Studies On Cold And Shade Tolerance Of Three Wild Whipgrass Germplasms For Low-maintance Turf

Whipgrass (Hemarthria.compressa) is perennial grass in family of Gramineae Hemarthria and is a strong stoloniferous grass with better social, economic and ecological value. Based on the study of the whipgrass material in southwest china, Sichuan agriculture university found some lines such as H036, H049 and H050 could be used as low-maintance turf. The object of the thesis was concentrated on cold and shade tolerance of the three wild lines under different treatment, and on evaluating the turf quality of different mowing heights and frequencies. The results showed that:(1) The mowing treatment experiments found that the opportune mowing heights and frequencies could reduce the growth speed, increase density and turf quality. The analysis of the turf quality counts showed that the best mowing treatment for whipgrass was mowing heights 5cm and frequencies 7 days, while the control material'Tifway' bermudagrass(Cynodon dactylon (Linn.) Pers.) was 4cm and 7 days. Under the best mowing program, the turf quality rank was:H049>H036>H050. H049 had better turf quality than other experiment material.(2) The evaluation of the cold tolerance showed that the relative conductance rate of three lines increased with the temperature decreasing, and lower than the one of 'Riviera' bermudagrass. The increase rates of three lines's soluble sugar, soluble protein and free proline contents were more than the ones of'Riviera'. This showed that the three lines had better cold-tolerance than'Riviera'. H050 had the longest green period and was the best cold-tolerance material of all. The experiment material's MDA content and the activities of SOD and POD increased while the temperature decreasing. The three lines restrained the inordinate accumulation of active oxygen by regulating the activities of SOD and POD. Based on the analysis of cold-tolerance indexes, the cold-tolerance rank was:H050>H049>H036>Riviera. H050 had the strongest quality of resistance for chilling.(3) The comparison experiment on the morphological features, physiological and biochemical characteristics, photosynthetic characteristics of three turf-type whipgrass germplasm and Paspalum vaginatum under different shades were measured for shade tolerance. The results showed that there turf-type whipgrass germaplasm showed better morphological plasticity under slight shading and medium shading; the content of total chlorophyll and chlorophyll b were increased, accordingly a/b ratio reduced significantly after shading treatment, as H049 had the lowest a/b ratio, it had better shade-tolerant; three turf-type whipgrass germplasm had higher content of soluble sugar and net photosynthetic rate than Paspalum vaginatum under shading, showed better shade-tolerant. The density of stomas on the expremantal material showed a desincreasing,and bigger desincreasing with the further more increased degree of shade;the light compensation point of expriental material shows the reducing trend, but apparent quantum yield shows a rarying increasing degree.All of those indexes indicate,whipgrass advances the ability of using ligting in low light enviromant. Comprehensive analysis showed that H049 has better shade-tolerant than the others.Based on the comprehensive analysis of turf quality, cold-tolerance and shade-tolerance, H049 has better turf quality, cold-tolerance and shade-tolerance than the other lines, so H049 would be further research.