i can bind the dropdownlist in the edit item template. The drop down list is having null values.

protected void grdDevelopment_RowDataBound(object sender, GridViewRowEventArgs e) 
{   
  DropDownList drpBuildServers = new DropDownList();

  if (grdDevelopment.EditIndex == e.Row.RowIndex)    
  {        
      drpBuildServers = (DropDownList)e.Row.Cells[0].FindControl("ddlBuildServers");    
  }
}

also getting an error

Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.