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.
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.
Increase in population has forced us to carry out continuous scientific experiments for the following reasons viz.
1. To develop more food crops.
2. For increase quality in food crops.
3. To have sustainable food quality in food crops and assured food
By introducing specialized technology, plant breeder are now able
to develop more crops, which they multiply and supply them to the growers. Improvement in the genetic make up of plants is called plant breeding.
Major aspects of plant breeding include
1. creation of useful variation in the cultivable crops.
2. selection of better crops.
3. conducting / carrying out breeding experiments to assess the quality of the crop and
4. release of a variety after their extensive multiplication.
Plant physiology – photosynthesis and its significance
Aspects of plant breeding and Types
Hybridization in plant breeding
Polyploid breeding, Mutation breeding, Breeding for disease resistance
Genetic engineering, Improved varieties, Role of biofertilizers
Green manuring, Mycorrhiza as biofertilizer
Crop diseases and their control, Rice – Oryza sativa
Groundnut or peanut – Arachis hypogea
Citrus canker, Tungro disease of rice
Biocontrol of insect pests Bacterial pesticides
Bio war, Genetically Modified Organisms (GMO) in biological warfare
Biopiracy, Bioresources, Biomolecules, Biopatent, Biotechnology
Medicinal plants including microbes
Commonly Available Medicinal Plants
Economic importance of Food plant Rice
Oil plant Groundnut Economic importance
Fibre plant – Cotton Economic importance
Timber yielding plant Teak Economic importance