Name the methods by which the desirable qualities are incorporated into plants to improve the variety.

Hint: Plant breeding is considered as a branch of science that involves methods of changing the traits of plants in order to produce the desired characteristics. Plant breeding is exactly the focused manipulation of various plant species in order to produce desired phenotypes and genotypes for specific traits.

Complete answer:
Plant breeding includes various methods to improve food crop production. It helps in the production of crop plants having desired traits like disease resistant, high yields, quality product and response to fertilizers. Through plant breeding techniques, different strains of food crops with desirable traits can be created naturally as well as scientifically. The main purpose of plant breeding is to produce crop varieties that enhance unique and superior traits for a variety of agricultural applications. It supports sustainable agriculture to meet the needs of a growing population – not only food for humans, but also feed for animals, fuel and fibres.

Plant breeding can be performed through many different methods that range from simply selecting plants with desirable traits for propagation, to the methods that make use of knowledge of genetics and chromosomes, to more complex molecular techniques. It is practiced worldwide by many practitioners such as gardeners and farmers, scientists and professional plant breeders. It is believed by various International research agencies that producing new crops through breeding techniques is important for ensuring food security by developing new varieties that are disease resistant, higher yielding, drought tolerant or regionally adapted to different environments and growing conditions.

Note:
Plant breeding is defined as a technique of manipulation of plant species, in order to create desired plant types that are better adapted for cultivation, produce better yields and are disease resistant. It helps us to produce more with less, improving resource-use efficiency and reducing pressure on the environment.