The Quality Characteristics Assessment Of4Cool-grasses In Yangzhou Region

In this study, some new and representative species of foreign turf grass were selected to conduct a comparative experiment on their ecological adaptability and turfing quality under the circumstance of temperate continental semi-drought climate in Yangzhou District. With some representative index system and scientific standard of the evaluation of turf quality, an analysis was made on their density, coverage, color, texture, uniformity, green period, grassing speed, wintering and summering rate. Meanwhile, a pot experiment was made to simulate the effects of high temperature stress (38/28℃for day and night) on the5physiological and biochemical indexes of cold season turf grass, i.e. their plasma membrane permeability, proline and MDA contents, and POD and SOD activities so as to study their heat resistance. The results were:(1) Under the same level of management, the4cold-season turf grasses had the similar seeding date, full seeding date and grassing date with an order of Perennial ryegrasse>Tall Fescue>Bentgrass> Kentucky bluegrass. This had noting to do with species, which showed that the one seeding early also grassed fast.Among the4species planted in Yangzhou, their comprehensive quality varies. Each turf grass had its own adaptability that differs from any other else in this district, therefore it should be carefully selected according to its function and the local climate. Varieties of Kentucky bluegrass, especially the Blue Sapphire, had the best comprehensive quality with good texture, coverage, adaptability and grassing value, made it top one of these cold season turf grass and the best choice for local planting. Perennial ryegrasse grew fast but lack heat resistance that hardly could any of them summer safely, made it not suit the local use but a pioneering grass. Varieties of Tall Festuca had strong heat resistance and adaptability, but coarse texture and tough leaves which was not suitable for the landscaping but sports ground and public green grass. Among those, Plantation performed best. Bentgrass had soft texture and long period of green, which was particularly good for local introduction.(3) Simulate the high temperature stress on the4grasses by manual control of temperature. With the increasing time of the high temperature stress, the leaf relative conductivity and free proline and MDA contents of the grasses presented an increasing trend, being significantly higher (P<0.05) than the controlon the8th days after the stress, whereas the POD and SOD activities showed a trend of increasing first and decreased then. A comprehensive analysis showed that varieties of Festuca arundinacea have the strongest resistance of heat, folowing varieties of Poa and Perennial ryegrasse and the resistance of bentgrass is weaker compared with those former. Among those, RebleⅣ and Blue Sapphire had better performance than the other varieties.(4) Varieties of Festuca species performed better than any other species in all biological indexes and had the best heat resistance; Varieties of Poa was not as good as Festuca, but also had a fairly good heat resistance. The biological indexes of Perennial ryegrasse and bentgrass were almost the same, and performed similarly in heat resistance.