A, ① Grafting. Grafting refers to grafting buds or branches of one plant to another plant, so that the combined two parts grow into a complete plant. Grafted buds or branches are called scions, and grafted plants are called rootstocks. When grafting, the cambium of scion and rootstock should be closely combined to ensure survival. It can be seen that grafting belongs to artificial asexual reproduction, which is asexual reproduction, and A is correct;

B, ② refers to tissue culture. Tissue culture refers to the separation of some organs or tissues from plants under aseptic conditions, such as stem tip, bud tip, cambium, root tip, germ and pith tissue, and then culture in suitable culture medium. After a period of growth and differentiation, it finally grew into a complete plant. Tissue culture and propagation are very fast. It belongs to asexual reproduction, and B is correct;

C and ③ are sexual reproduction. When the seeds germinate, the radicle grows long, and the radicle first breaks through the seed coat and develops into the root of the plant. C is correct;

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

Therefore, choose: d.