| 摘要 | 在盆栽条件下研究了不同施磷水平 (25, 50, 100 , 150 mg/kg), 不同盐水平(N aCl 0, 1.2 g/ kg)和不同接种A M 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 50 mg/ kg 时基本满足玉米生长的需要。1 .2 g/kg NaCl 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(25 mg/ kg)条件下对玉米生长和吸收磷有显著促进作用, 在高磷(100 和 150 mg/kg)条件下 , 对玉米生长的影响则不显著;施磷量为 50 mg/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, 但改善植物磷营养状况是 AM 真菌提高植物耐盐性的主导机理。
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| Abstract | M aize (Zea mays L .)w ere grown for 65 day s 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 .)
Gerdm ann &T rappe〕 .The results showed that salinity inhibited plants grow th at all four phosphorus levels and phospho rus supply promoted plants grow th .There were significant interactive effects between AM fungus and phospho rus supply on the grow th and phospho rus state of maize plants under both saline and non-saline conditions .AM fungus increased the dry w eight and phosphorus content at lower phosphorus supply (25 mg/kg) sig nificantly , but had no effects on both dry weig ht and phosphorus content at higher phosphorus supply (100 and 150 mg/kg)of maize plants. Under salinity stress and 50 mg/kg phospho rus supply condition , there w as no sig nificant difference of phosphorus concentration between myco rrhiza and non-my corrhiza plants , but the dry weig ht of my corrhiza plants was significantly hig her than that of non-my corrhiza 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 phospho rus supply is sufficient , AM fungus is still able to enhance the salinity tolerance of plant by other mechanism s.
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