Advantages of MAB: Cost
Depending on the trait, the use of MAB can also reduce costs. Maintaining field plots and greenhouse space, and employing labour to measure traits can be expensive, and sometimes (for example certain diseases), impossible. The ability to test for the presence of a certain allele when the plant is still small rather than waiting until the associated trait can be seen can decrease the amount of phenotyping that is necessary.
Products such as the FTA cards (http://www.whatman.com) shown at left can make DNA extractions, and therefore marker work, easier. This person is extracting DNA using a very simple procedure and a very young plant.
Of course, some phenotyping will always be required to confirm results, but MAB can decrease the amount of phenotyping in many situations.