Abstract: In order to analyze the effects of different types of inducers on the cold resistance of Kentucky bkuegrass (Poa pratensis),the experiment was conducted to study the effects of different concentrations of chitosan (0,20,50,100,200,300,400 and 500 μmol·L^-1),betaine(0,20,40,60,80,100,120 and 140 μmol·L^-1) and melatonin(0,25,50,100,200,300,400 and 500 μmol·L^-1) on the physiological characteristics of Poa pratensis ‘Baron’ under low temperature stress(day 4℃/night 0℃,light 14 hours a day,darkness 10 hours,light intensity 3500-4000 Lux,relative humidity 60%). The results showed that spraying the appropriate concentration of inducers could effectively alleviate the damage of P. pratensis seedlings under low temperature stress. The relative conductivity and malondialdehyde content of P. pratensis seedlings treated with three kinds of inducers were lower than that of control seedlings under low temperature stress,and showed a trend of first decreasing and then increasing. The contents of chlorophyll,soluble sugar,soluble protein and free proline increased first and then decreased,and the activity of antioxidant enzymes increased significantly. The cold resistance membership function of each index was calculated and sorted. It was found that 300 μmol·L^-1 of melatonin had the best treatment effect.

Key words: Poa pratensis, Inducer, Low temperature stress, Physiological characteristics

摘要： 为了分析不同类型诱导剂对草地早熟禾(Poa pratensis)低温抗性的影响，本试验以草地早熟禾‘巴润’为材料，研究低温胁迫(白天4℃/黑夜0℃，每天光照14 h，黑暗10 h，光强3500~4000 Lux，相对湿度60%)下喷施不同浓度的壳聚糖(0，20，50，100，200，300，400和500 μmol·L^-1)、甜菜碱(0，20，40，60，80，100，120和140 μmol·L^-1)和褪黑素(0，25，50，100，200，300，400和500 μmol·L^-1)对草地早熟禾生理特性的影响。结果表明：喷施适宜浓度的诱导剂均能有效缓解草地早熟禾幼苗受低温胁迫危害，三种诱导剂处理的草地早熟禾幼苗相对电导率和丙二醛含量均低于低温对照幼苗，并呈先降后升的趋势；叶绿素、可溶性糖、可溶性蛋白和游离脯氨酸含量呈先升后降趋势，抗氧化酶活性显著提高；通过计算各指标抗寒隶属函数值并排序发现，三种诱导剂中以300 μmol·L^-1浓度的褪黑素的处理效果最佳。

关键词: 草地早熟禾, 诱导剂, 低温胁迫, 生理特性