五种丛枝菌根真菌对白三叶耐铜污染的影响

Effects of Five Arbuscular Mycorrhizal Fungi on the Tolerance of White Clover(Trifolium repens) to Copper Contamination

采用盆栽试验研究了副冠球囊霉、摩西球囊霉、根内球囊霉、聚丛球囊霉和幼套球囊霉五种丛枝菌根(AM)真菌接种处理的白三叶对Cu污染的生理反应。结果表明:(1)Cu污染土壤中接种根内球囊霉显著提高了白三叶地上部和根部鲜重、株高和主根长,菌根依赖性依次为:根内球囊霉>摩西球囊霉>幼套球囊霉>聚丛球囊霉>副冠球囊霉。(2)AM真菌(副冠球囊霉除外)接种株地上部POD、CAT活性及根内球囊霉接种株SOD活性均显著高于对照,根内球囊霉、幼套球囊霉和副冠球囊霉处理显著降低了地上部MDA含量;AM真菌接种株叶绿素含量及根内球囊霉、摩西球囊霉接种株地上部脯氨酸含量亦显著高于对照。(3)根内球囊霉和幼套球囊霉处理显著提高了地上部及根部Cu含量,摩西球囊霉接种株根部Cu含量亦显著增加,而副冠球囊霉处理降低了根部Cu含量,五种处理中以根内球囊霉处理的地上部/根系Cu转运系数最大。(4)AM真菌(副冠球囊霉除外)接种株地上部与根部Zn含量、根内球囊霉和幼套球囊霉接种株地上部与根部P含量均显著高于对照,同时聚丛球囊霉和副冠球囊霉处理显著提高了地上部P含量;AM真菌显著提高了根部K含量,对地上部K含量无显著性影响;根内球囊霉处理地上部Mg含量增加,AM真菌(幼套球囊霉除外)接种株根部Mg含量显著高于对照;此外,AM真菌处理显著增加了地上部Ca(聚丛球囊霉处理除外)和根部Ca(副冠球囊霉处理除外)含量。可见,根内球囊霉接种处理最有利于白三叶对Cu污染土壤的修复,幼套球囊霉处理的修复效果次之,副冠球囊霉处理的修复效果相对较弱。

A pot experiment was conducted to study the responses of white clover （Trifolium repens） inoculated with five arbuscular mYcorrhizal（AM） fungi Glomus coronatum, G. mosseae, G. intraradices, G. aggregatum and G. etunicatum to copper contamination. In copper polluted soil, G. intraradices inoc- ulation increased shoot and root fresh weights, plant height and main root length, the order of mycorrhizal dependency was G. intraradices G. rnosseaeG, etunicatum G. aggregaturn~ G. coronatum. White clover inoculated with AM fungi（G, coronatum excluded） maintained higher peroxidase and catalase activi- ties, G. intraradices inoculation also increased superoxide dismutase activity, and G. intraradices, G. etunicatum and G. coronaturn infection decreased malondialdehyde contents in shoots relative to corresponding non-AM control, there were more chlorophyll contents in AM plants, as well as higher proline contents in G. intraradices, G. mosseae and G. coronatum inoculated plants. G. intraradices and G. etunicatum inoculation significantly increased copper （Cu） contents in shoots and roots, while G. mosseae infection also increased Cu content in root, however, G. coronatum inoculation decreased Cu content in root, and ratio of Cu in shoot colonized by G. intraradices was the highest among the five treatments. Inoculation with AM fungi（G, coronatum excluded） increased zinc contents in shoots and roots, G. intraradices and G. etunicatum infection increased phosphorus（P） contents in shoots and roots, meanwhile, P contents were higher in G. aggregatum and G. coronatum inoculated shoots than in non-AM shoots. AM symbiosis increased potassium（K） contents in root significantly, but had little influences on K contents in shoot, G. intraradices treatment increased magnesium（Mg） content in shoots, and AM infection（G, etunicaturn ex- cluded） increased Mg contents in root markedly, in addition, AM fungi inoculation increased calcium con- tents in shoots（G, aggregatum excluded） and roots（G, coronatum excluded）. In summary, G. intraradi- ces inoculation was most beneficial to remediation of Cu etunicatum inoculation, and the effect of G. coronaturn contaminated soil by white clover, followed by G. inoculation was relatively weak.