marble tile
 

i have a stair riser going into kitchen i had marble tile there but it didn`t stick i did not put backerboard on becauce it would cause ithe riser piece stick out further than the tred. how can i get the ti;le to stick to the wood substrate??

Not a good idea. Not only is wood not a good substrate for tile, any movement will cause tiles to come off (like you've experienced).