The Study On Cultivation And Drought Resistance Of Hypnum Plumaeforme

By split-plot and the broadcast sowing method of stem-cutting, the influence of light and substrate on the growth of Hypnum plumaeforme was studied. Furthermore, the drought stress response in the substrate of peat under different shading was explored. The purpose of the study was to provide theoretical evidence for the large scale cultivation, garden development and utilization of bryophytes. The main conclusions were obtained as follows:1. Study on cultivation: The effect of light and substrate had a highly significant difference on the coverage of H. plumaeforme(P<0.01), while the interaction of them was not significant(P>0.05). As for the light effect, there was significant difference between the full daylight and shading, and 60% shading was the most beneficial in which the coverage of H. plumaeforme among each substrate was up to 93% or more(except in sand ). The best combination for the growth of H. plumaeforme was 60% shading and peat. The branch length and number of H. plumaeforme varied under different light and substrate. The branch length was the shortest under full daylight, and increased with the enhancement of shading, while the branch number among different substrates from high to low was sand > saw powder > peat > pine bark > garden soil > clay.2. Study on physiological characteristics: Under drought stress, the leaves of H. plumaeforme were back-curling and the leaf color changed from green to yellow green or brown. The relative water content of tissue and chlorophyll content all decreased, especially in the first 10d when the relative water content reduced the fastest. The relative conductivity reached to maximum after drought stress for 10d and it was high up to 48.3% under the full daylight and down to 31.7% under the 60% shading. With the prolongation of drought stress the MDA content increased, which reached to peak under different light conditions after drought stress for 20d. Under the drought stress, the content of soluble sugar and soluble protein increased firstly and then decreased, while the content of soluble sugar of 60% shading was remarkably lower than that of the 40% shading. SOD activity and POD activity changed similarly, both of which increased firstly and then decreased. The relative water content and chlorophyll content increased within 24h after re-watering, while relative water content increased the fastest. Meanwhile, the relative conductivity, the content of soluble sugar, the content of soluble protein, SOD activity and POD activity all went up again within a narrow range and then decreased, but SOD and POD still kept higher activity. The MDA content decreased gradually, while 120h after re-watering the MDA content of 60% shading decreased to 93.1% of that at the initial experiment stage. From comprehensive comparison,we concluded that the H. plumaeforme under the 60% shading had the strongest resistance to drought stress.By comparison and analysis, we concluded that 60% shading and peat substrate were the most suitable condition for the growth of H. plumaeforme by the gametophyte breeding way. Moreover, H. plumaeforme in 60% shading had a stronger resistance and adaptability to drought stress than that in other light conditions.