Cotton fiber is a unicellular hair originating from the seed epidermis. Fiber development consists of four overlapping stages: fiber initiation, fiber elongation, secondary cell wall deposition and maturation. 它是由胚珠表皮细胞发育而来的单细胞绒毛。棉纤维的发育可以分为四个明显不同但略有重叠的阶段:纤维的分化和起始、细胞伸长、次生壁合成和纤维成熟。