施磷和接种AM真菌对玉米耐盐性的影响

Effect of phosphorus and arbuscular mycorrhizal fungus on response of maize plant to saline environment

在盆栽条件下研究了不同施磷水平 (2 5 ,5 0 ,10 0 ,15 0mg/kg) ,不同盐水平 (NaCl0 ,1.2 g/kg)和不同接种AM真菌处理 (接种和不接种 )对玉米生长的影响。结果表明 ,施磷量为 5 0mg/kg时基本满足玉米生长的需要。1.2 g/kgNaCl胁迫显著抑制了玉米的生长 ;施磷明显促进玉米在盐胁迫条件下的生长。施磷水平和接种菌根真菌的交互作用对玉米耐盐性具有显著影响 :盐胁迫条件下 ,接种AM真菌在低磷 (2 5mg/kg)条件下对玉米生长和吸收磷有显著促进作用 ,在高磷 (10 0和 15 0mg/kg)条件下 ,对玉米生长的影响则不显著 ;施磷量为 5 0mg/kg时 ,接种AM真菌的玉米植株含磷量与不接种处理的相当 ,但接种处理的玉米植株干重却显著高于不接种处理的。可以认为 ,AM真菌提高植物耐盐性的机理不是唯一的 ,当植物对磷的需求得到满足时 ,AM真菌还可以通过其他途径使植物的耐盐性得到一定程度的提高 。

Maize (\%Zea mays \%L.) were grown for 65 days in pots containing sterilised soil with four phosphorus levels (25, 50, 100 and 150 mg/kg) and two salinity levels (0 and 1.2 g/kg NaCl) supply. Maize plants were inoculated with or non\|AM fungus 〔\%Glomus mossese \%(Nicol. & Gerd.) Gerdmann & Trappe〕. The results showed that salinity inhibited plants growth at all four phosphorus levels and phosphorus supply promoted plants growth. There were significant interactive effects between AM fungus and phosphorus supply on the growth and phosphorus state of maize plants under both saline and non\|saline conditions. AM fungus increased the dry weight and phosphorus content at lower phosphorus supply (25 mg/kg) significantly, but had no effects on both dry weight and phosphorus content at higher phosphorus supply (100 and 150 mg/kg) of maize plants. Under salinity stress and 50 mg/kg phosphorus supply condition, there was no significant difference of phosphorus concentration between mycorrhiza and non\|mycorrhiza plants, but the dry weight of mycorrhiza plants was significantly higher than that of non\|mycorrhiza plants. It is concluded that the improvement of phosphorus state of plant is the main and dominant mechanism by which AM fungus enhances plant salinity tolerance in phosphorus deficient soil. However, when phosphorus supply is sufficient, AM fungus is still able to enhance the salinity tolerance of plant by other mechanisms.