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Bioremediation, Biodiversity and Bioavailability

Volume 6 Special Issue 1 2012
Induced Mutagenesis in Crop Plants

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ISBN 978-4-903313-96-2

How to reference: Ranalli P (2012) The Role of Induced Plant Mutations in the Present Era. In: Kozgar MI, Khan S (Eds) Induced Mutagenesis in Crop Plants. Bioremediation, Biodiversity and Bioavailability 6 (Special Issue 1), 1-5


Guest Editors

Mohammad Imran Kozgar, Samiullah Khan

Aligarh Muslim University, India

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www.amu.ac.in

 


Issue infomation

CONTENTS AND ABSTRACTS

Paolo Ranalli (Italy) The Role of Induced Plant Mutations in the Present Era (pp 1-5)

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ABSTRACT

Invited Mini-Review: With the imminent threats posed by global climate change to crop production and the ever increasing and more sophisticated demands of agricultural products, crop improvement efforts have to be more powerful and precise in developing new crop varieties. Breeders therefore require tools that permit achieving subtle changes to the genetic make-up of otherwise superior crop varieties e.g. high yielding but lacking in specific quality traits and yet leaving the genome largely intact in order not to disturb already stacked alleles of genes. The availability of genomics information in the public domain coupled with recent advances in molecular and cellular biology techniques have paved the way for transforming old mutation techniques into state of the art technology for both crop improvement and basic genomics research. Cellular biology techniques will address the bottlenecks imposed by the need to rapidly generate large mutant populations of suitable genetic backgrounds (homozygous for the mutation events, and devoid of chimeras). New, space-age technologies are being developed for mutation induction. Thus, mutation assisted plant breeding will play a crucial role in the generation of ‘designer crop varieties’ to address the uncertainties of global climate variability and change, and the challenges of global food insecurity.

 

Suprasanna Penna, Sonawane Balasaheb Vitthal, Patade Vikas Yadav (India) In Vitro Mutagenesis and Selection in Plant Tissue Cultures and their Prospects for Crop Improvement (pp 6-14)

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Invited Review: Mutation induction has become a powerful tool for developing new and novel plant germplasm. Methods such as gammaray irradiation, ion beams and chemical mutagens have been applied to induce mutations. Since availability of a large number of mutagenized populations for screening and methods of selection are still a hindrance with conventional mutagenesis, in vitro mutagenesis of cultured explants, cells and tissue cultures represent a feasible method for induction of genetic variability. Selection at the cellular level has been practised for desirable traits and success has been achieved in several crop plants. This article outlines the different aspects of in vitro mutagenesis and selection for varied applications in crop improvement.

 

Subodh K. Datta (India) Success Story of Induced Mutagenesis for Development of New Ornamental Varieties (pp 15-26)

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ABSTRACT

Invited Review: Induced mutagenesis is well recognized as one of the most important technology for the development of new varieties through genetic manipulations. Mutation techniques, using physical and chemical mutagens, have successfully produced quite a large number of new promising varieties in different ornamental plants. This technique has been most successful in ornamental plants due to some additional advantages. Changes in any phenotypic characteristics like colour, shape or size of flower and chlorophyll variegation in leaves can be easily detected. Heterozygous nature of many of the cultivars offers high mutation frequency. The main advantage of mutation induction in vegetative propagated crops is the ability to change one or a few characters of an otherwise outstanding cultivar without altering the remaining and often unique part of the genotype. Voluminous literature for successful application of classical induced mutagenesis have been generated on radio-sensitivity, selection of materials, methods of exposure to gamma rays, suitable dose, detection of mutations, mutation frequency and spectrum, isolation of mutants and commercial exploitation of mutants. Different treatment methodology like recurrent irradiation, combined treatment, split dose, colchicine treatment, ion beam technology, space breeding, TILLING, EMAIL, etc., have been precisely determined for successful development of new varieties. The main bottlenecks in mutation breeding of vegetatively propagated plant are formation of chimeras. Therefore, attempts were made to find out the ways to overcome this situation. Management of chimera and in vitro technique have opened a new way for isolating new flower colour/shape ornamental cultivars through retrieval of mutated cells. Step wise advancement/refinement of practical approaches for application of classical induced mutagenesis and recent techniques for improvement of ornamental crops have been highlighted.

 

Sanjay G. Auti (India) Induced Morphological and Quantitative Mutations in Mungbean (pp 27-39)

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ABSTRACT

Invited Review: Pulses occupy an important position in world agriculture because of their high protein content, several essential amino acids and their capacity for fixing atmospheric nitrogen. Mungbean (Vigna radiata (L.) Wilczek) is one of the most important pulse crops due to its nutritive value and property of maintaining and restoring soil fertility through biological nitrogen fixation. Genetic variability is one of the prerequisites for crop improvement. Lack of required amount of variability, limits the scope for the selection of better genotypes in mungbean. Artificially induced mutations are the best way to enlarge genetic variability considerably within a short time. Frequency of the natural mutation is very low and hence artificial mutations are induced and genetic variability is best enhanced with the application of mutagens. Based on above fact, the development of high yielding varieties in mungbean is possible by the exploitation of larger range of genetic variability. Mungbean have been traditionally grown in marginal land of lower productivity with the application of little inputs. The selection pressure in case of these crops has been concerned more with adaptation to stress conditions than for yield. Therefore the genetic improvement of such crops, for higher yield requires their genetic reconstitution to evolve different plant types. Induced mutations can help to regenerate and restore the variability, which has been lost in the process of adaptation to various stresses or adaptations during the course of evolution. Thus mutation breeding or induced mutation is having great potential for the improvement of traditional agricultural crops like mungbean.

 

Rodrigo R. Latado, Augusto Tulmann Neto, Antonio Figueira (Brazil) In Vivo and in Vitro Mutation Breeding of Citrus (pp 40-45)

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Invited Mini-Review: Spontaneous mutations are important for the development of new citrus varieties, but they appear at very low frequency in nature. On the other hand, induced mutagenesis using radiation or chemical mutagens can increase many folds the rate of mutation resulting in increased genetic variability to be used for selection. But, up to now, few mutants induced were officially released for cultivation, possibly because citrus plants are vegetatively propagated, with a long reproductive cycle and require much space to be cultivated. Physical mutagens (gamma-rays, X-rays or thermal neutrons) were the most commonly used in mutation induction, usually employing buds or seeds as starting materials. Chemical mutagens were less used, possibly due to the difficulties associated with tissue penetrability and that the target propagules are not seeds. Up to now, most projects using induced mutagenesis in citrus aimed at developing new cultivars with emphasis on obtaining seedless or fewer seeds per fruit; resistance to diseases; improved fruit color (skin and pulp); fruits with alteration in harvest time; and plants with height reduction. Induced mutants of citrus have been described in several countries. The development of new areas of biology (e.g functional genomics and bioinformatics) and new high throughput related technologies, such as high performance sequencing, TILLING (targeting induced local lesions in genomes), microarray, real-time PCR and others, associated with induced mutagenesis, can help in gene discovery programs to elucidate function and mechanisms of gene action.

 

Digambar Dadaji Ahire (India) Induced Mutations for Elevated Oleic Acid and Reduced Linolenic Acid Content in Soybean Seeds (pp 46-52)

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ABSTRACT

Invited Mini-Review: The high linolenic acid content (7-9%) is associated with poor flavor of soybean oil. Soybean oil with less than 2% linolenic acid would be desirable for improving the quality. Oil in which the linolenic acid (18:3) content has been reduced from 8 to 1% makes it possible to reduce or eliminate the need for chemical hydrogenation and henceforth can achieve the stability and increased shelf life. Oil with elevated levels of oleic acid is less susceptible to oxidative changes during refining, storage and frying. Oil in which the oleic acid (18:1) has been increased from 25 to 80% also have increased stability and longer shelf life. Natural genetic variability for fatty acid composition in commercial soybean seed oil is limited, therefore, additional variability for increasing economical usage is to be created. In this augmentation, induced mutagenesis has been seen to be an excellent tool for creating variability for fatty acid contents in soybean. Induced mutagenesis is regarded as a supplement to the conventional breeding method used to alter the concern genes for reduced linolenic acids and elevated oleic acid content in the cultivars currently grown for commercial production. A significant positive correlation of 100-seed weight with oleic acids and negative correlation with linolenic acids is also useful to select elevated oleic acid and low linolenic acid lines indirectly. The purpose of this paper is to review the methods that have been used to develop the fatty acid modifications, the inheritance of the modifications, the impact of the trait on agronomic and seed characteristics, the methods of phenotypic and genotypic selection, and the commercial status of the modified oils.

 

Mohammad Abul Kalam Azad, Mohammad Imtiaz Uddin, Mohammad Ali Azam (Bangladesh) Achievements in Rice Research at BINA through Induced Mutation (pp 53-57)

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ABSTRACT

Invited Mini-Review: The Bangladesh Institute of Nuclear Agriculture (BINA), since its inception in 1961 as a radio tracer laboratory under the then Pakistan Atomic Energy Commission (PAEC), has released so far 9 improved varieties of rice through induced mutation technique. Of the 9 varieties ‘Iratom-24’ and ‘Iratom-38’ were developed by irradiating the seeds of the rice ‘IR 8’ and released by the National Seed Board (NSB) of Bangladesh in 1974 for boro (December to May) and aus (March to June) seasons. The mutated characteristics of these varieties are shorter crop duration, resistance against bacterial leaf blight (BLB) and medium fine grain size. ‘Binasail’ was also developed by irradiating the seeds of ‘Naizersail’ and released in 1987 for aman (July to December) season with mutated characters like long panicles, more number of grains, medium fine grains with higher weight, early maturing with photo-insensitivity and higher grain and straw yields. ‘Binadhan-4’, ‘Binadhan-5’ and ‘Binadhan-6’ were developed by irradiating F2 seeds of the parents ‘BR-4’ and ‘Iratom-38’ and released in 1998, ‘Binadhani-4’ for aman and ‘Binadhan-5’ and ‘Binadhan-6’ for boro season. ‘Binadhan-7’ was developed from M3 seeds of the cv. ‘Tai Nguen’ of Vietnam. This variety was released in 2007 for aman season with earliness, long fine grain and high yield. Early maturing character of this variety helps to escape drought and insect attack during flowering and dough stages. Moreover, it helps increasing cropping intensity by facilitating timely cultivation of following winter crops. ‘Binadhan-9’ was developed by hybridizing between the local cv. ‘Kalozira’ and an exotic mutant line Y-1281. It was released in 2012 for aman season, also can be grown in boro season. Unlike the parent ‘Kalozira’it has short duration, long and slender grains with slight aroma. Using recent ion beam irradiation technique BINA has already developed some mutant lines that can be grown after harvest of mustard or rapeseed during the first or second week of February and can be harvested after 120 days. These mutant lines produce high yield.

 

Nasya Tomlekova, Svetla Yancheva, Bistra Atanasova (Bulgaria) Molecular Identification of Tomato Mutant Lines (pp 58-64)

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ABSTRACT

Original Research Paper: Molecular characterization of 7 tomato breeding lines (6 mutant and a parent line), maintained in the collection of Maritsa Vegetable Crops Research Institute, Bulgaria, was conducted. Irradiations on an initial genotype of Solanum lycopersicum L. performedby 250 Gy 137Cs generated mutation causing late-flowering. Six tomato mutant lines were advanced to M3 by induced mutation. In this study, both applied, AFLP and ISSR techniques were effective in assessing polymorphic patterns between the studied tomato mutant lines and the corresponding initial ones. The AFLP technique, which has the potential to provide valuable information in a number of areas, revealed discriminating polymorphism among tomato mutant lines and enabled their identification from the initial line with three primer combinations only. AFLP polymorphism was not related to the mutant character. Clear discrimination of the mutant in comparison with the initial tomato lines was revealed by using the ISSR technique. The bulk of the observed morphological evidence, corroborated by the molecular data in this study, indicated DNA variability in the tomato mutant lines.

 

Dafedar H. Tejavathi, Kaivaram Gayathramma, Rajashekharaiah Nijagunaiah (India) Genetic Variability by in Vitro Mutagenesis and Arbuscular Mycorrhizal Fungal Symbiosis among Micropropagated Plants of Agave vera-cruz Miller (pp 65-69)

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Original Research Paper: Agave vera-cruz Mill. is naturally found in semi-arid regions of India and provides a high quality fiber as a good source of income to farmers. Samples for the present study were obtained through direct and indirect organogenesis, arbuscular mycorrhizal fungi (AMF)-treated tissue-cultured plants as well as from tissue-cultured plants derived from exposure to gamma irradiation at 15 Gy for up to 20 min at 2-min intervals (physical mutagen) and ethyl methane sulfonate at 0.1 to 1% for 1 to 5 h (chemical mutagen). These, together with untreated plants were analyzed by amplified fragment length polymorphism (AFLP) markers. A phenotypically distinct variant derived from indirect organogenesis showed more polymorphism followed by mutagen-treated samples. Jaccard’s coefficient of similarity was analyzed by the unweighted paired group method with arithmetic average (UPGMA) method. Plants obtained from mutagen-treated and untreated cultures formed two main clusters. Plants obtained through direct organogenesis and subsequently treated with AMF formed a separate sub-cluster indicating an altered molecular marker pattern. It is feasible to use in vitro culture methods coupled with mutagenesis and AMF symbiosis as a potential tool for increasing genetic variability of vegetatively propagated plants.

 

Sobri Hussein, Anna Pick Kiong Ling, Chee Yang Lau, Siew Ling Ong, Abdul Rahim Harun (Malaysia) Morphological and Biochemical Responses of Eurycoma longifolia Callus to Gamma Irradiation (pp 70-74)

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Original Research Paper: Eurycoma longifolia is commonly used as medicinal plant in South East Asia, particularly for its aphrodisiac property. In this study, the mutation of Eurycoma longifolia callus cultures was induced by gamma irradiation at 20, 40, 60, 80 and 100 Gray (Gy). After three weeks of irradiation, the morphological and biochemical changes of the callus were examined. The radiation sensitivity test determined that 60 Gy was the optimum dose to cause a 50% of decline in the fresh weight (FW) of E. longifolia callus. Even though there was no significant difference on the colour and texture of irradiated and non-irradiated calli, the FW of the calli decreased gradually with the increase of gamma doses. The total soluble protein content recorded 17, 57 and 30% higher than the non-irradiated calli in 20, 40 and 60 Gy, respectively. A further increase of gamma dose to 80 and 100 Gy caused a decrease of 64% in total soluble protein content. Contrarily, gamma irradiation generally brought about a decrease in total phenolic and total flavonoids content. The lowest total phenolic content (0.05 ± 0.01 mg gallic acid equivalents/g FW) was recorded in calli exposed to 40 Gy while the lowest total flavonoid content (0.13 ± 0.01 mg catechin equivalents equivalents/g FW) was obtained in calli irradiated at 60 Gy.

 

Dibyendu Talukdar (India) An Induced Glutathione-deficient Mutant in Grass Pea (Lathyrus sativus L.): Modifications in Plant Morphology, Alterations in Antioxidant Activities and Increased Sensitivity to Cadmium (pp 75-86)

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Original Research Paper: A glutathione-deficient mutant, designated as gshL-1, was isolated in 350 Gy gamma ray treated M2 progeny of grass pea (Lathyrus sativus L.) var. ‘BioL-212’. Its fitness was tested in control (un-stressed) and in four different concentrations (5, 10, 25 and 50 µM) of CdCl2. The mutant, containing only 15% of total glutathione in leaves and 20% of that in roots of mother control (MC) variety, exhibited slow growth, poor root development and significant reduction in biomass production, in comparison to MC plants. The impact was more severe in Cd-treated plants. The huge deficiency in total and reduced glutathione (GSH) content was mainly due to significantly low level of glutathione reductase activity, triggering a massive disruption in antioxidant defense systems in both leaves and roots of the mutant. Interestingly, glutathione biosynthesis was not affected in the mutant. Within ascorbate-GSH cycle, low GSH availability presumably impeded the normal functioning of dehydroascorbate reductase (DHAR), badly hampering the regeneration of reduced ascorbate in the mutant. The cascading effect of low GSH pool was also felt in scavenging of hydrogen peroxide due to below normal activity of ascorbate peroxidase and glutathione peroxidase, although catalase level was significantly high in both untreated and Cd-treated mutant plants. Furthermore, nearly 7-fold decrease in activity of GSH-S-transferases (GSTs) and accumulation of total phytochelatins only 10% of MC plants might led to increased sensitivity of the mutant plant to the imposed Cd stress. The results indicated potentiality of the induced mutagenesis in creation of novel mutants to explore the regulation of antioxidant redox homeostasis, mechanism of reactive oxygen species scavenging and tolerance to metal toxicity in grass pea.

 

Sanjay G. Auti (India) Lhb Mutant – A Novel Mutant of Mungbean (Vigna radiata (L.) Wilczek) Induced by Gamma Radiation (pp 87-93)

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Original Research Paper: In the present investigation an attempt was made to induce mutations in mungbean (Vigna radiata (L.) Wilczek) var. ‘Vaibhav’ by employing gamma radiation with the objective of obtaining novel and desirable mutants. Mungbean seeds were irradiated with 30, 40 and 50 kR doses of gamma radiation and sown in the experimental fields to raise M1, M2 and M3 populations. Mutations were screened at M1, M2 and M3 generations. All three doses of gamma radiation effectively produced various morphological mutations. However, the 50 kR dose effectively produced a novel mutant that showed multiple morphological mutations such as large flowers with dark-yellow petals, dense and thick hairy pods and black seeds. In this study, SDS-PAGE analysis of seed proteins of large flower, hairy pods and black seeds revealed a difference in the banding pattern between the Lhb mutant, other mutants (tall mutant, dwarf mutant, high-yielding mutant and early maturing mutant) and control.

 

Avijeet Chatterjee, Sudhir Shukla, Anu Rastogi, Brij K. Mishra, S. P. Singh (India) Induction of Variability and Selection of Elite Lines for Specific Alkaloids from a Population of Induced Mutagenesis in Opium Poppy (Papaver somniferum L.) (pp 94-102)

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Original Research Paper: Induced mutations often produce abnormalities which cause morphological alterations in external form of plants including colour, shape, size etc. In the present study two white flowered varieties of opium poppy i.e. NBRI-1 and NBRI-5 were subjected to physical (gamma rays), chemical (ethyl methane sulphonate; EMS) and combined (gamma rays + EMS) mutagenesis to determine the effective doses of mutagens to create plants deformities and chlorophyll (chl) mutation. The study also includes selection of elite lines for specific alkaloids especially for thebaine and codeine. The frequency of chl mutations was maximum for the treatment 50 kRad (0.42%) followed by 40 kRad (0.24%) in NBRI-1 while frequency was highest for the treatment 50 kRad + 0.8% EMS (0.86%) followed by 50 kRad + 0.4% EMS (0.60%) and 50 kRad + 0.6% EMS (0.56%) in NBRI-5. Among the chlorophyll mutations, albino was the most frequently screened followed by xantha type at all doses. The variety NBRI-5 was more responsive to the mutagens than NBRI-1 for chl factor. A typical chl variant was observed in M1 generation in the combined dose of 10 kRad + 0.4% EMS in plant no.9 of NBRI-5. The treatments 20 kRad in NBRI-1 and 30 kRad, 40 kRad and 10 kRad + 0.4% EMS in NBRI-5 showed high thebaine in both M2 and M3 generations.

 

Barshile Jagannath, Boddu Apparao (India) Genetic Improvement of Chickpea (Cicer arietinum L.) Cultivar ‘Vijay’ (Phule G 81-1-1) through Induced Mutagenesis (pp 103-106)

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Original Research Paper: In the present attempt three well known mutagens, sodium azide (SA), ethyl methane sulphonate (EMS) and gamma radiation (GR) were employed to induce genetic variability for improvement of locally popular chickpea (Cicer arietinum L.) cv. ‘Vijay’ (Phule G 81-1-1). Seeds were treated with three different concentrations/doses of SA (2, 3 and 4 mM), EMS (8, 12 and 16 mM) and gamma radiation (400, 500 and 600 Gy). Different mutants were isolated and characterized. They included leaf, pod, seed, flower colour and morphological mutants. Five true breeding mutant lines were studied for various quantitative and qualitative traits in the M4 generation. Induced mutant lines showed both positive and negative increases in quantitative traits. True breeding mutant lines in the M4 generation differed considerably in their quantitative traits from the control. The early mutant lines matured 10 to 11 days earlier than the parent cultivar. Gigas mutant plants obtained after 400 Gy gamma radiation were tallest (44.2 cm), with a 2-3 fold increase in pod and seed size over the control. The protein content in the M4 generation ranged from 259.11 to 282.18 mg/g vs 255.59 mg/g in the control. Lower TI activity was observed in the compact mutant (2465.4 TIU/min/g) as compared to the control (3091.5 TIU/min/g). Analysis of variance showed both positive and negative significant increase in the quantitative traits among the mutant lines. The higher heritability coupled with high genetic advance was observed for quantitative traits like number of pods/plant and number of seeds/plant for the mutants in the chickpea cv. ‘Vijay’. Variation was also observed for number of bands electrophoresed in seed protein of mutants.

 

Digambar Dadaji Ahire (India) Correlation Studies and Coefficient of Variation among Fatty Acids and Oil Quality Parameters in Soybean Mutants (pp 107-112)

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ABSTRACT

Original Research Paper: The interrelationships between fatty acids and oil quality parameters were determined by correlation studies to estimate the best selection criteria of mutants for improving oil quality. Correlation analysis results showed that a highly significant (P < 0.01) negative correlation of oleic (MUFA) with linoleic (r = -0.847) and linolenic acid (r = -0.692) (PUFAs) contents is important for selection of mutants with high oleic and low linolenic acid content to improve the oxidative stability index (OSI) of soybean oil. A strong significant but negative correlation was found between linolenic acid and the ω6/ω3 ratio (r = -0.764) and a strong significant positive correlation between OSI and oleic acid (r = 0.938) content indicating improved oxidative stability of the oil while retaining nutritional quality. Mutagenic treatments produced significant genetic variation in fatty acid composition and oil quantity without altering the population means. Among all quality parameters, OSI (50.0%) and stearic acid (62.8%) exhibited maximum variation compared to other traits among the fatty acids.

 

Sonu Goyal, Mohammad Imran Kozgar, Samiullah Khan (India) Effectiveness and Efficiency of Gamma Rays, Ethylmethane Sulphonate and their Combinations in Vigna mungo (L.) Hepper (pp 113-115)

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Short Communication: A systematic study to determine the effectiveness and efficiency of gamma rays, ethylmethane sulphonate (EMS) and their combinations (gamma rays + EMS) were carried out in two urdbean (Vigna mungo (L.) Hepper) varieties namely, T-9 and Pant U-30. Based on effectiveness, the order of mutagens was EMS > gamma rays + EMS > gamma rays in both the varieties. Three criteria viz., pollen sterility, seedling injury and meiotic abnormalities were taken into consideration to determine the efficiency of the mutagens. The efficiency of the mutagens varies with the variety type and the mutagen doses applied depending upon the criteria chosen. Overall, the combination treatments were more efficient followed by EMS and gamma rays. Assessing mutagenic effectiveness and efficiency are beneficial to screen mutagen doses which are potent to increase genetic diversity among self-pollinated crops like urdbean for successful plant breeding strategies.

 

Asnake Woldemedhin Fikre (Ethiopia) Gamma Irradiation-Derived, Methionine-Enriched Mutant Lines of Lathyrus sativus L. (pp 116-118)

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Short Communication: Methionine (Met), an essential sulphur-containing amino acid, is supposed to protect from lathyrism disease caused by over-consumption of Lathyrus sativus (grass pea). There is a strong and positive association between moisture stress and the biosynthesis of the crippling lathyrism causative molecule, 3-(N-oxalyl)-L-2, 3-diamino propionic acid (b-ODAP). Seeds of L. sativus local cv. ‘Debre Zeit’ were irradiated using 40 kR gamma cell irradiation aimed at genetic alteration in favour of overproduction of Met-based seed proteins. The amino acid determination in seeds were analysed using HPLC with pre-column PITC derivatization. Three morpho-phenotypically distinct mutant lines were identified and selected from irradiated clusters, which displayed glittering deep green leaves, stem and pods, smaller leaf and plant size, and reasonable yield compared to the parental line. Observation of root growth response in ethionine media supported the phenotypic and chromatograph findings. Chemical analysis of seeds revealed that the putative mutants had 63% improved Met over the parent (control). This level shifts the Met supply capacity of grass pea from 25% in the parent line to 50% in the altered putative mutant lines.

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