| The field turf quality characteristics of 28 Poa pratensis (Kentucky bluegrass) varieties introduced from overseas were evaluated, and band pattern and double wave scanning characteristics of EST and POD Isozyme were analyzed for 26 varieties among them. Assessments on drought resistance of 11 Kentucky bluegrass varieties at seedling stage were conducted under pots experiment conditions. Moderate soil moisture and effect of silicon on morphological and physiological response were also studied with the variety of Baron. The main results were:Single factor measurement results of the turf quality of 28 Kentucky bluegrass should very significant quality characteristic differences among varieties, and they could easily be classified into different types. Varieties with the highest density were Limousine and Elysee (1.45/cm~2). Monoply had the highest coverage (87.1%). Elysee and Limousine had the narrowest leaves (2.57mm and 2.74mm). Growth characteristics performed in three types, semi-perpendicular (including Julia), semi-creeping (including Sydsport), and middle type. There were five color groups. Only one variety had slight winter yellowing and withering (Entopper). Others showed medium or severe symptoms. Fylking showed the longest green period (336 d), followed by Barlin, Bar 5649, Conni, Entopper, and Monpoly (333 d). 28 verities could be divided into three types, namely, dense and fine type, medium type, and sparse and coarse type based on the cluster analysis results combined density, coverage, growth characters, texture, color, and green period.Band pattern and Double wave scanning characteristics of EST and POD Isozyme were analyzed for 26 varieties of Kentucky bluegrass, Cluster analysis were conducted with the Euclidean distances acted as the heretic parameters. The results are showed that, In terms of EST Isozyme, the bands number is ranged from 12 to 36,No.3 occurred most (36) and No.12 Fortuna occurred lest (12) .In terms of POD Isozyme bands numbers ranged from 5-23, the No.14 Geronino occurred most (23), No.3 Bar5649 and No.18 Merit occurred lest (5). Using two Isozyme band pattern, 26 varieties can be classified into 2 first rank groups, 3 rank second groups and 4 rank third groups with the linkage distance. The combination of the two kinds pattern of POD and EST can provide a reference to the Kentucky bluegrass usage and variety identification.Drought resistance in 11 KBG varieties in pot experiments in the greenhouse was assessed. The rate of germination, survival, and vertical growth of each variety increased as field water capacity (FWC) decreased from 70% (FWC 70) to 50% (FWC 50), and men decreased from 50% to 30% (FWC 30). Tillering rate and shoot-to-root ratio decreased as the FWC decreased from FWC 70 to FWC 30. Proline content and electrolyte leakage (EL) in leaves of KBG at FWC 50 was lower than those at FWC 30 and FWC 70. Under FWC 30, representing drought stress, rate of germination, survival rate of seedlings, vertical growth rate, and shoot-to-root ratio were significantly different among the 11 varieties. Based on the rate of germination, 'Barlin' and 'Baron' performed best. According to the survival rate of seedlings, 'Baron' preformed best. For vertical growth rate, 'Barlin' and 'Compact' were superior to others. 'Barlin' was the best variety in terms of lower shoot-to-root ratio. 'Barlin' and 'Baron' had higher proline accumulation and greater cell membrane stability (lower EL) in leaves. Using rate of germination, survival rate, vertical growth rate, shoot-to-root ratio, proline content, and EL as analysis factors, cluster analysis indicated that 'Baron' and 'Barlin' had better resistance to drought than other varieties, and suggested that they are suitable for sowing in arid and semi-arid regions because of their strong drought resistance at the seedling stage.Effects of moisture on the development of Kentucky bluegrass were conducted based on five moisture conditions. The results showed that evapotranspiration (ET), tillers per plant, leaf length, leaf width, and leaf area decreased along with the soil moisture. Treats with the highest germination were FWC 50 and FWC 40. Higher soil moisture can increase the vertical growth of Baron, while lower soil moisture restricts it. Coverage of five moisture conditions classified into 2 groups, and it much higher in FWC 60, FWC 50, and FWC 40 conditions than in FWC 70 and FWC 30 conditions. Further study show that ET was significantly or most significantly restricted by vertical growth, leaf length, leaf area and tillers per plant. The cluster result shows that FWC 50 and FWC 40 were the moderate soil moisture for Kentucky bluegrass.Effects of silicon on the drought resistance of Kentucky bluegrass were conducted based on four moisture treatments and five silicon concentrations. The results showed that evapotranspiration increased with the added soil moisture. Using silicon increased the vertical growth, tillerring rate, root growth, and numbers of green leaves. Silicon also has great effects on RWC, membrane permeability and proline content in Kentucky bluegrass. But silicon can also delay the emergency time of Kentucky bluegrass.
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