两个高羊茅品种苗期抗旱性的比较

Comparison of Drought Tolerance between the Seedlings of Two Festuca arundinacea Cultivars

黔草1号(Qiancao No.1,QC1)和黔草2号(Qiancao No.2,QC2)是从贵州本地野生高羊茅(Festuca arundi-nace)中选育出的品种。用PEG6000(0 Mpa、-1.5 MPa、-2.5 MPa)处理两个高羊茅品种幼苗4d,以测定叶片中脯氨酸(proline,Pro)、丙二醛(malondialdehyde,MDA)含量和超氧化物歧化酶(superoxide dismutase,SOD)活性。随着胁迫时间的延长,两个高羊茅的Pro、MDA含量均增加,SOD酶活性先增加再下降;同时,-2.5 MPa处理条件下各参数测定值最大,0 MPa处理最小且差异不明显。表明在干旱胁迫下两个高羊茅都是通过积累较多的脯氨酸、维持较高的SOD酶活性,以清除细胞中的氧自由基,减缓细胞中MDA的生成,保护细胞的结构和功能,叶片细胞对-2.5 MPa胁迫的响应程度高于-1.5 MPa胁迫条件。与QC2相比,QC1叶片中Pro含量和SOD酶活性较高、丙二醛含量较低。说明QC1的抗旱能力强于QC2。

To compare the drought tolerance between two tall fescues（Festuca arundinace） cultivars,Qiancao No.1（QC1） and Qiancao No.2（QC2）,the seedlings of QC1 and QC2 were subjected to osmotic stress with polyethylene glycol 6000（PEG 6000） at 0 MPa,-1.5 MPa and-2.5 MPa in the present work.Accumulation of proline,malondialdehyde（MDA） and activity of superoxide dismutase（SOD） in leaves were measured at different treatments.Proline and MDA in QC1 and QC2 increased with the treatment time prolonged.The SOD activity of QC1 and QC2 enhanced in the first two days,followed by two-day＇s decrease.The content of proline or MDA and SOD activity in both cultivars got their ceiling at-2.5 MPa.The best way for survival of two tall fescues from drought stress laid to increase the proline content and SOD activity,so as to maintain the structure and function of cells.Stress injury to cells got most severe at-2.5 MPa since.Compared with QC2,the proline content and SOD activity were higher in QC1,conversely MDA accumulation was much lower,suggesting that QC1 is more tolerant to drought tolerance.