BOTANY Higher Secondary Second Year - Textbooks Online

6. BIOLOGY IN HUMAN WELFARE
The world’s human population, which was only one billion during
1850, had reached 6.1 billion around year 2000. This dramatic increase
in population, otherwise called ‘population explosion’ has created its impact
not only on the environment but also on food production.
Half of this 6.1 billion people live in poverty and one fifth of this
population suffer due to malnutrition. Increase in population, unplanned
industrialization and migration towards cities and urban areas has resulted
in the degradation of the environment. The present agricultural practices
have polluted cultivable land physically, chemically and biologically. The
net productivity is gradually being reduced. These factors lead to the
shrinkage of the agricultural lands and a fall in agricultural production.
6.1. Food production
In order to fight the menace of hunger and malnutrition, we need
crops with greater yield and better nutritive value. The quantity and
quality of crops can be improved by modern scientific methods through
genetic manipulation called genetic engineering. However, the time old
concept of breeding plants either interspecific or intraspecific to bring out
the best hybrid plant in plant breeding programmes still remains in vogue
even today. Efforts are being made by ICAR – Indian Council of
Agricultural Research and other related organisations in our country to
increase food production.
A plant breeder strives to get a group of plants or a variety with
suitable combination of genes that gives better yield and improved quality
under a particular set of environmental conditions. A single species is a
group of assemblage of innumerable number of genetic types such as
lines, strains, etc. The strains are tested in various climatic conditions,
successful ones are named, multiplied and distributed as a variety or cultivar
eg. Oryza sativa Co.15, ADT. 16.
Breeding experiments
Increase in population has forced us to carry out continuous scientific
experiments for the following reasons viz.
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