$Agrobacterium$ $tumefaciens$ is popular in genetic engineering because this bacterium is associated with the roots of all cereal and pulse crops.

$Agrobacterium$ $tumefaciens$ is a gram-negative soil bacterium closely related to $Rhizobium$ that commonly infects dicot plants, causing crown gall disease. It is popular in genetic engineering because of its ability to transfer its own $T-DNA$ from its $Ti$ plasmid into plant cells, making it a standard tool for plant transformation. However, the assertion is false as it is not associated with "all" cereal and pulse crops (it primarily infects dicots), and the reason is also false as the transfer involves the $Ti$ plasmid, not automatic transfer from the bacterial chromosomal genome just by association.