Assertion : Agrobacterium tumefaciens is popular in genetic engineering because this bacterium is associated with the roots of all cereal and pulse crops. Reason : A gene incorporated in the bacterial mesosome gets automatically transferred to the crop with which the bacterium is associated.

Step-by-step solution

( Agrobacterium tumefaciens causes crown gall disease on a wide range of dicot (broad leaved) plants especially members of rose family by transferring its own DNA into plant cells. But in laboratory, the ability to move all sorts of genes into plants has made the microbe the standard tool for investigating plant genetics and modifying crops.