铝胁迫对多花黑麦草生长和生理的影响

选取5个多花黑麦草(Lolium multiflorum)品种为受体材料,在水培条件下分析了不同浓度的铝胁迫对5个多花黑麦草品种种子萌发、幼苗生长及生理特性的影响。结果表明:(1)铝胁迫对多花黑麦草种子萌发及幼苗生长的影响表现为"低促高抑"。与对照相比,25mg/L低浓度铝胁迫下多花黑麦草的发芽率、根长、株高、单株鲜重增加;当铝浓度增加为50 mg/L时,多花黑麦草幼苗生长受到抑制;当铝浓度500mg/L时,多花黑麦草种子萌发和幼苗生长受到显著抑制;当铝浓度1 000mg/L时,多花黑麦草幼苗生长受到严重抑制,根系停止生长,株高、单株鲜重显著下降。(2)低浓度铝胁迫下(0~50mg/L),多花黑麦草叶绿素含量、可溶性糖含量、丙二醛、过氧化物酶和超氧化物歧化酶活性变化不大;中等浓度铝胁迫下(100mg/L),多花黑麦草叶绿素含量显著降低,可溶性糖和丙二醛含量显著增加,过氧化物酶和超氧化物歧化酶活性显著增强(P0.05);高浓度铝胁迫下(500mg/L),多花黑麦草叶绿素、可溶性糖和丙二醛含量降低,过氧化物酶和超氧化物歧化酶活性降低。多花黑麦草的铝胁迫阈值为100mg/L。

Effects of aluminum stress on growth and physiological of five cultivars of Lolium multiflorum

Five cultivars of annual ryegrass were selected as receptor materials,and seed germination,seed-ling growth and physiological response of annual ryegrass to aluminum stress was measured in this study.The results showed as follows:(1 )the effect of aluminum stress on germination and seedling growth of annual ryegrass showed the 'Hormesis effect'.Compared with the control,the germination rate,root length,plant height and fresh weight of annual ryegrass increased with aluminum concentration increasing as aluminum con-centration was lower than 25 mg/L.These growth characteristics of annual ryegrass decreased and restrained with aluminum concentration increasing as aluminum concentration was higher than 50 mg/L.The growth of annual ryegrass was restrained significantly as aluminum concentration was higher than 500 mg/L.The growth of annual ryegrass was restrained seriously and the growth of root was stopped,the plant height and fresh weight decreased significantly as aluminum concentration was higher than 1000 mg/L.(2)The content of chlo-rophyll,soluble sugar,malondialdehyde (MDA),superoxide dismutase (SOD)and peroxidase (POD)of annual ryegrass kept the same level as aluminum concentration was lower than 50 mg/L.The chlorophyll content of annual ryegrass decreased,while the content of soluble sugar,MDA,SOD and POD increased significantly as a-luminum concentration was between 50 and 100 mg/L.The content of chlorophyll,soluble sugar,MDA,SOD and POD of annual ryegrass decreased significantly as aluminum concentration was lower than 500 mg/L.The aluminum stress threshold value for annual ryegrass growth is 100 mg/L.