BEHAVIOR OF VESICULAR-ARBUSCULAR MYCORRHIZAL FUNGI IN ANDO-SOIL AND THEIR ROLES ON CROP GROWTH

1. 研究了VA菌根真菌在大学农田-富含腐殖质的安多土壤中的行为与农艺措施差异的关系。在饲料作物田间每100g空气干燥土壤中检出的VAM真菌孢子总数约为400 ~ 600个，孢子数为bbb53 μ m，其中Gromus spa占99%以上，而Gigaspora margarita和Scutellospora gregaria仅检出少量孢子。虽然发现了Gromus spp.的几种差异，但这些差异尚未被确定。2. 研究了连续施用农家肥和磷肥对玉米和冬小麦VAM侵染及生长的影响。农家肥和磷肥对两种作物的VAM侵染均有抑制作用，其中玉米吐丝期和小麦繁殖期侵染率最高，达45- 50%。在最大侵染期，芽部VAM侵染率与P %呈显著正相关。VAM侵染率与茎干重呈显著负相关关系。3. 聚乙烯地膜覆盖通过提高表层土壤温度（约5 ~ 10℃）促进大豆生长，加速VAM侵染，诱导早期磷吸收，增加根瘤形成。土壤炭处理也通过在根际为VAM真菌创造良好的微环境而增强了VAM的侵染，使植物在低肥力和较高肥力条件下均能提高生长。4. 从饲料作物田间分离到的一株尚未鉴定的grmus spp（孢子表面颜色为黄色），在含有63.3ppm Bray II-P的安多土壤消毒后的盆栽中，对大豆和鹰嘴豆的生长产生了极大的刺激作用，使籽粒产量和茎部磷含量比对照提高了300%以上，而对小麦和玉米的生长没有显著的促进作用，说明VAM真菌可能存在一定的寄主特异性。在相同条件下，大豆和鹰嘴豆对玛格丽塔赤霉病反应不明显。5. 土壤连续施用除草剂（3年），只有在连续种植非菌根作物（卷心菜）时，VAM真菌孢子才会减少。少

1. Behavior of VA mycorrhizal fungi in University farm field - humus rich Ando-soil - was studied in relation to the differences in agronomic practices. Total number of VAM fungus spores (>53 um) collected from forage crop field was around 400-600 per 100g air dry soil, in which Gromus spp. occupied more than 99%, whereas only a few numbers of Gigaspora margarita and Scutellospora gregaria were detected. Though several differences in species of Gromus spp. were recognized, those were not yet identified. 2. The effects of continuous application of farmyard manure and phosphatic fertilizer on VAM infection and the growth of maize and winter wheat were examined. Farmyard manure and phosphatic fertilizer decreased additively the VAM infection on both crops, in which maximum infection reached up to 45-50 % at silking stage of maize and at reproductive stage of wheat. Positive coorelations between VAM infection % and P % in shoots were observed at the stage of maximum infection. However, the … More interrelationships between VAM infection % and dry weight of shoots whenever shown in significance were always negative. 3. Mulching with polyethylene film promoted the soybean growth through higher temperature in surface soil (increase in about 5-10 c), inducing in P absorption at earlier stage due to accerelation of VAM infection as well as the increase in nodule formation. Charcoal application to the soil also enhanced VAM infection through preparing favorable micro-environment for VAM fungi in rhizosphere, resulting in increase in plant growth under not only low, but relatively higher fertility condition. 4. The one of Gromus spp., not yet identified (surface colour of spore was yellow), isolated from forage crop field stimulated extremely soybean and chickpea growth in pots with sterilized Ando-soil having 63.3ppm of Bray II-P, resulting in more than 300% in grain yield and 500% in P in shoots as compared with control, whereas there was no significant promotion in wheat and maize growth, indicating that there may be some host specificities among VAM fungi. Few resposes of soybean and chickpea to Gigaspora margarita were observed under the same condition. 5. Continuous application of herbicides (3 years) to the soil decreased VAM fungus spores only when non-mycrrhizal crops (cabbage) were continuously cultivated. Less