Crosses between two plants by the same variety are called Intravarietal.

Intravarietal crosses refer to the breeding or crossing of plants within the same variety. When two plants that belong to the same variety are crossed, the resulting offspring will also be of the same variety. This type of crossing is often carried out to enhance specific traits or characteristics within a particular variety.

Explanation:

1. Definition of Intravarietal crosses:
- Intravarietal crosses involve the breeding of plants within the same variety.
- A variety is a subdivision of a species that has distinct characteristics and is recognized as a separate entity.
- When two plants of the same variety are crossed, the resulting offspring will also belong to the same variety.

2. Purpose of Intravarietal crosses:
- Intravarietal crosses are carried out to enhance specific traits or characteristics within a particular variety.
- By selectively breeding plants within the same variety, breeders aim to produce offspring with desirable traits such as improved yield, disease resistance, or better quality.
- This type of crossing allows for the preservation and improvement of existing varieties.

3. Examples of Intravarietal crosses:
- One example of an intravarietal cross is the crossing of two tomato plants of the same variety that exhibit desirable traits such as large fruit size and resistance to a particular disease. The resulting offspring will also possess these traits.
- Another example is the crossing of two rice plants of the same variety that have high yield potential. The goal is to produce offspring with even higher yield potential.

4. Importance of Intravarietal crosses:
- Intravarietal crosses play a crucial role in crop improvement and variety development.
- By selectively breeding within a variety, breeders can enhance desirable traits while maintaining the overall characteristics of the variety.
- This allows for the development of improved varieties that meet the specific needs of farmers, consumers, and the agricultural industry as a whole.

In conclusion, crosses between two plants of the same variety are called intravarietal crosses. This type of crossing is important for crop improvement and variety development, as it allows for the enhancement of desirable traits within a particular variety while maintaining its overall characteristics.