Studies On The Spores Propagation Of Ornamental Ferns And Drought Resistance Of Several Ornamental Ferns In Nanjing City

Ornamental ferns with their singular foliage are one part of ornamental foliage plants. Because of their varied ecosystem type and shade-tolerance , they are vary important in the ornamental plant. On the basis of investigating the resource of ferns in Nanjing city, 16 adaptable ornamental ferns were selected to investigate and explain their ornamental character, habitat, phenology and use in garden. Spores germinating rates of 2 ferns, spores propagation of 3 ferns, drought resistance of 4 ground cover ferns were studied. The results were summarized as follows:Ⅰ. There are 51 species of ferns belonging to 31 genera in 20 families in Nanjing city. Among which there are 16 ornamental fern species, because of their varied habitat and highly ornamental function, have potential for use in garden.Ⅱ. Spores geminating rates of Dryopteris erythrosora were between 47.96 to 66.80 percent after 10 days of cultivation. It has lowest geminating rate on MS culture medium without any hormone, and has highest geminating rate on 1/4 MS +c 1mg/l KT+1.2mg/l GA +3 % sugar. Pteris multifida spores have higher geminating rates, which were between 80.18 to 94.99 percent. 1/4 MS +2mg/l KT +0.2 mg/l NAA+0.6mg/l GA is the best medium for spores germination.Ⅲ. In different medium time Pteris multifida, Cyrtomium fortunei and Dryopteris erythrosora spores need to germinate and to form gametophyte and sporophyte are different, and the developing condition of gametophyte and sporophyte are different, too. Substrate which was a mixture of the garden soil and peat-soil with the same volume is the best one, and pure sand is the worst.Ⅳ. The intensity of light have some influence on spores germination, gametophyte and sporophyte development. Fully sunshine do some good to spores germination, gametophyte form and development. But in summer, fully sunshine always lead to high temperature, in which gametophyte and young sporephyte are easy to die. There are little difference between the other two intensity of light, but 50 percent sheltered sunshine is relatively better.Ⅴ. The ability of drought resistance of the four fern species were: Pteris multifida >Dryopteris erythrosora ≈D. atrata >Cyrtomium fortunei. In addition, It can be seen that membrance permeabity, Chlorophyll content, SOD activities, MDA content and Pro content can easily reflect the ability of drought resistance of ferns, and can be used as photosynthetic targets to study drought resistance of ferns. The ability of leaves to hold water and the ratio of Chlorophyll a to b can partially reflect the ability of drought resistance, can only be refered.