thank you for the answer,
photos were taken yesterday, today, there are over leaf on mango tree, they are all brown and dry.
the rootstock has no leaf, it is naked, but green, the problem is at the top of the mango tree.
I looked at the underside of the leaf with a magnifying glass, there was nothing.
( I should let it grow a few leaves of rootstock, to promote the growth of the graft and root or not? )