HERE 59-21 INDUCED MUTATIONS AS A TOOL FOR IMPROVING WORLD FOOD SOURCES AND INTERNATIONAL COOPERATION IN THEIR USE' HEAD, PLANT BREEDING AND GENETICS SECTION, JOINT FAO/IAEA DIVISION OF ATOMIC ENERGY IN FOOD AND AGRICULTURE, INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, AUSTRIA (Received.June 29th. 1967) HE recent food crisis in India has shocked the world into realiz a t' ion T that the old gloomy prediction of Malthus may yet come true. Although the generous help of nations having food surpluses has so far prevented this situation from turning into a major disaster, these surpluses have now dwindled. The problem of feeding 500 million Indians was bad enough yesterday, but this morning, and every morning, there are over 30,000 more mouths to feed in India alone. Food production is not increasing at the same rate as the human population, and a large majority of the present world population is already undernourished. It is thus clear that mankind faces two tasks which must take priority over almost everything else: controlling population growth, and increasing food production. We know how the rate of population growth could be reduced. The problem is how to apply the control measures. We know also that it is possible to multiply the present food production levels. We have at our disposal a variety of techniques, from fertilizer application through disease and pest control to increasing plant productivity. The problem is, however, so enormous and so urgent that we must now apply all available means, if only for the time being, to reduce the widening of the gap between increase in population and food production. Breeding of crop plants capable of high yield in response to fertilizer applications and having resistance to diseases and pests is one of the most promising means of raising food Lecture given at a Meeting of the Swedish Mutation Group held at the Wenner- Gren Centre, Stockholm, on 14 February 1967.
376 BJ~RN SIGURBJ~RNSSON production. In this giant task no effort can be spared and no promising approach can be neglected. In breeding crop plants capable of high performance under modern agricultural conditions, the artificially induced mutations offer the plant breeder a tool to break through the limitation of presently known variability in plants, and also to enable him to introduce specific improvements into productive crop varieties without otherwise affecting their good attributes. Yet, surprisingly, there are many who disregard this additional tool and emphatically claim that any improvement desired can be bred on the basis of present variability. It has been especially claimed that this method is too sophisticated for use by developing countries. They should stick to old and proven techniques and leave it up to the more advanced countries to play around with esoteric radiations and chemicals. For example, in 1965, a thick book on rice appeared on the market in its revised fourth printing. Out of several hundreds of pages less than one was devoted to induced mutations in rice breeding, enough to flatly conclude that there is fortunately no necessity to resort to artificial mutations, for the multitude of varieties provides a prodigious range of unexplored variability upon which the rice breeder can draw in his endeavors to improve this crop (GRIST, 1965). During that same year, as a result of gamma treatments of rice seeds by a participant in one of the international programmes of the Joint FAOlIAEA Division, a new rice variety was officially selected for release in Japan, only five years after initial treatment (GUSTAFSSON and GADD, 1966). This variety, Rei Mei (Fig. I), represents a significant improvement in lodging resistance in an otherwise acceptable rice variety. The new variety is thus able to respond much better to increased fertilizer application and yield better. Other induced mutant lines of rice have been selected in Japan which mature 40-50 days earlier than the mother strains (Fig. 2). This remarkable improvement is made without affecting other desirable attributes of the strain, such as cooking quality and yielding ability (KAWAI, 1966). This can be compared to a new rice variety IR-8 produced in 1966 by the International Rice Research Institute, which presents a dramatic increase in yielding ability and a wide adaptability. Selected mainly for strong straw and yielding ability among hybridization progeny, the new variety also inherited a grain quality which in many countries borders on being unacceptable. Two of the participants in our rice niutation programme in Asia have been asked to apply the induced mutation technique in an attempt to correct
Fig. 1. The second plant from the right is the new mutant variety of rice, Reimei, bred at the Aomori Prefectural Experiment Station in Japan following treatment of seeds of the variety Fujiminori (far left) by one of the FOA/IAEA cooperators. The new variety which is the first induced mutant variety of rice officially released for cultivation has shorter and stronger culm and is highly resistant to lodging. It has the same yield as the original variety. It was selected for release five years after the radiation treatments of the seeds. The other plants in the photograph are promising rice strains obtained by cross breeding. (Photograph received from T. KAWAI.)
378 BJORN SIGURBJORNSSON Fig. 2. The rice plants in the centre and left reach maturity up to 50 days earlier than the original variety on the right. The early line was developed at the National Radiation Breeding Institute in Japan following seed treatments with gamma irradiation by one of the FAO/IAEA cooperators. this defect of the otherwise outstanding variety. One of them, Dr. SWAMINATHAN of New Delhi, India, has reported that he has been SUCcessful in correcting a similar defect in a related variety by using induced mutations (NATARAJAN, 1966). In order to appreciate the potential contribution of induced mutations and to understand the controversial attitudes toward this method of plant breeding, one must know something about their nature and r81e in living things. In fact, this controversial attitude can be traced to the very nature of mutations: Mutations and combinations of different mutations are ultimately the source of all variability in living things. The controversy stems from the fact that the vast majority of mutations have a harmful effect on the organism. Yet, all present-day forms of life, from the lowest organisms through plants and animals including man, have arisen during natural evolution through environmental selection for those rare mutations which contributed to the survival and reproductive fitness of the organism.
WORLD FOOD SOURCES 359 Unfortunately, the selection criteria which lead to the evolution of organisms better equipped to survive and reproduce under natural conditions, are not necessarily the same as those applied by a plant breeder when selecting a crop variety for optimum performance under modern conditions of mechanized farming and high levels of soil fertility from artificial fertilizers. In fact, they are often quite the opposite. Mutations occurring before the beginning of conscious breeding of crop plants which might have contributed to agronomic performance, would not have been selected for naturally, unless they also contributed to the fitness of the organisms in the natural environment. Therefore, it cannot be claimed that all possible useful variability already exists. The so-called conventional plant breeding methods based on hybridization, recombination and selection, are thus primarily dealing with the results of natural selection and therefore with those characteristics, created through mutations, which have been selected for because of their ability to compete for survival. In addition, plant breeders naturally make use of such mutations which occur spontaneously in their breeding material. Such mutations have been of considerable value. As an example of this is the successful new rice variety IR-8 which I mentioned. Its success is to a large extent based on its short, strong straw which can be traced to a spontaneous mutation in one of its parent varieties, Dee-geo-woo-gen (SWAMINATHAN, 1966; IRRI Press Release, 1966), Another example is Dr. Sengbusch s successful isolation of spontaneous mutants in lupines, resulting in alkaloid-free varieties which opened the way for domestication of this plant for use as animal fodder (SENGBUSCH, 1942). A third recent example is the improvement in nutritional value of maize through the discovery of the Opaque-2 mutant which increases lysine content considerably (MERTZ et al., 1965). Countless other examples can be found of the selection of recent spontaneous mutations which have resulted in superior varieties of cereals, vegetables, forage crops, fruit trees and ornamentals ( GUSTAFSSON and GADD, 1965 and 1966). Should we then be content to wait for the occurrence of spontaneous mutations and hope to spot them in our breeding material? Answering in the negative, it will be sufficient to point out two facts: first, the rate of spontaneous mutations is exceedingly low. In a cereal field one may expect to observe one plant out of 10,000 to 100,000 containing a newly arisen mutation. This mutation is very likely to be deleterious, since only one out of a thousand or more mutations turns out to be beneficial in some way. Second, when one applies ionizing radiations or chemical
380 BJ~RN SIGURBJ~RNSSON mutagens, it is possible to increase the rate of occurrence of mutations so that every plant in a treated population will contain at least one mutation. Thus, the mutation rate can be increased from 10,000 to 100,000 times the rate at which mutations occur spontaneously. It is then not surprising that the enormous potential usefulness of induced mutations for plant breeding has stirred the imagination of geneticists from DEVRIES at the turn of the century, through such scientists as NILSSON-EHLE, MULLER and GUSTAFSSON. Studies on induced mutations started seriously following MULLER and STADLER S discovery of the fact that X-rays could significantly increase the mutation rate. When radioisotopes became generally available after the Second World War, interest in induced mutations increased sharply. Unfortunately, the exiciting potential of this method and the resulting enthusiasm for practical applications far outpaced the progress in research, leading to an understanding of the process and the development of efficient techniques of application. There was a period when plant breeders all over the world sent seeds, sometimes in great quantities, to be treated by these mysterious rays which seemed to be the answer of the atomic age to the plant breeder s dreams. They would then plant the seeds and wait in excitement for something to happen. When in most cases nothing significant happened, they would give up in disgust and return to other methods of breeding. This gave rise to a period of disappointment and pessimism, and this premature rush into practical applications did indeed hamper progress in research leading to sensible applications of induced mutations. Fortunately, throughout this period there were scientists who unwaveringly kept on with the research on basic as well as applied aspects of induced mutations, and in the process, were not only able to produce outstanding crop varieties but also to restore faith in the unique and challenging potential use of induced mutations. It is a great pleasure to acknowledge here that outstanding among these scientists were members of the Swedish Mutation Group under the leadership of Professor KEE GUSTAFSSON, who have probably contributed more to progress in this field than any other school, by providing both a theoretical basis as well as examples of practical achievements. The basis for the eventual success of this method is the understanding gained of the nature of the mutation process and of the effect of the various mutagens, under a variety of conditions, on living matter, particularly on seeds, which gives rise to the development of efficient methods of mutagen treatment and handling of the treated progeny to isolate the productive mutants.
WORLD FOOD SOURCES 381 The impact of this Swedish contribution is felt directly in mutation research throughout the world and is far out of proportion to the size of the country and the number of its scientists. Recently, there have been rather remarkable practical developments in the use of induced mutations in plant breeding which begin to substantiate the early expectations. I have mentioned the Japanese rice. A few other examples will be mentioned. Promising mutant lines of rice have been developed on Formosa, in India, and in France, which are in advanced stages of testing. The Japanese have released a new shortstrawed and lodging-resistant variety of soybeans which matures three weeks earlier and yields equal to the mother variety (Fig. 3). They are about to release an early, high yielding and lodging-resistant strain of oil rape (Fig. 4). A new variety of winter barley has just been released in the U.S.A. It is named Luther after the late Dr. LUTHER SMITH and was produced at Washington State University following treatments with des in 1959. This is the first commercial crop variety released following treatment with a chemical mutagen (Anonymus, 1966). Indian researchers have produced mutant lines of wheat which have branched ears and a 50 per cent increase in protein content. They have also succeeded, through radiations, to synthesize all species of wheat from one variety of bread wheat (SWAMINATHAN, 1965 and 1966). More importantly, this method is beginning to find its place generally in plant breeding programmes where it belongs as a unique and effective additional tool for use by plant breeders in their efforts to improve world food resources. Despite the significant rewlts which have been achieved recently, it is true that induced mutations have been used, and are still used, haphazardly, according to the look for something method by a number of plant breeders. This is particularly true in many developing countries where plant breeders using induced mutations are working in relative isolation and are often lacking adequate library facilities to keep up with new developments. It is thus one of the primary objectives of the international activities in this field of the Food and Agriculture Organization of the United Nations, and of the International Atomic Energy Agency, to render assistance and guidance to mutation workers and to bring about a Since this article was written, a new mutant wheat variety, Sharbati-Sonora, has been released in India following gamma-ray treatments of seeds of the Mexican variety Sonora-64. The new variety has amber grain color which is preferred by Indian consumers to the red grain color of Sonora-64. 25 - Heredifas 59
Fig. 3. The soybean variety shown on the left is a new mutant variety, Raiden, bred at the Tohoku National Experiment Station, Japan, following treatments with gamma radiation of seeds of the commercial variety Nemashirazu, shown on the right. The new variety reaches maturity 25 days before the mother variety, has a shorter stem and equal yield. (Photograph received from T. KAWAI).
Fig. 4. Shown on the right is a line of oil rape, Tokai 23, bred at the Tokai Regional Agricultural Experiment Station, Japan, from the commercial variety Murasaki-Natane, shown on the left, following treatments with gamma rays and selection for shorter and stronger stem. The mutant line is highly resistant to lodging, matures 10 days earlier than Murasaki-Natane and is high yielding. (Photograph received from T. KAWAI.)
384 BJORN SIGURBJORNSSON degree of cooperation and coordination aniong them, which would foster more rapid progress in the effective use of this tool to improve the quality and quantity of food sources. No less important is to advise against inappropriate and untimely use of these methods in plant breeding. International cooperation in this field was given an important stimulus when in 1964 the FL40 and IAEA decided to join forces by forming a Joint Division of Atomic Energy in Food and Agriculture. This Division is active in every field of agricultural research and training. It includes a Section on Plant Breeding and Genetics. It was immediately clear that there was R great need to stimulate international coordination and cooperation among research workers in this field. Although this need was most urgent in the developing countries, it was soon evident that research workers in even the most highly advanced countries would also benefit from increased cooperation and they have indeed sought the help of the new Division to bring this about. It is little known among those who desire such assistance that although international organizations have the status and the appropriate frame of reference for promoting international cooperation, they are pitifully short on financial resources. It was. therefore, necessary from the outset to carefully choose selected areas of concern and to limit the activities to the most important crops. We chose to concentrate in the major food crops, primarily the main cereal sources of carbohydrates, rice and wheat, but are also preparing to develop international programmes of research for improving the quality and quantity of cereal protein as well as the protein-rich legumes, particularly soybeans. Within this framework, the Section has the following three primary objectives: first, promotion and coordination of research leading to the development of more efficient methods of inducing and utilizing mutations; second, fostering cooperation between and rendering assistance to mutation workers engaged in breeding some of the world s major food crops; and third, establishment of systematic international testing of induced mutant lines and varieties in some of the major food crops, and standardization and mechanization of methods of recording and analyzing data in international trials and mutant collections. In addition, the Section has technical responsibility for various projrtcs of Technical Assistance to.developing countries, including expert services, provision of scientific equipment and awarding of fellowships. It also technically supervises scientific meetings, training courses and publication in the field. Furthermore, it supervises the research, service and training programme of the Plant Breeding and Genetics Unit of the
WORLD FOOD SOURCES 3x5 ~- IAEA Laboratory at Seibersdorf near Vienna. During the first two and a half years of its operation, the Section has, in accordance with its three primary objectives, developed several international programmes which I will describe briefly: International mutation group A group of over 20 scientists from 11 countries of Europe, America and Asia cooperate within the framework of a coordinated programme of research on the production and use of induced mutations in plant breeding. These scientists work with many crop species, mostly cereals. Nearly all of them cooperate with the IAEA on the basis of research agreements receiving no financial assistance from it (Fig. 5). One of the principal tasks of this group is to study means of improving the efficiency of mutation induction to gain a degree of control over the process. The objective is to induce a maximum number of desired mutations with minimum physiological and genetical damage to the plant. The other main task of the group is to study means of improving the utilization of desirable mutants in plant breeding. This includes methods of handling the treated material and subsequent generations, and the utilization of the selected mutants as new varieties or their use :IS parent material in cross-breeding programmes. This group also serves as an informal advisory body to all activities of the Plant Breeding and Genetics Section as well as to the corresponding unit of the IAEA Laboratory at Seibersdorf. The participants met at the first coordinating panel meeting in Vienna, 17-21 January 1966. They reported on their research work, discussed and coordinated their plans, and prepared technical recommendations as well as reconimendations concerning the programmatic activities of the Section. The proceedings have been published in the Panel Reports Series of the IAEA. The nest coordinating meeting of this group wilt take place in Vienna in September 1967. Manual on mutation breeding A part of the responsibility of the group mentioned above and associates working with them, is to contribute to the preparation of a Manual on Mutation Breeding which the Joint FAO/IAEA Division plans to publish. The preparatory work was begun in 1964 under the auspices of the IAEA by Professor. ~KE GUSTAFSSON who has compiled
Rome Pisa Bologna Fig. 5. Location of participants in the FAO/IAEA Coordinated Programme of Research on the Production and Use of Induced Mutations in Plant Breeding in 1966.
WORLD FOOD SOURCES 387 comprehensive reviews of the radiobiology and mutation breeding work in several major crop plants. These reviews have been published as a series in Hereditas (GUSTAFSSON and GADD, 1965 and 1966). Shortened versions of these reviews will be included in the Manuel together with its major part dealing with methodology and necessary background information. The need for such a Manual is urgent, particularly for breeders who work in countries where library facilities are unsatisfactory and opportunities to consult with colleagues are limited. It is hoped that this Manual will help breeders in deciding when the use of induced mutations can be of the greatest benefit in their programmes, and spare then the effort of repeating preliminary surveys of general radiation effects before starting the practical applications. During discussions at the Panel Meeting in January, it was brought out that there are many procedural aspects on which there is no agreement and that in some cases efficient procedures do not exist which can be recommended for general use. The laboratory unit at Seibersdorf was asked to study some of these procedures, particularly concerning seedling growth techniques, in an attempt to discover and test useful methods. At the next meeting it is planned to devote most of the time to reach an agreement on methods to be recommended in the Manual. Neutron seed irradiation programme A Neutron Seed Irradiation Programme is in the process of getting under way. Its primary objective is standardization of methods of exposing seeds to neutrons in reactors and of measuring and reporting dose. Under contract with the IAEA and in collaboration with FAO/ IAEA staff, the Austrian Atomic Energy Research Organization has developed a seed irradiation facility (lead and boron pot with a revolving specimen capsule, Fig. 6), for use in pool-type reactors. Recommendations for standardized methods of measuring and reporting of dose have been developed by groups of biology, chemistry and physics experts. Contracts have been concluded with several countries (India, Thailand, Philippines, Bulgaria, Austria) to install the irradiation facility and to carry out coordinated studies (SIGURBJ~RNSSON et al., 1967). Several additional countries are expected to join the programme during 1967. The IAEA Laboratory at Seibersdorf is testing a technique of using barley seedling growth as an indicator of biological response for comparing different reactors. The first coordinating meeting was held
388 BJORN SIGURBJORNSSON SEFD /RRADfATlON FACILITY 90@ Fig. 6. Diagram of the facility for exposing seeds to neutrons in swimming-pool reactors, developed by the Austrian Reactor Group at Seibersdorf under contract with the IAEA. The seed capsule inside the boron and lead shield is lowered through a shaft into the shield and rotated during exposure. This type of facility is now being used for irradiation of seeds and other materials in reactors in the Philippines, Thailand, India and Austria, as part of the FAO/IAEA Coordinated Seed Irradiation Programme. (Diagram recived from A. BURTSCHER and J. CASTA.)
WORLD FOOD SOURCES 389 in Vienna in July 1966; a working group meeting was held in Vienna in December 1966, and the second coordinating meeting will be held in Vienna in December 1967. Other studies within this programme will include radiosensitivity to neutrons of crop species and the use of neutrons for induction of useful mutations. The proceedings of the 1966 meetings were published in 1967. Rice mutation breeding programme In 1964 a coordinated programme of research on the use of induced mutations in rice breeding was established for Southeast Asia. The participating scientists are located in Brazil, Ceylon, India,.Japan, Korea, East and West Pakistan, the Philippines, the Republic of China, and Thailand. A rice breeding project in Guyana is also associated with this programme (Fig. 7). The individual projects receive financial support under the Agency s research contract programme and a part of this money is used to pay for the participants travel to annual COordinating meetings. The first meeting was held in Bangkok in 1965. It was evident that in spite of considerable research activities in this field in Southeast Asia there is an urgent need for coordination of this research which all has the same objective: production of improved rice varieties. This meeting was the first time for many of these scientists to establish personal contacts. The papers presented and the recommendations made were published in the International Rice Commission s Newsletter. The second coordinating meeting was held jointly with rice insect experts in Manila in February 1966. It was brought out at the meeting that several promising mutants of rice have already been produced: the Japanese have been mentioned; mutants produced in India have resistance to bacterial blight, improved grain quality and are 10 to 20 days earlier maturing. Taiwan mutants have improved disease resistance, better straw and higher yield. It was decided to establish uniform international trials to test these mutants in the participating countries. In addition to the research contractors, several expert consultants were invited to take part in the discussions and to advise on the research projects at these meetings. The laboratory unit at Seibersdorf has provided mutagen treatment services to some of the projects in the rice programme and is training scientists from some of the countries. In cooperation with the Field Food Crops Branch of the FA0 and
Fig. 7. Location of participants in the FAO/IAEA Coordinated Rice Mutation Research Programme. w co 0
WORLD FOOD SOURCES 391 through the Plant Breeding and Genetics Unit at Seibersdorf Laboratory, two cooperative projects have been organized for the induction of resistance to blotch (Septoria spp.) in wheat. One of these is carried out in Kenya and the other in Argentina. Some of the radiation treatments of seeds are carried out at Seibersdorf and the subsequent handling of the treated progenies is carried out in the cooperating countries. It is planned to establish in 1968169 a coordinated programme of research on the use of induced mutations in protein-rich plants, particularly legumes (soybeans, groundnuts, beans, peas, etc.). Uniform international trials of wheat and rice mutants The Section, in cooperation with the FA0 Field Food Crops Branch and the Casaccia Nuclear Energy Centre in Italy, established in 1966 uniform international trials in the Near and Middle East of promising lodging and yellow-berry resistant mutants of durum wheat. These mutants were developed by Professor G. T. SCARASCIA-MUGNOZZA at the Casaccia Centre and have been thoroughly tested in Italy. The trials are conducted within the framework of the FA0 Near East Wheat and Barley Production and Improvement Programme which has participants in 17 countries. The trials were grown in ten countries in 1966 (Tunisia, Libya, Egypt, Lebanon, Syria, Iran, India, Turkey, Cyprus and Italy) and in 1967, Israel and Greece joined the programme (Fig. 8). Common checks as well as local controls are included in the trials and uniform methods of observation and scoring are used and recorded in standardized, computer-printed field books. A training course will be held in Italy in 1969 to train breeders from the area, mainly to teach them how to handle plant populations following mutagen treatment. The results obtained in 1966 have shown that some of the mutant lines have had the highest yield as compared to controis in most of the participating countries. This represents mutation breeding in which a direct and significant increase in yielding ability was brought about. The laboratories at Seibersdorf and Casaccia have also offered to provide mutagen treatment services to breeders participating in the programme together with such assistance and guidance with their projects as needed. Fig. 9 shows one of the experiments of these trials. Under the framework of the Coordinated Rice Mutation Breeding Programme and in cooperation with the International Rice Research
Fig. 8. Location of the FAO/IAEA Uniform International Trials of Durum Wheat Mutants in 1967. co m
WORLD FOOD SOURCES 393 Institute, Uniform International Trials of indica rice and observation plot tests of japonica rice have recently been conducted in a number of Southeast Asian countries. The complete results from 1966 are not known but the trials are continued in 1967 over a wider area. The trials are coordinated by IRRI and include mutant lines developed in India, Japan, the Republic of China, Thailand, and the U.S.A., in addition to appropriate local controls, as well as the new IR-8 variety as a common control. It is also being contemplated by FA0 and IAEA staff to organize an international scheme to enable plant breeders to grow two (or more) generations per year by establishing reciprocal seed multiplication plots in the Northern and Southern Hemisphere in order to reduce the time required to breed a new crop variety. Standardization of procedures in crop research data recording International cooperation in research is now increasing SO rapidly that communication difficulties are already presenting a hindrance. The programmes described above represent only a few examples of the widening scope of international activities in biological research. Differences in technical language for data recording can seriously limit the progress and understanding that the various programmes could achieve. It is possible to break through the barriers created by different languages and different approaches, by the use of standard reference materials such as color charts, illustration diagrams, codes, indices, etc. In cooperation with the Plant Production and Protection Division of FA0 and the International Biological Programme, work is now being developed toward standardization of crop research records and mechanization of processing. Several study groups, led by Prof. C. F. KONZAK, have met to discuss the development of standard record formats and procedures. The Joint Division s Uniform International Trials of rice and wheat already make use of computer-printed field books under this system. Formats are being developed for recording mutant and other genetic stock collections for computer handling. Adaptation studies led by Dr. K. W. FINLAY, are being standardized under the IBP and FA0 and the FA0 hopes eventually to establish world-wide germ plasm collection records (KONZAK, 1966). A meeting of experts in this field is planned for the fall of 1967.
394 BJGRN SICURBJijRNSSON Research by the plant breeding and genetics unit of the IAEA Seibersdorf laboratory The Joint FAOIIAEA Division has the scientific and technical responsibility for the programme of this Unit of the IAEA Seibersdorf Laboratory. This Unit, headed by K. Mikaelsen, operates in such a fashion as to integrate its functions of service and research training into the overall plant breeding and genetics programme of the Joint Division. Thus, the niain objectives of the Plant Breeding and Genetics Laboratory which was started in mid-1965, are to carry out research on methods of application of ionizing radiations and other mutagens in practical plant breeding, to give assistance and advice on the various programmes and projects of the Joint FAO/I.4EA Division in regard to mutagen treatments. Furthermore, this Unit trains scientists in mutation breeding research. Various projects on mutagenic effects of gamma and neutron irradiation are being carried out, particularly relating to neutron dosimetry and the measurement of biological effectiveness of the various types of ionizing radiations in reactors. Projects are also under way for studies of chemical mutagens, particularly EMS and des. The main objectives are comparisons with ionizing radiations including effect of combination treatments; studies of effects of various pre- and post-treatments and on dry-back methods to facilitate chemical mutagen treatment service for participants in the international programmes. Seeds of rice, wheat, barley, beans and tomatoes have been submitted to mutagen treatments for various projects in Asia, Africa, South America, and Europe, and the laboratory is cooperating and assisting with the projects. The cooperating laboratories provide Seibersdorf with all information and results deriving from these experiments. This accumulation of information is of importance for assisting and guiding mutation breeding in Member States of FA0 and IAEA. Another object of the laboratory is to provide training to scientists in mutation breeding and to assist in the organization of training courses on the use of mutations in plant breeding. At present the laboratory has four trainees in plant breeding and genetics. Other activities in this field, sponsored or supported by the FA0 and IAEA, have included several symposia: in Ithaca 1959, in Karlsruhe 1960, in Rome 1964, and in Tokyo and Vienna 1966. During the first two and a half years of this joint venture of FA0 and IAEA, a number of international programmes have been estab-
WORLD FOOD SOURCES 395 lished, which have fostered cooperation among scientists the world over. The resulting coordination in some of the fields dealt with, has already contributed to more rapid progress in the use of nuclear methods in agricultural research and has helped to place this technique in its proper perspective as an important and unique additional tool to further research toward more and better food. It is clear that induced mutations as a plant breeding tool have come of age and that the effect of their unique contribution is being felt in a number of plant breeding programmes. There is also an increasing awareness of the opportunities afforded by this method, which enables the plant breeder to break through the limits set by his present gene sources and help open the way for that dramatic increase in food production which, in light of the population explosion, is needed to alleviate the increasing threat of hunger on a universal and catastrophic scale. Literature cited Anonymus 1966. Chemical mutation produces new barley variety. - Crops Soils Mag. (Dec. 19661, p. 28. GRIST, D. H. 1965. Rice. - 4th ed. Longmans, Green and Co., London. GUSTAFSSON, A. and GADD, I. 1965. Mutations and crop improvement. VI. The genus Avena L. (Gramineae)- Hereditas 53: 327-388. - 1966. Mutations and crop improvement. VII. The genus Oryzrr L. (Gramineae). - Jbid. 55:273-357. International Rice Research Institute Press Release, November 28, 1966. KAWAI, T. 1966. Mutation breeding in ricejapan. - Rep. 2nd Coordin. Meet. Use Induc. Mutat. Rice Breed., Manila, 21-25 Feb. 1966. KONZAK, C. F. 1966. Report of an expert group which met to consider International standardization, integration and mechanization of crop data recording and processing. - Mutations in plant breeding (Int. Atomic Energy Agency, Vienna 1966), p. 241-248. MERTZ, E. T., VERON, 0. A., BATES, L. S. and NELSON, 0. E. 1965. Growth of rats fed on opaque-2 maize. - Science 148: 1741-1742. NATARAJAN, A. T. 1966. Personal communication. SENGBUSCH, R. VON. 1942. Susslupinen und Ollupinen. Die Entstehungsgeschichte einiger neuer Kulturpflanzen. - Landwirtsch. Jahrb. 91: 723-880. SIGURBJ~~RNSSON, B., KONZAK, C. F., MIKAELSEN, K. and AHNSTROM, G. 1967. Neutron Irradiation of seeds in research reactors. 1)evelopment of an international programme. - In press. SWAMINATHAN, M. S. 1965. Artificial transmutation of the gene. - J. Sci. Ind. Res. 24: 217-220. - 1966. Progress report for research agreement No. 338/CF to the International Atomic Energy Agency. - 1966. Use of induced mutations. - Indian Farming (Special Rice Number, Sept. 1966), p. 34.