations

A relative study of frequency and spectrum of chlorophyll mutations induced by mutagens in M2 generation was made with chickpea (Cicer arietinum (L). Variety ‘CO-4’. The treatments include different doses/concentrations of Gamma rays (20, 30, 40, 50 and 60kR) and Ethyl Methane Sulphonate (10, 20, 30, 40 and 50 mM). From the study, the overall frequencies and spectrum of five types of induced chlorophyll mutants Viridis (0.55), Xantha (0.46), Chlorina (0.45), Albina (0.43) and Tigrina (0.35) were observed. The frequency of chlorophyll mutation was increased with increasing concentrations up to a level, beyond it declined in both the mutagens. And the chlorophyll frequency was found in the order of viridis > xantha >chlorina> Albina >tigrina. The chemical mutagen, EMS was found to be more effective in inducing chlorophyll mutations than gamma rays in Chick pea.

Frequency and spectrum of chlorophyll mutations and induced variabilityin ricebean (Vigna umbellata Thunb, Ohwi and Ohashi)

A comparative study of frequency and spectrum of chlorophyll mutations induced by physical (gamma rays) and chemical mutagens (EMS) in relation to the effect of mutations in M1 plant, induction of mutants in M2 and variability studies in M3 generation was made in two ricebean (Vigna umbellata Thunb, Ohwi and Ohashi) varieties; one local (Totru Local) and one widely cultivated one (BRS-1) during 2005-2008. The treatments included three doses each of gamma rays (30, 40 and 50 kR) and EMS (0.50, 0.60 and 0.70%). Both gamma rays and EMS proved to be hazardous for germination and plant survival at higher dose and the comparative reduction in these characters was higher under EMS treatments than gamma rays. The frequencies and spectrum of five different kind of induced chlorophyll mutations was in the order; viridis > xantha = albina > chlorina > albo-viridis in BRS-1 and viridis > xantha > albina > chlorina = albo-viridis in Totru Local. EMS was found to be more effective in inducing maximum frequencies of chlorophyll mutants than gamma rays. Highest frequency of chlorophyll mutants were found under O.50% EMS in BRS-1 and 0.70% EMS in Totru Local. Genotypic differences were seen as highest frequency of mutations was observed in Totru Local which was more sensitive to mutagenic treatments than BRS-1. The coefficients of variation for all quantitative characters studied in M3 generation were of higher magnitude compared to control in both the cultivars. The lower doses (30kR in gamma rays and 0.50% in EMS) were found to be the most important doses for inducing desirable variability in ricebean and three traits i.e. pods per cluster, seeds per pod and pod length showed high heritability coupled with high genetic advance in both BRS-1 and Totru Local indicating that breeding for these traits can be achieved by phenotypic selection.

Induced chlorophyll mutations. I. Mutagenic effectiveness and efficiency of EMS, HZ and SA in mungbean

A systematic and comparative study on the frequency and spectrum of chlorophyll mutations induced by ethylmethane sulphonate (EMS) — an alkylating agent, hydrazine hydrate (HZ) — a base analogue and sodium azide (SA) — a respiratory inhibitor, was carried out in two mungbean varieties, namely, PDM-11 and NM-1. Awide spectrum of chlorophyll mutants was obtained in the M2 generation. All these chlorophyll-deficient mutants were lethal except maculata, viridis and virescent. Chlorina followed by xantha types were predominant in both the varieties. EMS treatments induced the highest frequency of chlorophyll mutations followed by HZ and SA. The frequency of chlorophyll mutations was dose-dependent and increased with the mutagen concentration. Based on effectiveness in both varieties, the order of mutagens was HZ > SA > EMS. Two criteria viz., pollen sterility (Mp/S) and seedling injury (Mp/I) were taken into consideration to determine the efficiency of the mutagens. EMS was found to be the most efficient mutagen followed by HZ and SA. Moderate concentrations of the mutagens were the most effective and efficient in inducing mutations.

Induced chlorophyll mutations in Delphinium malabaricum (Huth) Munz.

Induced chlorophyll mutations in Delphinium malabaricum (Huth) Munz.

Studies on induction of chlorophyll mutations in soybean, Glycine max (L.) Merrill

The phenotypic response of two soybean cultivars to a chemical mutagen (ethyl methane sulphonate, EMS), physical mutagen (gamma rays) and their combinations were studied in M1 and M2 generations and the frequency and spectrum of chlorophyll mutations were worked out. Combined treatment was found to be more effective in inducing chlorophyll mutations compared to individual treatments of gamma rays and EMS in both the cultivars. As far as the spectrum of chlorophyll mutations is concerned, a wider spectrum in both the cultivars was observed in 45 kR + 0.2% EMS combined treatment.

Induced mutations in Triticum aegilopoides, Aegilops ventricosa and their synthetic allopolyploid

Seeds of the diploid, Triticum aegilopoides (2n = 2x= 14 = AA), the tetraploid, Aegilops ventricosa (2n = 4x = 28 = MvMvDD) and their synthetic hexaploid (2n = 6x = 42 = AADD MvMv) were treated with gamma rays (16 kR) and with 1% aqueous solution of ethyl methanesulphonate (EMS) for 1 1/2 hours and 3 hours. In the diploid no mutation was observed probably owing to the low number of M2 seedlings derived from gamma rays treatment. The gamma rays seemed to produce more mutations than EMS in the tetraploid. In the hexaploid, the gamma rays and EMS seemed equally effective in producing mutations. At all levels of ploidy, EMS treatment for 3 hours induced more mutations than the EMS treatment for 1 1/2 hours. The present results confirm earlier results obtained from studies of induced mutations in natural polyploids and their putative parents. The induced chlorophyll mutations decreased with increasing number of homoeologous genomes. The buffering of the genic system behind the chlorophyll apparatus in the synthetic amphiploid was comparable with the situation in natural amphiploids. The synthetic amphiploid provides an additional example of homoeoallelism. The evolutionary significance and the possible roles of induced recessive mutations in improving the wild characters of Triticum aegilopoides, Aegilops ventricosa and of their synthetic amphiploid are discussed with reference to the incorporation of useful genetic variations into the cultivated wheats.

Gamma-Ray Radiation and Sodium Azide (NaN3) Mutagenic Efficiency in Rice

Rice (Oriza sativa L.) cultivar IAC-1246 seeds were treated with 10, 15, 20 and 30 Krads of gamma-rays and sodium azide (SA) concentrations of 0.5, 1.0 and 5.0 mM to study their efficiency in inducing chlorophyll mutations. Combined treatments incremented the damages when compared to single treatments, especially for seedling height and M 1 panicles fertility. Treatments with SA showed a higher frequency of chlorophyll mutations than the gamma-ray treatments, both in single and combined treatments. The gamma-ray spectrum was different for the various types of mutations, whether in individual or combined treatments. The SA efficiency was higher than that of gamma - rays at 1.0 and 5.0 mM concentrations and lower at 0.5 mM. On average, the additive effect of the mutagenic combinations was more evident than the frequencies of the mutations.

Relative effectiveness and efficiency of single and combination treatments using gamma rays and sodium azide in inducing chlorophyll mutations in rice.

Seeds of rice cultivars Jaya, IET 5656 and Fujiminori were presoaked for 24 hours and then (a) irradiated with 4, 6, 8, 10 and 12 KR gamma rays, (b) treated with 0.001, 0.002, 0.004 and 0.005 molar solutions of sodium azide at pH 3 for 4 hours, or (c) subjected to combinations of the above with the view to study their relative effectiveness and efficiency in inducing chlorophyll mutations in rice. In all three varieties azide treated entries showed a higher frequency of chlorophyll mutants than did the gamma ray treated entries, under both single and combination treatments. In the variety Jaya sodium azide treatments showed a higher efficiency and effectiveness than gamma rays and combination treatments and they were more or less similar in both single and combination treatments in the other two varieties. The indica cultivars Jaya and IET 5656 were more sensitive than the japonica cultivar, Fujiminori to producing chlorophyll mutations. Sodium azide appears to be more efficient than gamma rays alone or in combination.

Azide mutagenesis in rice

Seeds of rice cultivars viz Jaya, IET 5656 and Fujiminori presoaked for 24 h were treated with 0·001, 0·002, 0·004 and 0·005 molar concentrations of sodium azide at pH 3 for 4 h with a view to investigate its mutagenic action in rice. The percentage of germination, survival, seedling height and leaf number decreased in the treated population with a few exceptions. Cytologically abnormal plants were not detected in any of the treated population. Plant height, panicle branches, seed set and panicle grain weight decreased in the azide treated population whereas tiller number increased in Jaya and Fujiminori cultivars. The frequency of chlorophyll mutants induced was more in Jaya less in IET 5656 and the least in Fujiminori 0·005 molar concentration was found to be the most effective for inducing chlorophyll mutations in IET 5656 and Fujiminori. The same concentration induced more morphological mutants in all the 3 cultivars. Morphological and physiological mutants isolated include the tall, semidwarf, dwarf, early and late flowering mutants, protein rich mutants, grain shape mutants and many others. Varietal differences are indicated in the induction of seedling injury and of chlorophyll and morphological mutants produced.

Mutagenic response of rhodes grass (Chloris gayana Kunth.) to gamma rays. II. Studies on second (M2) generation parameters

The effect of gamma rays on parameters such as chlorophyll mutation frequency and spectrum, mutagenic effectiveness and efficiency and viable mutation frequency and spectrum were studied in M2 generation of Rhodes grass employing nine doses of gamma rays. The chlorophyll mutation frequency increased in a linear fashion at low and medium doses and was erratic at higher doses. The chlorophyll mutant spectrum ineluded albina, xantha, chlorina, viridis, tigrina, striata, albo-xantha and albo-viridis. The frequency of these mutants varied with treatments. A dose rate of 60 krad was found to be effective as well as efficient both on M1 and M2 plant basis in inducing chlorophyll mutations. The highest frequency of viable mutations was found in 50 krad treatment. Viable mutants found were: nodal variant, peduncle variant, lax ears, coxcomb ears, earhead proliferation, level of fingers, incurved fingers, gappy ears, apical sterility, partial sterility and high sterility.

Influence of respiratory inhibitors on ethyl methanesulphonate induced mutagenic effects in Hordeum vulgare.

With an object of modifying the treatment conditions based on the concept of selection sieves, which may result in the higher mutagenic effectiveness and efficiency, barley seeds were treated with ethyl methanesulphonate (EMS) in various com-bination with non-toxic concentration of sodium azide (NaN3) and sodium arsenite (NaAsO2) as chemical modifiers. Treatments were carried out with dry, watersoaked and dried back seeds. Effects of these chemical modifiers in respect of pre-, post- and during treatment of EMS were also investigated considering the parameters, seedling injury, chromosomal aberrations, chlorophyll chimeras and sterility in M1 and chlorophyll deficient mutations as an index in M2. NaAsO2 did not induce chlorophyll mutations. However, NaN3 even in aqueous non-buffered solution induced chlorophyll mutations. As regards to their modifying action, although sodium azide and sodium arsenite both were used as common respiratory inhibitors, NaN3 was found to be most effective as a pre-treatment modifier in case of dry and dry-back seed treatments. Treatment of NaN3 soaked dried seeds with EMS synergistically increased the mutation frequencies but in general, combination treatments of NaN3 and EMS with soaked seeds were found to be highly deleterious. NaAsO2 has not been fonud to be effective as a pre-treatment modifier. It was very effective in during and post- EMS treatment combinations.