高温胁迫下白三叶种子萌发特性及耐热性研究

Studies on Seed Germination Characteristics and Heat Tolerance of Trifolium repens L. under High Temperature Stress

通过不同温度处理,对7个白三叶品种的种子萌发特性和耐热性进行了研究。结果表明,40℃胁迫下种子不发芽;在20～35℃范围内,白三叶种子发芽率随温度升高而降低,变温(20℃16 h,35℃8 h)处理可改善高温对种子萌发的抑制程度;相比变温和低温处理,高温(25～35℃)处理缩短了种子萌发所需的时间。高温处理可促进胚根的发育,变温处理对胚根也有这种作用,但抑制胚芽的生长。不同品种对高温的耐受能力不同,通过耐热性综合评价,可将白三叶品种划分为3个耐热等级,其中胡依阿属于耐热性强的品种,雷托、克劳和鄂牧1号耐热性中等,海法、路易斯安那和G 18耐热性较弱。

The germination characteristics and heat tolerance of Trifolium repens under different high tempera-ture stress were studied.The results showed that seeds could not germinate at the temperature of 40 ℃.From 20 ℃ to 35 ℃,the germination rate reduced with the increasing of temperature,but it could be improved by the treatment of changing temperature（20 ℃16 h,35 ℃8 h） continually.Compared to the treatment of changing temperature and low temperature,the high temperature（25 ℃ to 35 ℃） shortened the germination process.Ra-dicels grew better at the temperature of high temperature（25 ℃ to 35 ℃） and changing temperature than that of at 20 ℃,but changing temperature restrained the growth of seedlings.Different varieties had different toler-ance to high temperature.By comprehensive appraisal of heat tolerance,all varieties of Trifolium repens were classified to three heat tolerance levels.The heat tolerance of Huia was strong,and the varieties Retor,Crau and E mu No.1 were intermediate,and haifa,Louisiana and G 18 were weak.