水分胁迫对引进牧草渗透调节物质及叶绿素荧光参数的影响

Effects of Water-stress on Osmoregulation Substances and Chlorophyll Fluorescent Parameter for Forage Grass

通过盆栽控水试验,分析了8种美国引进禾本科牧草在不同水分胁迫下叶片的叶绿素、脯氨酸、可溶性糖含量和叶绿素荧光参数等的变化.结果表明,叶片叶绿素相对含量总体呈随水分胁迫程度加剧而降低的趋势,并在严重胁迫(HWS)下达到最低;在轻微水分胁迫(SWS)下各牧草脯氨酸含量增加缓慢,随水分胁迫的进一步加剧而急骤升高;可溶性糖含量随水分胁迫的加剧而持续增加;叶绿素荧光参数Fv/Fm、Fv/Fo、ΦPSⅡ均随水分胁迫加剧先升高后降低,在轻度水分胁迫下达到最大,但各草种间变异情况不同.运用隶属函数法所得牧草综合抗旱性强弱顺序为:Ⅳ>Ⅰ、Ⅷ>Ⅱ>Ⅴ>Ⅲ>Ⅵ>Ⅶ,运用萎蔫系数直接评价的抗旱性结果为:Ⅳ>Ⅷ>Ⅰ>Ⅱ>Ⅲ>Ⅴ>Ⅵ>Ⅶ,即猫尾草(Ⅰ)、无芒雀麦(Ⅳ)和新麦草(Ⅷ)抗旱性较强,而细茎披碱草(Ⅵ)、高冰草(Ⅶ)较差.

In order to evaluation the effects of water stress, chlorophyll, praline, soluble sugar and fluorescence of chlorophyll of 8 forage grass were analyzed,with the experiment on pot culture with water stress. The results indicated that the variations of chlorophyll content decreases with increased water stress, the content of chlorophyll was least at HWS disposal method; The content of proline increased slowly with slight water stress,the proline content increased sharply with heavy water stress; soluble sugar contents sustainable increase with aggravation water stress; the content of Fv/Fm,Fv/Fo,ФpsⅡ were increased first with water stress and then decreased,the content of Fv/Fm,Fv/Fo,ФpsⅡ were highest at SWS disposal method;The index of 8 kinds of forage were evaluated by the Subjectionqunction method,the results indicated that the sequence of drought of 8 kinds of forage was Ⅳ〉Ⅰ、Ⅷ〉Ⅱ〉Ⅴ〉Ⅲ〉Ⅵ〉Ⅶ ; with the wilting coefficient drew the sequence of drought of 8 kinds of forage was Ⅳ〉Ⅶ、Ⅰ〉Ⅱ〉Ⅲ〉Ⅴ〉Ⅵ〉Ⅶ. The synthetical evaluation results showed that Ⅰ , Ⅳ and Ⅶ forage have stronger drought resistance,while Ⅵ and Ⅶ forage have weaker drought resistance.