Final answer:
The transfer of the chymosin gene from cows into the fungus Aspergillus would least likely be considered intergeneric, unlike the other options.
Step-by-step explanation:
Intergeneric organisms are those that contain DNA from different species. In the given options, the transfer of the chymosin gene from cows into the fungus Aspergillus would least likely be considered intergeneric because both the cow and fungus belong to the same kingdom, Fungi.
On the other hand, the other options involve the transfer of genes between species from different kingdoms. For example, the transfer of a bacterial gene into rice, the transfer of the growth hormone gene from a salmon into a slower-growing salmon, and the transfer of the cry toxin gene from Bacillus thuringiensis into corn all involve DNA transfer between different kingdoms, making them intergeneric.