Thank you LorettaNJ...
It happens to be that mutation such as variegation is not something that is too rare in nature, especially with plant with lots of seeds like Rubus, but most of these mutants are weak, without our help most of them cannot compete with normal plant in the garden, eventually they will just die.
I have just found that one of my Rubus is gone due to neglect, it can also produce fully yellow leaf. I should try to sow many and many of this species again, if I get lucky, might encounter another mutant. Here it is, a Rubus moluccanus, but this photo was an old photo, I cant found it's albino leaf photo
