摘要
Sexual reproduction of flowering plants depends on the delivery of two immotile sperm cells to the female gametophyte(FG),i.e.the embryo sac,through the growth of a pollen tube,a long cylindrical cellular extension from a pollen grain.The journey of pollen tubes toward the embryo sacs is led by female cues,which guide the path of the pollen tubes.Recognition between the male-female gametophytes in some cases precedes successful
Sexual reproduction of flowering plants depends on the delivery of two immotile sperm cells to the female gametophyte（FG）,i.e.the embryo sac,through the growth of a pollen tube,a long cylindrical cellular extension from a pollen grain.The journey of pollen tubes toward the embryo sacs is led by female cues,which guide the path of the pollen tubes.
