九个苜蓿品种叶绿素荧光参数与叶水势日变化研究

在田间旱作条件下,对9个苜蓿品种的叶绿素荧光参数、叶片水势及其日变化进行了观测。结果表明:不同苜蓿品种的初始荧光(Fo)、可变荧光(Fv)、PSⅡ最大光能转化效率(Fv/Fm)、光合性能指数(PI)波动趋势呈单峰曲线,均在中午出现峰值,方差分析得出Fm、Fv、Fv/Fm、Fv/Fo以及PSⅡ活性中心数(RC/ABS)均表现出极显著差异(P<0.01),基于叶绿素荧光参数参试品种聚为两大类,第一类包括准格尔苜蓿、草原2号、敖汉苜蓿、中苜1号和龙牧801,叶绿素荧光特性较优,第二类包括肇东苜蓿、甘农3号、公农1号和龙牧803,叶绿素荧光特性较差;9个苜蓿品种水势日变化较大,其中准格尔苜蓿和敖汉苜蓿叶片水势较高且较为稳定,而公农1号和肇东苜蓿叶水势较低。准格尔苜蓿、草原2号、敖汉苜蓿、中苜1号和龙牧801对环境耐受性较好,肇东苜蓿、甘农3号、公农1号和龙牧803对环境耐受性较差。

Studies on Chlorophyll Fluorescence Characters and Leaf Water Potential in Nine Alfalfa Varieties

The chlorophyll fluorescence characters,leaf water potential and diurnal fluctuations in nine varieties of alfalfa under dry farming were observed.The results showed that the diurnal fluctuations of the chlorophyll fluorescence parameters of nine varieties of alfalfa were nearly in the same trends,peak values appeared at noon.The differences in all the characters such as Fm,Fv,Fv/Fo,Fv/Fm and RC/ABS were extremely significant(P<0.01) and the nine varieties of alfalfa can be classified into two groups based on these chlorophyll fluorescence characters,one group including Zhungeer,Caoyuan No.2,Zhongmu No.1,Aohan and Longmu No.801,which were better in chlorophyll fluorescence characters,the other group including Zhaodong,Gannong No.3,Gongnong No.1 and Longmu No.803,which were poorer in chlorophyll fluorescence characters.And there were great diurnal fluctuations in leaf water potential among nine varieties of alfalfa,the leaf water potential of Zhungeer and Aohan was higher and more stable than the other varieties,especially Gongnong No.1 and Zhaodong.In conclusion,the varieties including Zhungeer,Caoyuan No.2,Zhongmu No.1,Aohan and Longmu No.801 were better in resistibility than the other varieties including Zhaodong,Gannong No.3,Gongnong No.1 and Longmu No.803.