Abstract: By the help of laser scanning confocal microscope (LSCM) and paraffin-section method, six leaf-wrinkled and dwarf plants from the hybridization of Pingyi Tiancha 〔Malus hupehensis (Pamp.) Rehd. var. pingyiensis Jiang〕 and Zhaai Shandingzi〔M. baccata ( L.) Borkh.〕 were selected as the experimental materials to make the overall observation and systematic investigation about their embryogenesis development and characteristics, and the parents were used as the contrast. The results indicated that the six leaf-wrinkled and dwarf plants could carry on the normal process of the meiosis and form the functional megaspores from which the sexual embryo sacs derived. From the full blooming day to 2 days later, the sperm cells or the pollen inclusion emerged and the fertilized eggs were partially observed in the embryo sacs of the six leaf-wrinkled and dwarf plants. The proembryos formed about 10 days after the full blooming day. There were some differences about the distributing way of the nucleolus in the specific time during the development of the sacs, and few poly-embryo sacs were observed in some of the leaf-wrinkled and dwarf plants. So, the embryogenesis characteristics of the leaf-wrinkled plants were basically consistent with Zhaai Shandingzi whose characteristics of the sexual reproduction are distinct; and compared with Pingyi Tiancha, they did not have the complex phenomena during the process of the embryogenesis. General speaking, the sexual reproduction was the main reproductive mode of the leaf-wrinkled and dwarf plants which had the low level ability of apomixis.

Key words: Malus, Pingyi Tiancha, Zhaai Shandingzi, The leaf-wrinkled and dwarf plant, Embryogenesis