Question about "Dedicated to FortiSwitch" port option.

[train_wreck]

I have a Fortigate 30E.It has ports 1 - 3 configured as 3 separate LANs, with the Fortigate taking the .1 IP address in each respective LAN. If I add a Fortiswitch, can I configure port 4 of the Fortigate as "Dedicated to FortiSwitch", and then have each LAN assigned to a particular VLAN that is trunked to the Fortiswitch?

Right now, each LAN is cabled separately from the Fortigate to a Netgear switch (soon to need replacing), and each corresponding port on the Netgear is assigned to a respective access (untagged) VLAN. I'd like to eliminate the cabling if possible.