假俭草铝耐性和敏感种源在酸铝土上的生长差异及生理响应

在前期实验中利用水培法对48份假俭草种源进行耐铝鉴定基础上,本实验采用土培法研究了5份耐铝假俭草种源和5份铝敏感假俭草种源在酸铝土壤上的生长以及活性氧系统的差异。结果表明,在酸铝土壤上生长28d后,2类型种源所测的6个生长指标中,除了株高外均存在显著差异,耐性种源的根长、发根数、根系体积、分支数、匍匐茎长度平均减少了16.4%,23.9%,37.3%,26.7%和18.3%,敏感种源这5个生长指标平均减少了34.4%,53.8%,51.5%,52.6%和47.9%。生长的动态变化的分析结果表明,耐性种源在酸铝土壤上可以保持较高的生长速率。酸铝胁迫引起假俭草体内超氧阴离子产生速率和丙二醛含量增加,敏感种源增加幅度较大,诱导SOD、POD活性的增加,耐性种源增加幅度较大,说明假俭草可以通过提高体内的SOD、POD酶活性来缓解铝毒害,耐铝假俭草的代谢酶活性对铝胁迫更为迅速。

The growth and physiology response of Al-tolerant and Al-sensitive centipedegrass accessions on aluminum soil

Based on the evaluation of aluminum tolerance among 48 centipedegrass accessions, the difference of growth index and reactive oxygen system of Al-tolerant and Al-sensitive centipedegrass accessions after growing in aluminum soil for 28 days was assessed. Significant differences were found among five growth indexes, but not plant height. There was a considerable negative effect of aluminum stress on root length, number of roots, root volume, numbers of tillers and stolon length of 10 centipedegrass, with an average reduction of 16.4%, 23.9%, 37.3%, 26.7%, 18.3% respectively for these growth indexes in Al-tolerant accessions and 34.4%, 53.8%, 51.5 %, 52.6%, 47.9% in Al-sensitive accessions. The dynamic changes of growth in the 10 accessions indicated that tolerant accessions could maintain a higher growth rate compared with sensitive accessions when growing in the aluminum soil. The rate of superoxide anion radical formation and the MDA content of centipedegrass increased under aluminum stress, and the increased range of sensitive accessions was higher than that of the tolerant accessions. The aluminum stress resulted in an increase of SOD and POD activity, which was greater in the tolerant accessions than that in the sensitive accessions, suggesting that centipedegrass could alleviate the effects of aluminum toxicity by increasing SOD and POD activity. The production of SOD and POD among the Al-tolerant accessions was quicker than that of the sensitive accessions when suffering aluminum stress.