I find the solution you just need to change
<telerik:GridBoundColumn DataField="ShortDescription" FilterControlAltText="Filter ShortDescription column" HeaderText="ShortDescription" SortExpression="ShortDescription" UniqueName="ShortDescription">
</telerik:GridBoundColumn>
to GridHTMLEditorColumn
<telerik:GridHTMLEditorColumn DataField="ShortDescription" FilterControlAltText="Filter ShortDescription column" HeaderText="ShortDescription" SortExpression="ShortDescription" UniqueName="ShortDescription">
</telerik:GridHTMLEditorColumn>