Which statement is incorrect about linkage-

Options

A. It helps in maintaining the value traits of new varieties
B. It helps in forming new recombinants
C. Knowledge of linkage helps to breeder to combine all desirable traits in a single variety.
D. It helps in locating genes on chromosome

Answer

To determine which statement is incorrect about linkage, let's analyze each option step by step:

1. **Understanding Linkage**: Linkage refers to the tendency of alleles that are located close together on a chromosome to be inherited together during meiosis (the process of cell division that produces gametes). This is because genes that are close to each other are less likely to be separated during crossing over.

2. **Analyzing the Statements**:
- **Statement 1**: "It helps in maintaining the value traits of new varieties."
- This statement is correct. Linkage can help maintain desirable traits in new plant or animal varieties by ensuring that beneficial alleles are inherited together.

- **Statement 2**: "It helps in forming new recombinants."
- This statement is incorrect. Linkage actually reduces the formation of new recombinants because genes that are closely linked are less likely to be separated during crossing over. Therefore, the presence of linkage leads to fewer recombinants.

- **Statement 3**: "Knowledge of linkage helps the breeder to combine all desirable traits in a single variety."
- This statement is correct. Understanding linkage allows breeders to select for traits that are inherited together, thus facilitating the combination of desirable traits.

- **Statement 4**: "It helps in locating genes on chromosomes."
- This statement is also correct. Linkage analysis is a method used to determine the relative positions of genes on chromosomes.

3. **Conclusion**: The incorrect statement about linkage is that "it helps in forming new recombinants." This is because linkage decreases the likelihood of recombination between linked genes.

### Final Answer:
The incorrect statement about linkage is: "It helps in forming new recombinants."