SFP+ Auto negotiation to SFP

I would like to know if i conect a fortiswitch with an interface SFP+ (10GB) to another Fortiswitch with an interface SFP (1GB), this conection will work ? can auto negotite the speed to 1GB ??? 

I found this on the administration guide 

¨Auto-module speed detection

When you enable auto-module speed detection, the system reads information from the module and sets the port speed to the maximum speed that is advertised by the module. 

NOTE: Auto-speed detection is supported on 1/10G ports¨

But i read in a KB that no all fortiswich serie support autonegotiation. 

Can some have test it ? 

FortiSwitch