The Arabidopsis Anaphase-Promoting Complex/Cyclosome Subunit 1 is Critical for Both Female Gametogenesis and Embryogenesis Four Closely-related RING-type E3 Ligases, APD1–4, are Involved in Pollen Mitosis II Regulation in Arabidopsis STUDIES ON MICROSPOROGENESIS AND DEVELOPMENT OF MALE GAMETOPHYTE OF ALANGIUM CHINENSE (LOUR. ) HARMS Megasporogenesis,Microsporogenesis and Development of Female and Male Gametophyte of Tricyrtis maculata (D.Don) Machride