Induced mutations for enhancing nutrition and food
production
S. Mohan Jain* and P. Suprasanna**
*Department of Agricultural Sciences, University of Helsinki, PL-27, Helsinki, Finland
Email: [email protected]
**Nuclear Agriculture & Biotechnology Division, Bhabha Atomic Research Centre,
Trombay, Mumbai 400 085. Email: [email protected]
Received March,15 , 2011
Accepted May, 14, 2011
Geneconserve 40 : 201 – 215 (2011)
Abstract
Issues of enhanced food security depend primarily on increasing agricultural production.
Given this challenge, existing and new, appropriate technologies need to be integrated
into agricultural research, to focus on the problems related to improving nutritional
security. Among the different approaches, mutagenesis and the isolation of improved or
novel phenotypes in conjunction with conventional breeding programmes can result in
mutant varieties endowed with desirable traits. Induced mutations play an important role
enhancing nutritional quality in crop plants. Several mutant genes have been successfully
introduced into commercial crop varieties that significantly enhance the nutritional value
of crops. This review briefly outlines the aspects of induced mutations and nutritional
quality in crop improvement.
Introduction
Agricultural development has always been on the move towards increasing crop
productivity and exploiting natural resources. Such a developmental program necessitates
coordination between agricultural activities, ecosystems, and human society. It is
imperative that sustainable use of natural resources should be prudently managed in
conjunction with the advancement in the knowledge gained from science and technology.
Today human population is growing rapidly especially in the developing countries
whereas in the developed countries the situation is just the reverse. Global food security
continues to be the centre stage issue and plant breeders are under pressure to sustain the
food production to meet the demand of ever-growing human population. Further to the
problem, the erratic climatic change because of its direct effects on both food production
and food security has mounted the pressure to develop sustainable (Jain 2010a). Several
factors such as abiotic and biotic stresses, industrial pollution, deforestation, loss of
genetic diversity, water shortages and so on are responsible for having a negative impact
on food production. The world population is expected to reach 7 billion in the next 20
years, and 10 billion by 2050. The question is, Can we feed the world and sustain
Article
nutrition balance in the diet at the affordable price with the available technologies? The
answer seems to be not so positive even though plant breeders are making all out efforts
to sustain food production and nutrition to make genetic improvement of plants by using
conventional and modern tools. Pundit Jawaharlal Nehru, the great former prime minister
of India, remarked in the late 50s that “Everything else can wait but not agriculture” and
this remark remain relevant today. There is no short-term magic formula to solve the
world’s food problems.
The genetic variability is highly desirable for developing new cultivars, which is induced
by mutagen treatments and natural spontaneous changes. The spontaneous mutation rate
is pretty low and can’t be exploited for breeding and that is why artificially mutations are
induced with physical and chemical mutagen treatment. Quite many useful genetic
changes have been induced by mutagen treatment including high yield, flower colour,
disease resistance, and early maturation and so on in crop, vegetables, medicinal herbs,
fruit and ornamental plants. So far, over 3000 mutant varieties have been officially
released over 60 countries including rice, wheat, barley, sorghum, legumes, cotton, edible
oil, ornamental plants and fruits (www-mvd.iaea.org). China and India are the major
producers of mutant varieties to feed their ever-growing human population. Among all
crops, the released highest number of mutant varieties is in rice. In 2005, The
International Atomic Energy Agency (IAEA), Vienna, Austria was conferred Nobel Peace
Prize for its contributions to the peaceful applications of nuclear energy in various fields
including food and agriculture. This award was a shot in the arms by recognising the
major contributions made with the use of nuclear energy in enhancing food production
and economic benefits worldwide. The year 2008 marked the 80th
anniversary of mutation
induction in crop plants, when an international symposium on induced mutations in plants
was organised in Vienna, Austria (Shu, 2010).
The foremost objective of plant breeders and geneticists is to sustain food and nutrition
security and that is why the selection of major crops has become crucial for meeting these
goals under the existing arable land, and climate change. Malnutrition with respect to
micronutrients like vitamin A, iron, and zinc affects more than 40% of the world’s
population. Micronutrient deficiencies are common in many developing countries and are
typically due to inadequate food intake, poor dietary quality and poor bioavailability (Fig.
1, Ramakrishnan 2002). For example in wheat, zinc is quite low in grain and
consequently deficient in human diet among the developing countries, and to supplement
it needs zince enriched wheat grains at the farmer’s field (Hussain et al 2010). World
major crops like rice, wheat, maize, barley etc., would require continuous modifications
for sustainable food production, where as nutrition security would be maintained by
improving legumes, vegetables, and fruits. For example banana and plantain are among
the world’s major food crops, and are considered as the poor man’s fruit crop, and have
potential to provide subsistence diet and nutrition to millions of people. However, the
major problem with fruit breeding work is long life cycle of many fruit crops, which
varies from 3-25 years or even more. The large juvenile period has hampered fruit
breeding work. In fruit crops, mutagenesis has been quite useful in isolation of useful
mutants such as plant size, blooming time, fruit ripening, fruit colour, and resistance to
pathogens. Another major fruit crop is date palm (Phoenix dactylifera L.), a major source
of human nutrition including vitamins, sugars, fat, salts and minerals, and oils; and has
high potential to produce bio-ethanol (Jain 2011; Jain et al 2011).
Induced mutations
Mutations are induced by physical (gamma radiation, high and low energy beams) and
chemical (ethyl methane sulfonate, EMS) mutagen treatment of both seed and vegetative
propagated crops. The mechanism of mutation induction is that the mutagen treatment
breaks the nuclear DNA and during the process of DNA repair mechanism, new
mutations occur randomly and are heritable. The changes can also occur in cytoplasmic
organelles and also results in chlorophyll mutations, chromosomal or genomic mutations
that enable plant breeders to select useful mutants such as abiotic and biotic stresses and
others. By induced mutations, mutants with multiple traits can be identified. The chances
of survival varieties are much higher under the climate change. In Vietnam, eight rice
mutant varieties have been developed with multiple traits like high quality, tolerance to
salinity and short duration allowing three harvests per year providing farmers an extra
income of 300 million US dollars. Moreover, mutant varieties are readily accepted by the
consumers. Induced mutations have played a pivotal role in enhancing world food
security, since new food crop varieties with various induced mutations have contributed to
the significant increase of crop production at locations people could directly access
(Kharkwal and Shu 2010).
Among physical mutagens, gamma radiation has been widely used for mutation induction
for both seed and vegetative propagated crops. Recently ion energy technology- heavy ion
beam (HIB) and low energy ion beam (LIB)- is being for mutation induction in wide
ranging crops. HIB is predominantly used for inducing mutations in plants (Jain, 2010a).
They transfer linear energy transfer (LET) and enhances the induction of higher biological
effects. Several Arabidopsis mutants have been obtained including deletions, insertions,
and chromosomal translocations by HIB.
Plant cell tissue culture has made tremendous progress towards plant regeneration from
all major food and horticultural crops. Micropropagation via organogenesis is routinely
used for clonal propagation of ornamental plants and other vegetative propagated plants,
especially woody and fruits trees. Explant (shoot meristem, adventitious buds, and
microspores) is directly treated with mutagen and direct shoots are regenerated followed
by root formation (Suprasanna et al. 2010). Regenerated plants are maintained in the
greenhouse and put under the selection pressure. Similarly somatic embryogenesis of
vegetative propagated crops (banana, date palm, cassava and others) are readily induced.
The advantage of mutagen treatment to embryogenic cell suspension that chimeras are
either eliminated or dramatically reduced, and could get mutant somatic embryos which
are regenerated into plantlets. Embryogenic cells are plated on a filter paper and put on
agar solidified medium; treat cells with gamma radiation followed by transfer them on
culture medium and allow them to form somatic embryos. The treated cells can also be
put under the selection pressure in order to isolated mutants, e.g. disease, salt, drought
tolerant mutants. The selected mutant plants are transferred in the greenhouse and finally
to the field evaluation and use them for crossing with other varieties. The radiosensitive
curve should be determined to calculate LD50 dose (Lethal dose) for each experimental
plant to avoid either very high or very low dosage. Moreover, plants and even varieties
differ in radio sensitivity. Low dose of gamma radiation has promoted growth in citrus
depending of cultivar (Fig. 2), maintain embryogenic nature of date palm for 2-3 years,
promote growth in orchids, enhances secondary metabolites in medicinal plants, and used
for improving shelf life of post harvest products
A range of several mutants in different ornamental plants, maize, rice and wheat have
been isolated and used for crop breeding. Similarly LIB has been used for mutation
breeding and gene transfer. This method has many advantages such as low damage rate,
higher mutation rate and wider mutation spectrum. In rice, 11 new lines of rice mutants
with higher yield, broader disease resistance, and shorter growing period and high grain
quality were developed and now being cultivated in China. In jasmine rice from Thailand,
a wide range of mutants were recorded including short stature, red/purple colour of leaf
sheath, collar, auricles, ligules and dark brown stripes on leaf blade, dark brown seed coat
and pericarp.
Mutation induction for quality and nutrition improvement
Besides increase in yield of a crop, quality and nutrition components are equally
important in human diet. There is a necessity to enhance mineral elements (bio-
fortification) and amino acids essential for human and animals, alteration of protein and
fatty acids profiles for nutritional and health purposes, change of physicochemical
properties of starch for different end uses, enhancement of phyto-nutrients in fruits and
reduction of anti-nutrients in staple food. Induced mutations could play an important role
in inducing mutations for enhancing nutritional quality in crop plants. Of the 3000 mutant
varieties developed globally, 776 mutants (Fig. 3) have been induced for nutritional
quality (www-mvd.iaea.org).
Collaborative research programme under Food & Agriculture Organization and
International Atomic Energy Agency (FAO/IAEA) has been focussed on at crop
improvement by induced mutation using nuclear techniques (Jain 2000) intended to
produce strains of cereals with higher concentrations of micronutrients and improvement
of their bioavailability by reduction in the concentration of phytic acid. In this regard,
strategies should be aimed at breeding plants that can contain high levels of minerals and
vitamins in their edible parts to reduce substantially the recurrent costs associated with
fortification and supplementation (Shetty 2009). Such a strategy will be successful
depending on farmer’s willingness to adopt such varieties, palatability of the edible parts
of these varieties and consumer acceptability, and if the incorporated micronutrients can
be absorbed by the human body (Bouis 2002). Certain considerations need to be
addressed before a plant breeding strategy can be put in place to combat micronutrient
deficiency to function and to have universally adoptability, particularly in Developing
Countries (Bouis 2002). These include, feasibility to breed micronutrient- dense staple
food varieties, effects on plant yields and farmer’s adoption of such varieties, possibility
of changes that micronutrient density can have a great nutritional balance on the staple
diet of consumers, bioavailability of extra micronutrients in staple foods to humans, and
alternate options for more easily sustainable strategies for reducing micronutrient
malnutrition.
Several mutant genes have been successfully introduced into commercial crop varieties
that significantly enhance the nutritional value of crops like maize, barley, soybean, and
sunflower. In maize, quality protein maize (QPM) varieties are grown on hundreds of
hectare land. They have almost twice higher amount of lysine and tryptophan, and 30%
less leucine as compared to parental lines; shown a dramatic effect on human and animal
nutrition, growth and performance. In cassava, three mutants have been isolated showing
different size of starch grain. They have high economic potential for industrial use of
starch and influence on cooking quality. Small starch grain size seems to be highly
suitable for bio-ethanol production. In sweet sorghum, a mutant variety Yuantian No.1
has been developed in China (Fig. 4), which has 20% more total carbohydrates as
compared to the parental lines; well suited for Food, Feed and Bio-energy (three in one).
Five rice giant embryo mutants, characterized by enlarged embryo than that of wild type
were found to have increase in the contents of protein, vitamin B1, vitamin B2, vitamin E,
essential amino acids such as arginine, aspartic acid, glutamic acid, lysine, methionine
and mineral elements such as calcium, iron, potassium, phosphorus and zinc (Zhang et
al. 2007). In banana, several mutants have been isolated for different traits, namely
reduced height, tolerance to Fusarium wilt, early flowering, large fruit size, Black
sigatoka tolerant types (Jain, 2010b). In date palm, several mutant lines tolerant to
Bayoud disease, caused by Fusarium oxysporum f. albedinis fungus, and the plants are
already in the field for the last four years and growing well in Algeria (Jain 2007). New
mutant varieties of barley, wheat, rice and soybean with low phytic acid (LPA) have been
released and has facilitated to reduce both phosphorous pollution and increase
bioavailability of phosphorous and micronutrient minerals in cereals and legumes.
Relevance of Biotechnology and biofortification
Prasad (2010) identified three major micronutrient deficiencies in humans which include
vitamin A deficiency, iron deficiency and iodine deficiency. Micronutrient deficiency of
Zn has also received global attention (Hussain et al, 2010). In addition, improving the
content of essential amino acids in important staple foods, such as rice, has gained interest
(Welch and Graham 2004). Rice is also one of the priority crops for enhancement of the
nutritional factors such as vitamin A, Zn and iron through international schemes such as
Harvest Plus (Pfeiffer and McClafferty 2007). Increase in bioavailability of Fe in rice has
been investigated by transferring a gene for heat resistant phytase from fungal sources that
degrades phytate in plant (Bhat and Vasanthi 2005) which may also increase the Zn
bioavailability in rice.
An adequate concentration of micronutrients seems to be essentially required in major
staple crops if these crops are addressed to provide a sustainable solution to the problem
of malnutrition (Pinstrup-Anderson and Pandya- Lorch 2001). This holds true for cereals
since majority of the population in the developing world depend on cereal based food
intake. Rice alone contributes to 23% of the energy consumed worldwide and countries
that rely on rice as the main staple often consume up to 60% of their daily energy from
this cereal (Khush 2003). Conventionally, nutrient content of crops can be improved by
using field fortification strategies, to enhance the micronutrient and trace element content
of crops by applying enriched fertilizers to the soil. Biotechnological tools have generated
new opportunities to improve the amount and availability of nutrients in plant crops.
These include simple plant selection for varieties with high nutrient concentration in the
seeds, cross-breeding for incorporating a desired trait within a plant, and genetic
engineering to manipulate the nutrient content of the plant (King 2002). One of the
successful examples in using the genetic engineering approach is the production of
“Golden Rice” involving the transfer of the genes necessary for the accumulation of
Carotenoids (vitamin A precursors) in the endosperm that are not available in the rice
gene pool. The first generation Golden Rice with a gene from daffodil and a common soil
bacterium drew considerable criticism as a technological solution to a problem associated
with poverty and hunger. It was argued that Golden Rice would encourage people to rely
on a single food rather than the promotion of dietary diversification. The development of
Golden Rice 2 by replacing the daffodil gene with an equivalent gene from maize
increased the amount of beta carotene by about 20-fold resulting in about 140 grams of
the rice providing a child’s RDA for beta carotene (Raney and Pingali 2007). It has also
been recently demonstrated that beta carotene from golden rice is efficiently converted to
vitamin A in humans (Tang et al. 2009).
Neglected/underutilized crop resources for nutrition provision
Agricultural biodiversity is essential both in terms of food and nutritional security.
Diversity of kingdoms, species and gene pools can increase the productivity of farming
systems in a range of growing conditions, and more diverse farming systems are also
generally more resilient in the face of perturbations, thus enhancing food security, better
nutrition and greater health (Ochatt and Jain, 2009; Frison et al. 2011). Global food
security depends mostly on a handful of cultivated species and more than 50% of the daily
requirement of proteins and calories is derived from three major crops viz., wheat, maize
and rice (Bharucha and Pretty 2010). More than 7000 wild plant species are known to
have been used for human food at some stage in human history (Grivetti and Ogle 2000);
in India, 600 plant species are known to have food value (Rathore 2009).
In contrast, the availability of orphan- or understudied-crops as the major staple food
crops in many developing countries has contributed significantly. Some examples include,
cereals (e.g. millet, tef, fonio), legumes (cowpea, bambara groundnut, grass pea), and root
crops (cassava, yam, enset). Orphan crops are in general more adapted to the extreme soil
and climatic conditions prevalent in Africa than the major crops of the world. Minor
millets, which are high in nutrients such as calcium and iron, are grown primarily in hilly,
arid areas of India where, because of their high tolerance to drought, they are often more
productive than other grains (Tadele, 2009ab; Anon. 2010). However, due to lack of
genetic improvement, orphan crops produce inferior yield in terms of both quality and
quantity. The majority of the world’s food is produced from only a few crops, and yet
many neglected and under-utilized crops are extremely important for food production in
low income food deficit countries (LIFDCs). As the human population grows at an
alarming rate in LIFDCs, food availability has declined and is also affected due to
environmental factors, lack of improvement of local crop species, erosion of genetic
diversity and dependence on a few crop species for food supply. Neglected crops are
traditionally grown by farmers in their centres of origin or centres of diversity, where they
are still important for the subsistence of local communities, and maintained by socio-
cultural preferences and traditional uses. These crops remain inadequately characterised
and, until very recently, have been largely ignored by research and conservation.
Radiation-induced mutation techniques have successfully been used for the genetic
improvement of “major crops” and the know-how will greatly benefit genetic enhancing
of under-utilized and neglected species towards their domestication and crop
improvement. Realizing such a need, the FAO/IAEA initiated a program on genetic
improvement of under-utilized and neglected species through a Coordinated Research
Project on “Genetic Improvement of Under-utilized and Neglected Crops in LIFDCs
through Irradiation and Related Techniques” in 1998. The overall objective was to
improve food security, enhance nutritional balance, and promote sustainable agriculture in
LIFDCs (IAEA-TECHDOC.1426, 2004, Jain, 2009). The species that were studied
included medicinal and aromatic plants that are important for the West Asia and North
Africa [e.g. argel (Solenostemma arghel), caper (Capparis spp.), oregano (Origanum
syriacum), mint (Mentha piperita), liquorice (Glycyrrhiza glabra), aloe (Aloe spp.),
coriander (Coriandrum sativum), cumin (Cuminum cyminum) and henna (Lawsonia
inermis)], Andean grains for Latin America [e.g. quinoa (Chenopodium quinoa), canihua
(C. pallidicaule) and amaranth (Amaranthus caudatus)] and nutritious millets for Asia
[e.g. finger millet (Eleusine coracana), Italian millet (Setaria italica) and little millet
(Panicum miliare)] (Jain, 2009).
Reverse and forward genetics
The new gene discovery with reverse and forward genetics will open the way for
developing functional genomics plant breeding. The general strategy for reverse genetics
is called TILLING (Targeting Induced Local Lesions in Genomics) or coming together
with traditional mutagenesis functional genomics (Gilchrist and Haughn, 2005; Tadele et
al 2010). TILLING allows the identification of single-base-pair allelic variation in a target
gene in a high-throughput manner. Furthermore DNA sequence information of mutants or
crop plants facilitate the isolation of cisgenes, which are genes from crop plants
themselves or from crossable species (Jacobsen and Schouten 2010). The increasing
numbers of these isolated genes provide an opportunity to improve plant breeding while
remaining within the gene pool of the classical breeder or mutation breeder.
Finally, a multiple disciplinary approach would be ideal by including conventional and
mutation breeding together with the molecular tools for developing new crop varieties
with high yield with improved nutritional qualities in sustaining food and nutritional
security worldwide.
Conclusion
Nutrition security is integral to food security. Induced mutations are significant as novel
mutations are being isolated for enhanced nutrition quality of crop plants, for ex.
micronutrients, protein, amino acids, fatty acids and vitamins. Another source of nutrition
provision is from the neglected and underutilized crops, and requires more attention
together with the major crops for enhancing nutrition provision to the ever-growing
human population. Perhaps change of food habits would be required gradually move away
from the consumption of major crops and start using underutilized crops either singly or
in combination of both. Developing genetically novel germplasm with increased content
of these together with other health benefit components becomes more feasible concurrent
with the enhancement of breeding techniques, genomics, molecular manipulations and
genetic engineering. The cost effectiveness of applying new technologies and trained
manpower would be of paramount importance for nutrition provision to the low cost
nations.
References
Anon. 2010. Bioversity International: Unlocking the potential of minor millets.
http://www.bioversityinternational.org/nc/announcements/unlocking
the_potential_of_minor_millets. 18 October 2010.
Bharucha, Z. and Jules Pretty 2010. The roles and values of wild foods in agricultural
systems. Phil. Trans. R. Soc. B 27 September 2010 vol. 365 no. 1554 2913-2926
Bhat, R. V. and S.Vasanthi. 2005. Food safety assessment issues of transgenic rice in the
Indian context. In Biosafety of Transgenic Rice (eds Chopra, V. L., Shanthanam, S. and
Sharma, R. P.), National Academy of Agricultural Sciences, New Delhi, , pp. 65–74.
Bouis, H.E. 2002. The role of biotechnology for food consumers in developing countries.
In: Qaim M, Krattiger A, von Braun J (eds) Agricultural biotechnology in developing
countries: towards optimizing the benefits for the poor. Kluwer Academic, USA
Frison, EA., Cherfas, J. and Hodgkin T. 2011. Agricultural Biodiversity Is Essential for
a Sustainable Improvement in Food and Nutrition Security. Sustainability 3: 238-253
Gilchrist, E. J. and G.W. Haughn. 2005. TILLING without a plough: a new method with
applications for reverse genetics. Curr. Opinion Plant Biol. 8:1-5.
Grivetti, L. E. and B. M. Ogle. 2000. Value of traditional foods in meeting macro- and
micronutrient needs: the wild plant connection. Nutr. Res. Rev. 13, 31–46.
Hussain, S., M. A. Maqsood, and Rahmatullah 2010. Increasing grain zinc and yield of
wheat for the developing world: a review. Emir. J. Food Agric. 22:326-339.
IAEA-TECDOC- 1426. 2004. Genetic improvement of underutilized and neglected crops
in LIFDCs through irradiation and related techniques”, Vienna, Austria
Jacobsen, E. and H.J. Schouten. 2010. Cisgenesis- next step in classical plant breeding.
In: Molecular techniques in crop improvement. S.M. Jain and D.S. Brar (eds.),
Springer, pp 591-611.
Jain, S. M. 2000. Mechanisms of spontaneous and induced mutations in plants. In:
Moriarty M, Mothersill C, Seymour C, Edington M, Ward JF, Fry RJM (eds) Radiation
research, vol 2. International Association for Radiation Research, Lawrence, pp 255–
258
Jain, S.M. 2007. Recent advances in date palm tissue culture and mutagenesis. Acta Hort.
736: 205-211.
Jain, S.M. 2009. Mutation induced genetic improvement of neglected crops. In:
International Conference on ‘New Approaches to Orphan Crops Improvement in
Africa’ to be held from 19 to 21 September 2007 in Bern, Switzerland. Pp 115-126.
Jain, S.M. 2010a. Mutagenesis in crop improvement under the climate change. Romania
Biotech. Letter 15(2):88-106.
Jain, S.M. 2010b. In vitro mutagenesis in banana improvement. Acta Hort. (in press).
Jain, S.M. 2011. Radiation induced mutations for date palm improvement. In: Date palm
biotechnology, S.M. Jain, J. El Khayari, and D. Johnson (eds.). Springer (in press)
Jain, S.M., J. El Khayari and D. Johnson (eds.) 2011. Date palm biotechnology, Springer
(in press).
Ochatt, S. and S.M. Jain (eds.). 2009. Breeding of neglected and under-utilized crops,
spices and herbs. Science Publishers, New Hampshire, USA
Khush, G.S. 2003. Productivity improvements in rice. Nutr Rev 61: S114–116
King, J.C. 2002. Evaluating the impact of plant biofortification on human nutrition. J Nutr
132:511S–513S
Kharkwal, M.C. and Q. Y. Shu. 2010. The role of induced mutations in world food
security. Q.Y. Shu (ed.), Induced Plant Mutations in the Genomics Era. Food and
Agriculture Organization of the United Nations, Rome, 2009, 33-38
Pfeiffer, W. H. and B. McClafferty. 2007. HarvestPlus: breeding crops for better nutrition.
Crop Sci. 47, S88–S105.
Pinstrup-Anderson, P. and R. Pandya-Lorch. 2001. Who will be fed in the 21st century?
Solutions and action. In: Wiebe K, Ballenger N, Pinstrup-Andersen P (eds.) Who will
be fed in the 21st century? Challenges for science and policy. IFPRI, Washington
Prasad, R. 2010. Zinc biofortification of food grains in relation to food security and
alleviation of zinc malnutrition. Curr. Sci. 98: 1300-1304.
Ramakrishnan, U. 2002. Prevalence of micronutrient malnutrition worldwide. Nutrition
Reviews 60: S46-52
Raney, T. and P. Pingali. 2007. Sowing a gene revolution. Sci. Am. 297:104–107
Rathore, M. 2009 Nutrient content of important fruit trees from arid zone of Rajasthan. J.
Hort. Forestry 1:103–108.
Shetty, P. 2009. Incorporating nutritional considerations when addressing food insecurity.
Food Sec. 1:431–440
Shu, Q.Y. 2010. Induced plant mutations in genomics era. Food and Agriculture
Organization, Rome.
Suprasanna, P., Jain, S.M., Ochatt, S.J., Kulkarni, V.M. and Predieri, S. 2010.
Applications of in vitro Techniques in Mutation Breeding of Vegetatively Propagated
Crops. Plant Mutation. Ed. Q. Shu. IAEA, Vienna pp 369-383.
Tadele, Z. 2009a. Role of orphan crops in enhancing and diversifying food production in
Africa. Afr. Techol. Develop. Forum Jour. 6(3/4): 9-15
Tadele, Z (ed.). 2009b. New Approaches to Orphan Crops Improvement in Africa. Proc.
Intern. Conf.., 19-21 September 2007, Bern Switzerland. ISBN: 978-3-033-02012-2.
Tadele, Z., M.B.A. Chikelu, and B.J. Till. 2010. TILLING for mutations in model plants
and crops. In: Molecular techniques in crop improvement. S.M. Jain and D.S. Brar
(eds.), Springer, pp 307-332.
Tang, G., J. Quin, G. G. Dolnikowski, R.M. Russell and M. A. Grusak. 2009. Golden rice
is an effective source of vitamin A. Am. J. Clin. Nutr. 89:1776–1783
Welch, R.M.; Graham, R.D. 2004. Breeding for micronutrients in staple food crops from
a human nutrition perspective. J. Exp. Bot. 55: 353-364.
Zhang, L., X. L. Shu, X. Y. Wang, H. J. Lu, Q. Y. Shu and D. X. Wu. 2007.
Characterization of indica-type giant embryo mutant rice enriched with nutritional
components. Cereal Res. Comm. 35: 1459-1468.
Table 1. Some of the major orphan crops of Africa having important nutritional
characteristics. (modified after Tadele, 2009)
Common
Name
Botanical name Important trait
African
eggplant
Solanum aethiopicum High yielding
African yam
bean
Sphenostylis stenocarpa High protein content
Amaranth Amaranthus spp. Fast growing
Bambara
groundnut
Vigna subterranea Rich in protein,
drought tolerant
Barbados
cherry
Malpighia glabra Rich in vitamin
Cassava Manihot esculentum Drought tolerant
Chickpea Cicer arietinum Protein source
Dika Irvingia gabonensis, I .
wombolu
oil-rich
Finger millet Eleusine coracana Rich in iron, protein;
low in glycaemic
index
Fonio Digitaria exilis Fast maturing
Noug Guizotia abyssinica High oil content
Quinoa Chenopodium quinoa High in
protein content
Sesame Sesamum indicum oxidatively stable oil
Sweet potato Ipomoea batatas rich in riboflavin and
calcium
Tef Eragrostis tef Tolerant to abiotic
stresses; free of gluten
Vernonia Vernonia galamensis High oil content
Figure 1. Global prevalence of micronutrient malnutrition* (Ramakrishnan 2002)
*For more details, please refer Ramakrishnan (2002)
Figure 2: Differential response of citrus varieties to different doses of gamma radiation
treatment. Citrus var. Losslille is more radiation tolerant when compared to two other
varieties: 30 Gy dose promotes shoot growth, which is much better than the control as well as
other two varieties.
Radiation dose effect on
citrus
Figure 3. Global mutant varieties with nutritional quality and other desirable attributes (based on the data from www-mvd.iaea.org; September 2010)
Figure 4: A new sweet sorghum mutant variety, which is suitable for food, feed, and bio-
energy
New Sweet Sorghum Mutant Variety Yuantian No.1