AM真菌对濒危物种四合木及近缘种霸王抗旱性的影响

摘要

为探求四合木保护的菌根学途径，利用盆栽试验研究了干旱胁迫条件下丛枝菌根真菌( AMF或AM真菌)对四合木和霸王生长及抗旱性的影响。结果表明：AMF显著提高了四合木幼苗成活率，所有处理中，干旱胁迫且接种AMF处理的四合木、霸王与正常水分且不接种AMF处理相比较，株高、鲜质量相当，说明接种AM真菌有显著的促生作用。不同接种菌剂处理对四合木叶片数量无显著性影响，但不同接种剂对霸王叶片数量存在极显著性影响；接种AMF提高了四合木的超氧化物歧化酶( SOD)、过氧化氢酶( CAT)的活性，降低了过氧化物酶( POD)的活性，但霸王的SOD、CAT和POD均升高。研究表明，四合木借助提高抗氧化酶活性来适应干旱胁迫，而霸王通过减少叶片的数量，以降低蒸腾作用，提高抗氧化酶活性共同适应水分的胁迫。利用AMF菌种对濒危物种四合木保护具有重要生态学意义。%With pot experiment in a greenhouse,the paper studied the effects of Arbuscular mycorrhizal Fungi on growth and drought tolerance of Tetraena Mongolica Maxim. and Zygophyllumx anthoxylum Maxim. under drought stress. The results showed that:AMF significantly increased survival rate of Tetraena mongolica Maxim. Under differ-ent AMF treatments,Tetraena mongolica had no significant effect on root fresh weight and leaf number,while Zygo-phyllumx anthoxylum had significant effect on leaf number. AMF improved growth of Tetraena mongolica and Zygo-phyllumx anthoxylum, plant height and fresh weight of Tetraena mongolica and Zygophyllumx anthoxylum was no significant difference between drought stress,colonization and well water,no-colonization. Under AM fungal coloniza-tion,the activity of SOD and CAT in Tetraena mongolica was improved,while the activity of POD was decreased. But the activity of SOD,POD and CAT in Zygophyllumx anthoxylum was improved. The results indicated that Tetraena mongolica adapted to drought stress by increasing the AMF infection rate and coordinating antioxidant enzyme sys-tem,while Zygophyllumx anthoxylum adapted to drought stress by reducing the number of leaves and increasing the activity of antioxidant enzyme system. Therefore,by separating and screening AMF,using AMF resources to protect endangered Tetraena mongolica is of great significance.