干旱胁迫对不同禾本科牧草叶绿素荧光特性的影响

本试验以无芒雀麦、垂穗披碱草、老芒麦、细茎冰草为试验材料,研究了干旱胁迫处理下不同禾本科牧草的叶绿素荧光参数、叶片电导率和脯氨酸（Pro）含量变化的对比。结果表明：随着干旱胁迫程度的加剧,4种禾草初始荧光（Fo）和非光化学淬灭系数（qN）呈现逐渐上升趋势,而最大荧光（Fm）,潜在光化学效率（Fv/Fo）,最大光化学效率（Fv/Fm）和光化学淬灭系数（qP）呈现逐渐下降趋势。上述参数的变化幅度因材料抗旱性强弱而异,这种差异可作为简便评价禾草抗旱性强弱的鉴定指标,因此,运用隶属函数对不同禾草抗旱性进行评价分析,得出抗旱性强弱次序为：垂穗披碱草〉无芒雀麦〉细茎冰草〉老芒麦。

EFFECTS OF DROUGHT DRESS ON CHLOROPHYLL FLUORESCENCE PARAMETERS IN LEAVES OF FORAGE GRASSES

The chlorophyll fluorescence parameters （Fo）, leaf conductance and proline content changes of four forage grasses, such as, Bromus inermis, Elymus nutans, Elymus sibiricus, Agropyron trachycaulum were meas- ured and analyzed under different drought stress treatment in the study. The results showed that： With the degree of drought stress, the minimal fluorescence （Fo） and non--photochemical quenching coefficient （qN） of four gras- ses trend to rise gradually, and the maximal fluorescence （Fro）, maximal photochemical efficiency of PS Ⅱ （Fv/ Fro） and photochemical quenching coefficient （qP） trended the gradual decline. Drought resistance changed range of the parameters for material strength. This difference could serve as a simple appraisal index for evaluation of the drought resistance in grass species. The order of the drought resistance for four grasses obtained by the analy- sis of membership function was Elymus nutans 〉 Bromus inermis 〉 Agropyron trachycaulum 〉 Elymus sibiri-cus.