云南2种野生苜蓿资源对酸铝胁迫的响应分析

Analysis on Acid-aluminum Stress Response of Two Wild Alfalfa Resources in Yunnan

以云南2种野生苜蓿资源为材料,采用水培法研究酸铝胁迫对幼苗生长的影响。通过分析酸、铝单一及复合处理下幼苗根长、株高、生物量、根系活力、叶绿素和丙二醛含量、过氧化物酶和超氧化物岐化酶活性变化,比较2种苜蓿对酸、铝的耐性。结果显示:随着酸度的增加,天蓝苜蓿和紫花苜蓿幼苗的生长均受抑制,pH 7.0和pH 3.0处理对比分析,天蓝苜蓿在根长、株高、生物量、根系活力增幅比紫花苜蓿的增幅小;铝胁迫后,2种苜蓿在根长、株高、生物量、根系活力指标上均具有显著差异,且随着铝浓度的增大,受抑制越严重;酸、铝共同胁迫对2种苜蓿幼苗生长的影响大于单一胁迫对它的影响,pH 4.5,Al3+浓度300 mg/L时,2种苜蓿生长受抑最严重。酸、铝单一胁迫及复合处理均显著影响2种苜蓿,但天蓝苜蓿对酸、铝及酸铝的耐性优于紫花苜蓿。

Two wild alfalfa resources(Medicago lupulina, Medicago sativa) in Yunnan were used to study the effects of acid-aluminum stress on alfalfa seedling growth under water culture. The tolerance of the two alfalfa to acid and aluminum was compared by analyzing the changes of peroxidase and superoxide dismutase activities, root length, plant height, biomass, root vigor, chlorophyll content, malondialdehyde content under single and compound treatment of acid and aluminum. The seedling growth of the two alfalfas was inhibited significantly under acidity treatment. Comparation with pH 7.0 and pH 3.0, the root length, plant height, biomass and root activity of M. lupulina increased less than that of M. sativa. There were significant differences in the indexes for root length, plant height, biomass, root vigor between the two alfalfa resources under aluminum treatment. Seedling growth was seriously reduced with the increase of aluminum concentration. The influences of acidity and aluminum compound treatment on the seedling growth of the two alfalfa were greater than those of either stress in isolation. The growth of the two alfalfa was most severely inhibited under the pH 4.5, Al3+ 300 mg/L treatment. Under the conditions of acid, aluminum or acid-aluminum stress treatments, the tolerance of M. lupulina to acid, aluminum and acid-aluminum was better than that of M. sativa from the point of view of the indexes of growth or decline of seedling growth, physiological indicators, inhibition rate.