You can connect to MQ using a JCA or JMS binding for a composite service. First step is to configure the AS to connect to IBM MQ in the first place. There are a number of threads on the AS forums which cover that subject, for example:
Is it possible to create a JCA binding directly connect to IBM MQ?
As Keith pointed out, if there is a IBM MQ JCA 1.5 resource adapter that you can deploy in the JBoss server then you'll be able to use the JCA adapter to connect to it.
It is a matter of:
1) Configure the JBoss AS to use the resource adapter
2) Create an application with a JCA binding using that resource adapter