Genesis of microspore, megaspore and the development of male gametophyte, female gametophyte in Diphylleia sinensis A KARYOTYPIC STUDY ON PODOPHYLLOIDEAE (BERBERIDACEAE) Study on the seed weight and seed seize variation pattern and their biological sinificance in Podophylloideae (Berberidaceae) A contribution to the reproductive biology of Diphylleia sinensis (Berberidaceae) in Zhongdian,Yunnan province