Pruning new branches low down on Robinia

Hi, newbie here. I have a newly potted robinia ‘twisted baby’. In the last fortnight or so new branches have begun rapidly sprouting from low down on the trunk. I have read conflicting advice online and am unsure wether these should be removed or not. Any advice please?

 

Yeah cut them off, they are from the root stock.
The leaves are the true Robinia leaves, your plant is grafted on the top of a robinia root and stem, forming a standard.

 

Ok thanks for your help.