The Designer connects each column of the MQSeries source definition to a corresponding port in the MQ Source Qualifier. The connection from a source column to an input port in the MQ Source Qualifier is predefined. The PowerCenter Integration Service reads data from all of the message header fields in a WebSphere MQ message. You cannot delete any of the connections.
To read data from multiple WebSphere MQ message queues, you need an MQ Source Qualifier for each MQSeries source definition. You cannot join two sources with an MQ Source Qualifier in a mapping.