BIOLOGY AND PHYSIOLOGY OF MALUS HUPEHENSIS FOR THE APOGAMIC PLANT RESOURCE

The Malus hupehensis is one kind of ornamental plants, commonly used as the rootstocks for apple and Chinese flowering crabapple, and also used to manufacture a special brand of tea which may reduce the animal blood sugar. Malus hupehensis is typical allotriploid (2n=3x=51), thus mainly reproducing the descendant by apogamy and can be propagated easily. The plant favors warm conditions and can endure wet. M. hupehensis has a higher level of cold and disease resistance and moderate level of drought resistance. Some types are easily infected by nematode. There are multitudinous wild types of M. hupehensis in Hubei, Sichuan, Shandong and other places in China and M. hupehensis has a high level of genetic diversity. The variety of M. hupehensis is var. pinyiensis Jiang, var. taishanensis Jiang and var. Shizongensis Jiang. Compared with other Malus spp., M. hupehensis has a moderate level of genetic variability. The apogamic ability of M. hupehensis is strongest in all apogamic Malus spp. plants, but the apogamic ability is incompletely same in different type. RAPD and isozyme analysis show M. hupehensis var. pinyiensis has higher heredity uniformity. The individual growth of var. pinyiensis is consistent and the coefficient of variability of root system is small. The plant is sensitive to soil environments and var. pinyiensis appeared to be good material for research for this reason. Many researches on root physiology, such as environment recognition, nutrition absorption, growth adjustment and so on had been carried out for the potential utilization of var. pinyiensis. The heritability of apogamic ability of var. pinyiensis was very strong, which could be used to breed apogamy rootstock of dwarf or resistance and so on by seed propagation.