kR Of Gamma Rays Research Articles

Development of Mungbean Genotypes for Shattering Tolerance and Correlation Analysis with Biochemical and Morphological Factors Governing Pre Harvest Sprouting

Background: Most of the mungbean genotypes are prone to shattering. The indeterminate flowering habit of this crop leads to a spread of flowering and pod maturity on a single plant over the entire reproductive phase. Consequently, pods which develop at the earliest flower may shatter prior to 100% pod maturity. Sometimes losses due to pre-harvest sprouting will be as high as 60-70%. High yielding varieties developed/identified in recent years, despite their high yield potential, could not increase/stabilize the yields of this crop due to lack of resistance to pre-harvest sprouting. Therefore, an attempt was essentially made to develop tolerant varieties to pre-harvest sprouting in the current investigation. Methods: The F2 (Healthy and well dried) seeds derived from the crosses DGGV-2 ´ Pant Moong-1 were irradiated with 60 kR gamma rays for the creation of desirable variability. The gamma rays irradiated seeds were sown in during kharif-2017 along with their respective checks to grow the F2M1 generation. Further advanced to F2M2. The individual plants were critically observed at maturity for morphological traits viz., small pod beak length and angle, thick pod wall and hard seededness that determine the tolerance to PHS. The mutant lines were compared with the parental lines viz., shattering tolerant variety Pant Moong-1 as well as susceptible variety DGGV2. The putative mutants selected and tagged in F2M2 and the seeds were harvested separately and forwarded to develop the F2M3 mutant population (1000 plants) in summer-2018. The seeds from F2M3 generation were harvested on individual plant basis and were sown. 806 progenies were sown in augmented design along with the checks in each block during kharif 2019. Thus from the population of 24812 such derived plants, genotypes with small pod beak and angle, thick pod wall, hard seededness and higher epicuticular wax and lignin content were isolated in F2M3 and F2M4. Further a total of 49 advanced breeding lines along with a known shattering susceptible check were studied for the morphometric and biochemical parameters governing the pre harvest sprouting. Result: Lower PHS was recorded in DGGV-79 (0.02%), DGGV-125 (0.02%) and DGGV 195 (0.91%). Higher phenol content was recorded in DGGV-125 (9.43 mg GA eq /g) and DGGV-79 (9.37 mg GA eq /g). Higher lignin content was recorded in DGGV-125 (6.42 mg/g) and DGGV-79 (6.10 mg GA eq /g). Further correlation analysis revealed that negative correlation of PHS was observed for epicuticular wax (r= -0.983), phenol (r= -0.892), lignin content (r= -0.981) and hard seed percentage (r= -0.942). Significant negative correlation was observed between PHS and pod wall thickness (r= -0.570). Pod beak length recorded highly significant positive correlation (r= 0.911) to PHS. Genotypes with inherent tolerance to seed shattering hold a promise to minimize yield losses due to viviparous germination.

Screening for high productive salt tolerant mutant M4 lines in chickpea(Cicer arietinum L.)

Genetic improvement through induced mutation has been very effective in improvement of crops. Seeds of three popular chickpea variety namely BGM 408, B115 and JG 315 were treated with 10,20 and 30 kR of gamma rays. Then treated seeds with their respective control(0 kR gamma rays) were sown in the field of Calcutta University experimental farm,Baruipur (with no salinity) in three consecutive years to raise M1, M2 and M3 generations respectively.Some M3 lines having higher yield potential were subjected to grow as M4 lines in salt stressed field (5-7ds m-1) of Hingalganj,South 24 Parganas. Finally, some promising salt tolerant lines with improved seed yield were selected which have a good promise for coastal saline belt after releasing as a variety.

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

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

Induction and harnessing of polygenic variability in lentil (<italic>Lens culinaris</italic> Medik.)

Three mutagenised populations each of gamma rays, sodium azide (SA) and ethyl methane sulphonate (EMS) showed increased amount of variability over control for different polygenictraits in both <italic>macrosperma</italic> (LH90-54) and <italic>microsperma</italic> (LH89-48) lentil cultivars in M<sub>2</sub> generation. Among the mutagens tested, EMS induced maximum variability for all the traits, followed by gamma rays and SA in both the cultivars. The highest frequencies of mutated [M<sub>2</sub> progenies with higher coefficient of variation (CV) than the corresponding highest CV in control for any of the traits] and promising progenies [M<sub>2</sub> mutated progenies where mean shifted in the desired direction] were induced by different mutagens in the order:EMS > gamma rays > SA in both the cultivars (LH90-54 > LH89-48). In LH 90-54, promising progenies with multiple traits were induced with the highest frequency by SA, followed by EMS and gamma rays, whereas in LH89-48, they were induced with the highest frequency by SA, followed by gamma rays and EMS. Invariably, the medium dose of mutagens (0.08%SA, 0.40% EMSand 10 kRgamma rays) induced maximum variability(CV, %), resulting in thehighest number of promising progenies for all the polygenic traits.

Induction of genetic variability and isolation of mutants in tuberose (Polianthes tuberosa L)

The effect of various mutagenic treatments on vegetative and floral characters of different cultivars of tuberose (Polianthes tuberosa L) was studied and isolation of promising mutants were done. The experimental material comprised of four tuberose varieties viz., Kalyani Single, Kalyani Double, Suvasini and Prajwal, treated with two doses each of gamma rays viz., (0.5 Kr, 1.5 Kr), X-rays (0.6 Kr, 1.2 Kr) and Ethyl Methyl Sulphonate (0.1 per cent, 0.2 per cent) along with the untreated sample (control). Results indicated that the mutagenic treatments at lower doses had significant stimulative effect on some parameters i.e., sprouting percentage, days taken to sprouting, whereas most of the parameters showed a decrease from desired levels i.e., survival rate, leaf length, number of spikes/plant & florets/spike, flowering duration and vase life. Higher doses of all mutagens were detrimental for vegetative and floral characters. Six mutants were also obtained exhibiting variation in plant height (cv. Prajwal treated with EMS (0.2%)), increase in number of petals per floret (cv. Prajwal treated with 1.2 Kr X-rays), fusion of two floret into one (cv. Suvasini and cv. Prajwal treated with EMS (0.2%)), decrease in number of whorl per floret (cv. Suvasini with 1.2 Kr gamma rays treatment) and presence of stamen in double type cultivar (cv. Suvasini with plant treated with 1.2 Kr X-rays).

Isolation of desirable induced morphological mutations in elite lines from a population ofAbelmoschus esculentus(L.) Moench by gamma rays and EMS

Induced mutation often produces abnormalities which cause morphological alterations in external form of plants including colour, shape, size, etc. In the present study, evaluation was performed during summer and kharif seasons of 2010–11 on Abelmoschus esculentus. Seeds of two elite varieties (GO-2 and GJO-3) were subjected to physical (gamma rays) and chemical (ethyl methane sulphonate; EMS) mutagenesis to find out the frequency and spectrum of induced desirable morphological mutations. In M2 generation, 12 different morphological mutations were induced in both the varieties. It was found that the spectrum of these mutations and their frequency varied with the type and dose of mutagens and the genotype used. Gamma radiations induced more number of morphological mutants as compared to EMS treatments in both the varieties. The highest mutation rate (11.19%) was detected in 40 kR gamma rays treatment followed by 0.25% EMS treatment in GO-2. In general, gamma irradiation treatments seemed to be superior in producing greater frequencies over all doses for both the varieties GO-2 (19.17%) and GJO-3 (16.33%).

Effect of Different Dose of Gamma Rays on Two Varieties of Linseed Crop (Linum usitatissimumL.)

Two diverse and improved varieties of, linseed crops namely T-397 and Shekhar were exposed to different doses of gamma rays viz. 40, 50 and 60 kR a Co60 source at the National Botanical Research Institute, Lucknow. Yield in oilseed is a complex trait in which plant height, number of branches per plant, number of pods per plant, grain yield per plant and seed weight constitued to be the major yield components. Addition to this types of mutagen and different dose of mutagens are also important in relation to creation of variability. The present findings on induced polygenic variability in two varieties of linseed (T-397 and Shekhar) clearly exhibited the significant differences between the mean values recorded for different populations of mutagenic treatments and the control for all the chraracters studied. The behaviour of varieties was observed to be changed for survival of plants scored at maturity where T-397 had higher percentage of plant survival as compared to Shekhar. The means of treated populations shifted in negative directions as compared to that of control. Based on Lethal Dose50 (LD50) as to minimize DNA damage and reduce undesirable mutations, radiation doses which lie between 40 and 60 kR of gamma-rays can be considered suitable for induction of mutation in linseed varieties. It is important to note that the doses or concentrations of mutagens selected had negative effects on mean but showed positive effects on variability for grain yield per plant.

FORTY YEARS OF PAPAYA RESEARCH AT PUSA, BIHAR, INDIA

Systematic research work on was started during 1966-67 at Indian Agricultural Research Institute Regional Station, Pusa, Bihar, India with an objective to breed the varieties of uniform, high yielding with better quality for wider adaptability. Four varieties viz., Pusa Delicious, Pusa Majesty (Gynodioecious), Pusa Giant and Pusa Dwarf (Dioecious) were developed through continuous sibmating and selection by conventional breeding. Pusa Nanha (Mutant dwarf) was developed through mutation breeding by treating the seeds of strain Pusa 1-15 with 15 Kr gamma rays. Comprehensive studies on sex inheritance in inter and intra-varietal crosses of were attempted and a significant deviation of male and hermaphrodite from the expected ratio was observed. Genetic constitution of sex reversing male in was established. Standardized the production technology of in respect to planting density, time, nutrition and based cropping system under North Bihar conditions. A marked reduction in viral infection was found by transplanting the in month of October with heavy manurial doses. A new fungal disease bud and fruit stalk rot of papaya was discovered and standardized its control measure. Seed production of under controlled pollination and isolation were done and found that seed produced under controlled pollination maintains maximum varietal purity with very high cost and less seed where as seed produced in isolation is more with low cost.

Effect of Gamma Rays and EMS on Two Varieties of Soybean

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

DEENANATH CO-1: A NEW ANNUAL FODDER GRASS FOR TAMIL NADU

In order to develop an annual fodder grass variety to fit into short gaps in the crop rotation, the Pusa-3 Deenanath grass was irradiated with 30 KR gamma rays and from the later generations, a high yielding mutant TNDN-1 was isolated. The culture was tested in different trials and it recorded an average green fodder yield of 44.32 t/ha under irrigated conditions and 23.41 tha under rainfed situations. It can be cut at 60-65 days and it has high crude protein (9.06%), crude fat (2.55%) and low crude fibre (28.95% ). The variety was released as Co-1 for general cultivation in Tamil Nadu.

In Vitro Culture of Hybrid Indica Rice Combined with Mutagenesis

AbstractThe mutagenic effects of gamma radiation and sodium azide (SA) immersion of explants on culturability and frequency of somaclonal variation in indica rice were investigated. The results showed that young inflorescence and mature embryo were satisfactory explants both for in vitro culture and for mutagenesis. 1 kR gamma rays applied to immature embryos and exposure of calli derived from mature seeds at the dose range of 250—500 R led to a higher rate of callusing and plantlet regeneration, 0.5—1 kR would be the appropriate exposure for young inflorescence to produce a better culture response and higher variability, and 2.5—5.0 kR the optimal dose range for mature embryos. Immersion of mature seed in 2—4 mM sodium azide solution is a concentration level to induce these effects in indica rice. Application of optimal gamma exposure and chemical mutagen to rice explants enhanced the somaclonal variation frequency and provided a large number of variants useful for rice breeding.

RADIATION INDUCED MUTATIONS IN CHINESE POTATO

Effects and efficiency of gamma ray treatments on induced variability for yield contributing traits were studied in Chinese potato (Coleus parviflorus Benth), in which lack of morphological variability has been observed in the germplasm collection made so far. Underground tubers weighing 1.5 g/uber of accession number CP 11 were treatment with 1 KR, 2 KR, 3 kr and 4 kR gamma rays. Besides tubers weighing 3 g and 6g/tuber were also treated with 3 KR gamma rays. The study indicated that the growth reduction in MVI generation was linear, with increasing dose of gamma rays and the 50% growth reduction (LD50) dose observed was with 3 kR gamma ray treatment. From the study more than 50 different morphological solid mutants were obtained representing variability for plant structure (new ideotype), leaf size and shape, flowering and tuber characters.

INDUCED MUTAGENIC EFFECTS OF QUANTITATIVE CHARACTERS IN RICE (Oryza sativa L).

Seeds of the rice variety Co 37 were treated with gamma rays, Ethyl methane Sulphonate (EMS) and their combination treatments. The mean, range, variance and co-efficient variation were estimated in the M2 generation for five traits. In general, the mean values of the most of treatments in M2 did not substantially deviate from the control, but variability had increased in mutagenic treated populations. Mean values for productive tillers and yield per plant had shifted in a positive direction with 10 and 20 KR gamma rays than other treatments including control. Selection may be effective for productive tillers and vield per plant at lower dose of gamma rays.

Effect of gamma-irradiation on germination and leakage of electrolytes from peanut ( Arachis hipogaea L.) seeds

Apical and basal seeds of Spanish peanut (cv. “Valenciana”) were irradiated with 0, 10, 20 and 40 kR gamma-rays, and germinated at 25 ± 1°C. The effect of irradiation on conduction of electrical current (EC in μA) of electrolytes leaked from individualized seed was monitored by an Automatic Seed Analyzer Computer (ASAC-1000), and the percentages of normal, abnormal and dead seeds during the 12-day germination period were recorded. Differences in weight, length, volume, and surface were observed among the two types of seeds. A probit analysis of the percentage of normal seedlings by germination according to ISTA guidelines indicated that the basal seeds, smaller in weight and volume, had a radio-resistance 2.38 times greater than that of the apical seeds.

Induced polygenic variation and genetic architecture in Indian mustard

The F1 seed obtained from an eight-parent diallel (excluding reciprocals) in Indian mustard was treated with 100 Kr of gamma rays, grown and selfed to obtain F2M2. The mean was decreased in the majority of the crosses in an irradiated set whereas the coefficient of variation increased. Combining ability analysis revealed the change in relative ranking of the parents and crosses and suggested the genotype-specific responses to irradiations. Components of combining ability and heterosis were also changed considerably. In some cases irradiation resulted into an increase in additive genetic variance.

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.

The protective effect of irradiated metacercariae of Fasciola gigantica against homologous challenge in sheep.

Five lambs were each sensitized with 400 metacercariae of Fasciola gigantica irradiated at 3 kr gamma rays. Eight weeks later, they were each challenged together with 5 controls with 500 non-irradiated metacercariae. Eight weeks later, all of the animals were necropsied and the worm burdens determined. The lambs which received the sensitizing infections had 80% less worms than the controls. The sensitized lambs also showed less hepatic damage compared with the controls as indicated by lower levels of the serum enzyme glutamate dehydrogenase. The blood indices showed insignificant reductions in the sensitized lambs whereas marked reductions were found in the erythrocytes, packed cell volume and haemoglobin values of the challenge controls. Bilirubinaemia was also evident in this latter group.

FODDER COWPEA CO. 5 FOR PROTEIN RICH FODDER

Mutation breeding undertaken to evolve a high yielding, short duration fodder cowpea variety resulted in the identification of a mutant FCP 2 which was isolated in M5 generation of Co 1 cowpea seeds irriadiated with 30 Kr gamma rays. The mutant has a green fodder, yield potential of 18,16 t/ha in 50 to 55 days which was 32,74% higher than that of Co 1. It is high in crude Protein content and dry matter digestibility. It was released as Co 5 fodder cowpea in 1986.

Genetic Analyses of Nonfluorescent Root Mutants Induced by Mutagenesis in Soybean1

Nonfluorescent root mutants in soybean [Glycine max (L.) Merr.] are useful as markers in genetic studies and in tissue culture research. Our objective was to obtain mutagen‐induced nonfluorescent root mutants and to conduct genetic studies with them. Thirteen nonfluorescent mutants were detected among 154 016 seedlings derived from soybean lines treated with six mutagens. One of these mutants, derived from ‘Williams’ treated with 20 kR gamma rays, did not correspond to any of the known (standard) nonfluorescent spontaneous mutants. This is the first mutagen‐induced nonfluorescent root mutant in soybean. It was assigned Genetic Type Collection no. T285 and the gene symbol fr5 fr5. The fr5 allele was not located on trisomics A, B, or C and was not linked to five chlorophyll‐deficient mutants (y9, y11, y12, y13, and y20‐k2) or flower color mutant w1. The remaining nonfluorescent root mutants were at the same loci as known spontaneous mutants; i.e., four had the fr1 allele, five had the fr2 allele, and three had the fr4 allele.

Radiation induced pollen sterility and enhanced outcrossing in groundnut ( Arachis hypogaea L.)

Seeds of six groundnut cultivars with distinguishable morphological features were irradiated with 5, 10, 15 and 20 kR gamma rays and grown surrounded by a pollen parent. The effect of irradiation on pollen sterility and other quantitative characters was studied in M 1. Pollen sterility increased almost linearly with increase in dose in each cultivar. There was significant variety × dose interaction. The correlation between inherent pollen sterility (measured in control) and percent increase in sterility was negative. The induced variation was significant only for five quantitative characters. Fifteen kR was the most effective dose for inducing a high level of pollen sterility without causing significant change in other characters. The correlation between pollen sterility and cross-pollination % was positive and significant implying that induced pollen sterility would enhance cross-pollination.