Endless fruit for Muslim ruler (6)
I believe the answer is:
sultan
'muslim ruler' is the definition.
(I've seen this before)
'endless fruit' is the wordplay.
'endless' means to remove the last letter.
'fruit' becomes 'sultana' (sultana is a kind of fruit).
'sultana' with its last letter taken away is 'SULTAN'.
'for' is the link.
(Other definitions for sultan that I've seen before include "Muslim ruler" , "one ruling the roost?" , "Ruler of Brunei" , "One governs" , "Chicken" .)