A, ① is grafting, which belongs to a vegetative propagation mode of asexual propagation. When grafting, the scion should be closely combined with the cambium of rootstock to ensure the survival of the scion. Grafted branches or buds are called scions, and grafted plants are called rootstocks. A is correct.

B, ② refers to tissue culture, which refers to the technique of cutting the stem tips, stem segments and leaves of plants into small pieces under aseptic conditions, culturing them on special culture medium, and gradually developing into complete plants through cell proliferation and differentiation. Using this technology, a large number of new individuals of plants can be cultivated in a short time, and the reproduction speed is very fast, and the excellent characteristics of parents can be maintained. B correct.

C, ① Grafting, ② Tissue culture belongs to asexual reproduction, ③ Seed reproduction belongs to sexual reproduction, and C is correct.

D, ③ Seeds develop from ovules, and fertilized eggs develop into embryos. D is wrong.

So choose: D.