【作者】 钟华友；

【导师】 曹卫星；

【作者基本信息】 南京农业大学 ， 作物栽培学与耕作学， 2003， 硕士

【摘要】 高温炎热是气候过渡区冷季型草坪草夏季生长主要的胁迫因子。冷季型草坪草耐寒不耐热，最适的地上部生长温度是15-24℃，根系为10-18℃。在气候冷凉地区能周年常绿，在我国长江流域，其绿色期也相对较长，但在夏季高温季节却普遍存在难以越夏的问题。本试验以冷季型草坪草高羊茅(Festuca arundinecea Schreb. CV. Huntdog 5)为材料，通过NO(Ommol/L)、N3(3mmol/L)、N6(6mmol/L)和N9(9mmol/L)四个N素处理，研究了高温胁迫条件下N素对高羊茅草坪草耐热性的影响，结果表明： 1．在适温条件下，高羊茅草坪草生物量、叶绿素含量以及其它各项生理指标均随N素水平的增加而提高，表现为N素效应。 2．N6和N9处理高羊茅草坪草生物量在30/25℃达到高峰后，35/30℃下降较大，叶绿素含量、类胡萝卜素含量以及根活力、SOD、POD酶活性等其它一系列指标均在30/25℃达到高峰后，急剧下降。而N0和N3处理各指标基本上在35/30℃达到最高后下降。表明高N(N6、N9)水平的耐胁迫温度较低，而低N(N3)以及不施N的耐胁迫温度较高。 3．在极端高温(40/35℃)的胁迫条件下，N9处理在第3天后枯死，N6处理在第6天后死亡，而N0和N3处理第九天后仍然存活，但N3处理的生物量和叶绿素含量均高于N0处理，而其它各项抗性生理指标均低于N0处理，表明适当的N素处理虽然降低高羊茅草坪草的抗性，但可以提高高温胁迫下草坪的总体质量， 4．不同N素处理根系各指标的变化幅度均大于茎叶，根系对高温的敏感度大于茎叶。当温度高于35℃时，虽然高羊茅草坪草的茎叶脯氨酸、丙二醛含量高于根系，但根系的脯氨酸、丙二醛含量上升幅度大于茎叶，植株仍表现出较好的长势。根系的生物量、根系活力、SOD活性和POD活性明显下降，下降幅度大于茎叶。 5．夏季高温季节适当施用氮肥是提高高羊茅草坪质量的措施之一，本研究中，N0处理在热胁迫下具有最好的抗逆性，但叶色差，草坪质量较差。N9处理在热胁迫下表现最差，不值得提倡。而N3处理既具有较好的抗逆性，又有较好的草坪质量，值得加以应用。更多还原

【Abstract】 High temperature is the major factor limiting growth of cool-season turf grass in transitional zones. The optimum temperature for cool-season turf grass range from 15 to 24 C for shoot growth and 10 to 18 C for root growth. It can be evergreen year round in cool climate zone. In Yangtze River transitional zones it has long green period. But in summer, it can hardly survive from heat stress. The trial studies the effects of nitrogen on tall fescue, a cool-season turf grass, under heat stress by four nutrient solutions concentration such as NO (0mmolN/L), N3 (3mmolN/L), N6 (6mmolN/L) and N9 (9mmolN/L) .The main results were as follows:1. The biomass , chlorophyll and other physiological index of tall fescue under optimum temperature were increase as nitrogen level increase, which manifest nitrogen effective.2. The biomass of tall fescue turf grass with N6(6mmol N /L) , N9(9mmol N /L) treatment reached its climax in 30/25 C, and then decreased rapidly. So did the chlorophyll and carotenoid content, POD and SOD activity , root activity. But index of N0(0mmol N/ L), N3(3mmol N/ L) treatment reached its climax in 35/30 C, and then decreased. It suggested that stress temperature of high nitrogen level is lower than that of low nitrogen level.3. When the temperature was higher than 35/30 C, proline and MDA content of shoot were more than those of root. But the increasing rate of proline and MDA content in root were more hgher than those of shoot, and the decreasing rate of root biomass , root activity, SOD and POD activity were larger than those of shoot. It suggested that heat sensitivity of root was larger than that of shoot.4. Under the utmost heat stress(40/35 C), tall fescue plants of N9 treatment died 3 days after treatment(DAT), and N6 treatment died 6 DAT, NO and N3 treatment still lived 9 DAT. But the biomass and chlorophyll content of N3 treatment were more than NO treatment, while other index were less than NO treatment. The result shows that suitable nitrogen level could improve the overall quality of tall fescue turf despite decreased its heat tolerance to some extent.5. Employing nitrogen fertilizer suitably in summer was one of the management to improve tall fescue turf quality. In this study, the effect of N3 treatment was the best, and N6 treatment followed, NO and N9 treatment was the worst.更多还原