Question

Write a short note on mass selection

Answer 1

Hint: Mass selection and pure line selection are genetic breeding methods. Genetic breeding is a way to develop genetically modified crops that are disease-resistant and have better crop quality and higher yields with desirable characteristics.

Complete answer:
Mass selection is one of the most important methods used in the breeding of plants. This is the type of breeding method used for self-pollinated plants. In this method, a large population of plants is selected. The plants are cultivated and the seeds are harvested. The seeds are mixed and the varieties are mixed.

Plants from this group are selected and used for self-pollination or cross-pollination. There are two types of methods used for mass selection, Hallet and Rimpar. Environmental conditions, water and fertilizers are the characteristics that are controlled by these experiments.
There are two types of mass selection, namely:
1. Positive mass selection , and
2. Negative mass selection

1. Positive mass selection :
When desirable plants are selected from a mixed population and their seeds are mixed together for further generation, this is referred to as positive mass selection. This process has been going on for several years.Generally, old varieties or soil races are used as the base material for mass selection. Selection of desirable plants or positive approach is commonly used for mass selection.

2. Negative mass selection:
When only undesirable off-type plants are removed from the field and the rest is allowed to grow further, it is known as negative mass selection. This is generally used for varietal purification in seed production and certification programmes. This helps to maintain a high level of genetic purity in varieties, particularly in self-pollinated species.

Note: The success of mass selection depends mainly on three factors:
(i) Variability in the base population;
(ii) Mode of character inheritance to be improved, and
(iii) the heritage of the character.
(iv) In old, heterogeneous varieties or soil races, mass selection is more effective than in improved varieties.