The Role of Endomycorrhizas in Mineral Nutrient Uptake by Crop Plants.

结果表明，在不施磷的条件下，将囊泡丛枝菌根真菌、摩西球囊霉（Glomus mosseae）和丛枝菌根真菌（G.在全磷含量高而速效磷含量低的辐照过的阿索土（砂壤土）中接种etunicatus。在未灭菌的土壤中加入磷酸盐也能促进大豆的生长，菌根和非菌根大豆地上部对<^（32）P>标记的土壤磷酸盐积累的磷具有相似的比放射性。菌根大豆对水培液中Fe &lt;^（32）P&gt;<O_4>或Al &lt;^（32）P&gt;<O_4>的吸收与非菌根大豆的吸收基本一致。接种G。mosseae不能解释菌根大豆地上部磷积累增加的原因。结果表明，在具有较强固磷能力的黑土上，内生菌根菌在土壤中的固磷作用主要是由于菌根菌丝网络的延伸超出了根毛区，从而促进了作物对磷的吸收，添加竹炭粉可有效地提高土壤中G. mosseae和G.结果表明，在肥力良好的阿索土和Sadohara土（砂壤土）中，土壤中的Eutunicatus的数量最多。但泡囊丛枝菌根对土壤中移动的性较差的锌、铜等养分的吸收没有促进作用，接种效果较好的内生菌根真菌，可增加作物对土壤中磷的吸收，从而节省磷肥的施用量。

The dry matter production, seed yield and phosphorus accumulation of soybean greatly increased irrespective of phosphate fertilization when a mixture of spores of vesicular-arbuscular mycorrhizal fungi, Glomus mosseae and G. etunicatus was inoculated in irradiated Aso soil (andosol) which had high total phosphate content but low available phosphate content. The growth stimulation also occurred in the unsterilized soil with added phosphate.Mycorrhizal and nonmycorrhizal soybean shoot had a similar specific radioactivity of phosphorus accumulated from <^(32)P> -labelled soil phosphate. Absorption of <^(32)P> by mycorrhizal soybean from Fe <^(32)P> <O_4> or Al <^(32)P> <O_4> added in water-culture solution was almost identical with that by nonmycorrhizal soybean. Changes in Al-phosphate content of Aso soil inoculated with G. mosseae did not always explain the increased accumulation of phosphorus in mycorrhizal soybean shoot. These results show that endomycorrhizas largely contribute the phosphate absorption of crop plants in andosol having large phosphate fixing capacity due to the extension of a network of mycorrhizal hyphae beyond the root-hair zone.The addition of powdered bamboo charcoal efficiently increased the rate and density of infection with G. mosseae and G. etunicatus in well-fertilized Aso and Sadohara soil (andosol). However, vesicular-arbuscular mycorrhizas did not stimulate the absorption of less mobile nutrients, zinc and copper from the soils.Inoculation with better endomycorrhizal fungi will increase phosphate absorption by crop plants from soil and may in turn save phosphate fertilizer to be applied.