Hi Luis,
Thanks for using syncfusion products.
We have analyzed your query. Create
the custom striplines to draw the rectangle around the nodes.
We have prepared a simple sample based on your requirement
and please check the sample under the following location.
Sample: StripLines.zip
To know more about StripLines please refer the following UG
Link,
Link: http://help.syncfusion.com/ug/silverlight/gantt/documents/striplines.htm
Please let us know if you have any other queries.
Thank you,
Jai Ganesh S