Study On Root And Shoot Characters Of Six Different Kentucky Bluegrass Cultivars

Kentucky bluegrass (Poa pratensis L.) with strong resistance, suitable scope, holding long green period, bright colors, developed root systems, the great quality, and other fine features. So many species have been the indispensable excellent cool-season turfgrass in the northern city of China, and have widely used in the city greening, landscape design and sports filed planting cool-season turfgrass. Therefore, Kentucky bluegrass has a very broad prospect of application in our urban greening and landscape industry.The study discuss the shoot character and root distribution characteristics of six Kentucky bluegrass cultivars, that is "Baron", "Mallard", "Brilliant", " Starburst", "Midnight" and "Bewitched". Hoping to obtain the differences of the six Kentucky bluegrass cultivars in the shoot features and root biomass distribution characteristics. In addition, explore a method which will more easily for operation, timely and labor-efficient, no destructive to root by comparing the traditional root measurement and tracking root method. To provide a reference for the research of Turf Establishment and Management, and have a certain theoretical and practical significance for the promotion of the lawn industry.The results showed that with the, the day-growth changes of the leaf dry weight, leaf surface area and leaf number were days increase consistent. There is no much difference between the six Kentucky bluegrass cultivars. Tillers'daily increase changes have a substantial reduction at the beginning, and then increase slowly; there has been a small decrease after 56 days. The day-growth changes of the six Kentucky bluegrass cultivars'traced root total length present upward trend; the day- increase rate of traced root total length, traced root total number and traced root total surface area were almost exactly the same;6 Kentucky bluegrass cultivars'leaf dry weight accumulation, leaf number, leaf surface area and tiller number raised with days change. However, the changes of all varieties were not very clear in the indexes; the main roots of Kentucky bluegrass cultivars mainly distribute in the range of zero to ten centimeter of the sand layer, the rate was more than 70% of root biomass; root total length and total root surface area were 65% of the total amount; the root to shoot ratio of each species all remained at about 0.40. The root to shoot ratio descending order is that, "Baron">"Starburst">"Bewitched">"Mallard"="Brilliant">"Midnight"; The measured total root length of traced and actual was consistent, and then the measured total root surface area of traced and actual is not entirely consistent; the traced total root length and actual total root length was a significant positive correlation , coefficient was 0.885, between traced total root surface area and actual total root surface area also present a significant positive correlation, the correlated coefficients were 0.817,this result shows that traced method can be used as a kind of determination method of root indicators. And the method has the advantages of simple operation, easily observed, labor-efficient. Speculation in the six varieties of Kentucky bluegrass, "Bewitched" has stronger drought resistance, next is "Mallard" and "Brilliant", followed by "Starburst" is slightly inferior to"Brilliant", "Baron" and " Midnight"were poorer than others.