Plants continue to provide us food, shelter and clothing as well as other useful items. Xow , the problem of food production is acute and will become more critical with each passing year.
Although, the world is increasing its food supply, population growth is now outstripping food production in developing countries like India. The population explosion of the last few decades has given rise to a situation causing people, mostly children, to die each day from hunger, malnutrition and related diseases.
We need to increase food supply that will involve many different approaches like (l) bringing more land under cultivation and (2) introduction of modern agricultural technology.
The approach No.(i) has severe limitations while the approach No.(2) gives us enormous scope. Further, with, improved technology what we require is ‘crop improvement’ with seeds having better genetic make-up to yield more, to grow under varied climatic conditions and to be resistant to diseases. Here comes the role of Plant Breeding which aims to evolve improved plant varieties with good qualities in them and also superior to existing varieties in many aspects.
The techniques of plant breeding have evolved from simple methods of the remote past to the present in the form of –
1. Selection 2. Hybridisation 3. Introduction 4. Mutation Breeding 5 .Breeding for disease resistance.
This is a time-honoured method of selecting a continuous autonomous process which is in fhnenced by natural factors.
This refers to crossing of two genetically different individuals. In all crossing programmes the aim is to combine the desirable characters of two or more varieties, germ plasm lines or species.
This refers to the introduction of plants for the purpose of using them as donors of genes for the improvement of existing genotype that are dificient in one or a few superior qualities.
4. Mutation Breeding:
This is exploiting the accurrance of variations through mutations (natural or induced) seen in different crop plants for the purpose of breeding.
5. Breeding for disease resistance:
This rerers to the techniques adopted to infuse genes that are resistance to diseases occurring in any area where susceptible crops grow. The aim is to produce crop varieties that may resist the occurrance of prevalent diseases in a particular area.