Sucker branch?

Hi,

Is this a sucker shoot/ branch on this potted orange tree ? Also, it has some weird browniing of the leaves !
Thanks

 

It doesn't look like a grafted plant, so my guess is its not really a suckere, just a new branch forming.
Not sure what has caused the browning of the older leaves.

 

Thanks Pete . Ah ok, I’m not sure if it’s grafted , it’s from an online garden shop . Is there any way to tell if it’s grafted ? I’ll send a closer picture of the browning. Looks like something’s been eating it and caused a webbing and then brown dry patches

 

Usually if its grafted there is a definite lump at some point on the stem, and usually there is a clear length of stem.
I think you might have a cutting.

The browning on the leaf sounds like some kind moth damage from last year.