盐胁迫下丛枝菌根真菌对玉米水分和养分状况的影响

Effect of AM fungi on water and nutrition status of corn plants under salt stress.

在NaCl胁迫下无论接种AM真菌与否玉米植株生物产量均减少 ,但不接种处理的减少幅度比接种处理的高 10个百分点左右 .盐胁迫下接种AM真菌的玉米根系和地上部的干重、叶片水势均高于不接种处理、叶片脯氨酸含量低于不接种处理 .在盐胁迫下真菌菌丝对玉米植株磷营养的贡献由 45 .3 %降为 42 .6% ,AM真菌对植株生长的效应反而由 3 0 .9%提高到 63 .5 % ,说明AM真菌提高玉米耐盐性的机理与改善植物的水分状况和P营养状况都有关系 .试验同时还发现无论有无盐胁迫 ,接种AM真菌的玉米植株根系累积P量与地上部累积P量之比值均高于不接种的 ,即AM真菌侵染改变了P在植物体内的分配规律 ,这一特征对提高植物耐盐性是有利的 .

Under NaCl stress,the dry matter production of corn plants inoculated with or without arbuscular mycorrhizal (AM) fungus ( Glomus mosseae) was decreased,but the decrement for non mycorrhizal plants was 10% higher than that for mycorrhizal ones.Under salt stress condition,the dry weights of root system and aboveground part of mycorrhizal corn and its leaf water potential were higher than those of non mycorrhizal corn, while the proline content of mycorrhizal corn was less than that of non mycorrhizal corn.The contribution of hypha to P uptake of plants decreased from 45\^3% to 42\^6%,while the effect of AM fungi on plant growth increased from 30\^9% to 63\^5% under salt stress condition.The above mentioned results indicated that the mechanism that AM fungi enhance the salt resistance of corn is related with the improvements of water and P nutrition conditions.Meanwhile,it was found whether under salt stress or not,the ratio of P accumulation of root system to aboveground part of mycorrhizal corn was higher than that of non mycorrhizal corn,indicating that the infection of AM fungi changed the P distribution pattern in plant bodies,which is beneficial to increase the salt resistance of plants.