All the properties of propertygrid and its dependent properties can be declared in 'data-options' attribute. To add a new row to propertygrid, call 'appendRow' or 'insertRow' methods. If the 'showGroup' property is set to true, be sure to re-group rows again. The code below shows how to append a new row to a specified group.
var pg = $('#pg');
pg.propertygrid('appendRow',{name:'n11',value:'v12',editor:'text',group:'ID Settings'});
var data = pg.propertygrid('getData');
pg.propertygrid('loadData', data);