狗牙根品种在华北地区自然低温下的耐寒适应性研究-园林植物与观赏园艺专业论文.docxVIP

period than the others. The green period range of local bermudagrass materials was 178～ 189 days; C1 had reached the longest green period of 189 days. The dates turning green and withering away in 2008 were later than 2007, A5 (189 days) and C3 (181 days) had more shorter green period, C1 (189 days) had no change in green period, while A3 (182 days) had more longer green period. The new materials C12 and C14 had the shorter green period. Integrate the color, density, quality and uniformity of the turf, the appearance quality indexes of two yeas all showed that the American varieties have better quality than the local ones during the experimental periods, and the quality score order of American varieties in 2007 is A5A2A3A4. American varieties A2, A3 and A5 had higher turf quality in summer, while A4 had slightly poorer turf quality due to the vertical growth property. The quality scores order of local varieties is C1C4C2C3，Only C1 had higher turf quality among local materials. The quality scores order in 2008 is A5A3C12C1C14C3，the new introduced varieties C12,C14 has a high quality score and should have a deeper research in the condition of natural low temperature . and turf texture was the greatest factor which restrict the application of local materials. We conclude that C1 and A5 contained the highest chlorophyll than other materials through two years’ study. The chlorophyll contents order of four materials which studied both years was C1A5C3A3, C12 、 C14 which studied in 2008 contain lower chlorophyll ,while higher damage rate。 The measurement of cold resistance in autumn showed: The relative conductivity of all the bermudagrass materials had a downtrend, and the sequence of the four materials average in both years was A5C1C3A3; C12 and C14 which studied in 2008 had the worst cold-resistance. The change of plasma membrane was one of physiological indexes that could effectively measure cold-resistant ability of Bermudagrass. Electrolyte effusion rate and curve’s