如何使选择元素在Chrome中透明？

select {

  width:192px;  padding:2px;  border:none;  background:url(http://imgur.com/MJyZM.png) 0 0 no-repeat;  -webkit-appearance: none;}<select>  <option value="abcdefg">abcdefg</option>  <option value="1234567">1234567</option>  <option value="abcdefg">abcdefg</option></select>

尚未在Firefox上进行测试，但似乎

-webkit-appearance: none;