6Schulz P,Jensen W A.Pre-Fertilization Ovule Development in Capsella:Ultrastucture and Ultracytochemical Localization of Acid Phosphatase in the Meiocyte[J].Protoplasma,1981,107:27-45.
7Jane W N,chiang S H.Ultrastructure of megasporogenesis and early megasporogenesis in Arundo[J].int J Plant Sci,1996,157:418-431.