Concept of multiline varieties was given by Jenson.
Concept of clean crop approach and dirty crop approach was given by Marshall.
Multilines have been recognized in mid-America since at least 1898.
Borlaug recommended having a minimum of 8 to 10 lines, meaning 8 to 10 backcrossing programs would be necessary, and screening for genes resistant to a specific race, which is quite costly.
Marshall presented two methods for multiline development – the clean crop method and the dirty crop method.
Dirty multilines are a mixture of lines each with a unique resistance gene, while clean multi lines are mixtures of lines that are all resistant to the prevalent races of the disease.
Advantages of multiline varieties
- Multiline varieties can utilize horizontal resistance, which is otherwise challenging to achieve due to its genetic complexity.
- Multiline varieties tend to live longer than pure stands as a result of stabilized selection.
- All component lines are phenotypically similar, with the only difference being their resistance gene.
Difference between clean crop and dirty crop approach
Clean crop approach of multiline varieties
In the clean crop approach, all component lines of the mixture are resistant to all the prevalent races of the pathogen to be controlled.
Dirty crop approach of multiline varieties
In the dirty crop approach, each line of the mixture carries a different single gene for resistance however none of the lines are resistant to all the known races of the pathogen.
Concept of multiline varieties was given by?
Jenson gave the concept of multiline varieties.
Concept of clean crop and dirty crop multiline approach was given by?
The concept of clean crop multiline approach and dirty crop multiline approach was given by Marshall.
Difference between vertical and horizontal resistance plant breeding Link