Biotechnology for crop Improvement
G. Sabari nathan
Using the techniques of biotechnology, one or two genes may be transferred to
a highly developed crop variety to impart a new character that would increase its yield. There
are, broadly, three benefits to agriculture and crop-improvement programmes from use of
biotechnology. The first of these, the reduction of the duration of breeding programmes, makes
use of tissue culture. Plant tissue culture also allows creation of new genetic variation, from
which useful new varieties can be obtained. New methods of hybridization can be combined with
cell and tissue culture for selection of plants with desired traits. The third and most promising
benefit is from use of recombinant-DNA techniques. Transgenic plants, engineered for resistance
to diseases, pests and herbicides, and for better nutritional quality.
Functional genomics, Genetic engineering, Marker-assisted breeding
(MAS),Tolerance to abiotic stresses, Durable host-plant resistance, enhancing nutritional quality,
Nitrogen fixation in rice and Apomixis for hybrid seeds these are some of the biotechnology
tools for improving crop productivity and stability of production.
Abiotic stress is the most harmful factor concerning the growth and productivity of crops.
Abiotic stress can be overcome by transferring stress-induced genes to the crops. Some of the
genes responsible for exhibiting resistance to abiotic stress are as follows;
Heavy metal stress:
Divalent cation tolerance protein
GENES ISOLATED FROM MANGROVES
Drought and Anaerobic:
Protein disulfide isomerase
Super oxide dismutase(SOD)
Strategies to overcome abiotic stresses
Conventional plant breeding techniques have been used to develop new varieties able to produce
greater yields in spite of abiotic stresses.
The potential of biotechnology
In spite of the explosive development of biotechnology in the last 20 years, its use for obtaining
new abiotic stress
tolerant varieties has been very limited. The lack of basic scientific informa
tion of the molecular biology of crops is certainly the greatest constraint to the use of biotechnol
ogy for stress tolerance. Abiotic stress tolerance is the result of many genes expressed simultane
ously or in a certain order. Often this expression concerns plant architecture (roots, length of the
plant, leaf configuration) and complex physiological responses controlled by groups of genes. In
contrast to resistance to pests and insects, which can be obtained through modification of quite a
few genes, these traits will be much more difficult to modify. Modification of a complex of
genes is still beyond the possibilities of the current genetic engineering and transformation tech
nologies. But most important, very little is known about the molecular basis of important physio
logical and biochemical responses and characteristics of plants and animals.
Even if it is still early to expect biotechnology to contribute to practical production problems in
the area of stress tolerance, it is definitely making a great contribution to the understanding of the
plant physiology and biochemistry on the molecular and genetic level. Genetic engineering and
other biotechniques are being widely used to study the mechanisms responsible for stress toler
ance. This basic scientific research concentrates worldwide on drought, salinity and temperature
responses of plants on the molecular level.
MSSRF’s Anticipatory Research Programmes:
These programmes aims at developing location specific crop varieties offering resistance to
coastal salinity through identification of novel genetic combinations from the salt tolerant
mangrove species, generation of pre breeding material and integration of pre- and participatory
Delivering the lead talk on ''Ensuring and Enhancing Crop Productivity in
Response to Emerging abiotic Stress Conditions'' in the plenary session on ''Biotechnology'' at
the 97th edition of the Indian Science Congress, Dr Ajay Parida, Executive Director, M S Swami
Nathan Research Foundation (MSSRF) said India’s population is likely to reach 1.5 billion by
2030. There will be no option except to produce more and more from Diminishing per capita
arable land and irrigation water Resources and expanding abiotic and biotic stresses. We need to
double the food production, from the present 210 million tones to 420 million tones, within the
next 10 years. This will call for accelerated scientific efforts in the field of enhancing
productivity per unit of water, in coastal and inland areas under conditions of both water scarcity
and water salinity.
Dr Parida said the presence of salt content in soil increased because of over exploitation
of ground water, particularly in Punjab and Haryana. The MSSRF foundation had developed two
paddy seeds suitable to survive the salt and drought conditions by implanting the gene of
'Abrinna Marins'', a variety of mangrove and ''Abrinna Marins Ferrilian'', a plant found in
deserts, respectively. Outlining the challenges facing Indian agriculture like loss of cultivable
land, decline in water resources, loss of bio-diversity and forests, climate change and invasion of
trans-boundary pests; he said biotechnology could be an answer to them.
Appropriate targets for crop improvement:
Abiotic stress resistance
Integrated pest management
Integrated nutrient management
Enhanced resource utilization
Integrated natural resource management Systems
Biotechnology and Molecular Breeding.