內生菌根菌Glomus clarum盆栽接種試驗證明能促進玉米及大豆之生長。本試驗選用適當宿主（Host）百喜草（Paspulum notatum）來保存菌種並繁殖之。網室盆栽大豆接種試驗，結果顯示植株表現有益效應最適當之最初感染源量（Initial inoculum density）為每棵200個厚膜孢子。內生菌根之形成能促進植株自土中吸收磷素營養，尤其是被固定之磷源或礦物磷、鐵結合磷、鋁結合磷及鈣結合磷。玉米及大豆田間接種內生菌根菌G clarum能增進植株生長並提高單位面積產量，尤其在低磷肥土壤，玉米接種內生菌根菌並施磷肥區與單施磷肥區或不施磷肥區比較，可增產8或26％，單接種內生菌根菌區也可增產6％，大豆接種內生菌根菌區也有類似之增產效果，與不施磷肥區比較也可增產5∼8％。
Effects of Vesicular-Arbuscular Mycorrhiza on the Absorption of Phosphorus, Growth and Yield in Corn and Soybean
Y. H. Cheng and C. C. Tu
Cheng, Y. H. and C. C. Tu, 1986. Effects of Vesicular-arbuscular mycorrhiza on the absorption of Phosphorus, growth and yield in corn and soybean. Tainan District Agricultural Improvement Station Bulletin No. 20:39~52.
Effects of a vesicular-arbuscular (VA) mycorrhizal fungus, Glomus clarum, on the growth and yields of corn and soybean were investigated in the greenhouse and field experiments. The bahia grass (Paspulum notatum) was found to be a suitable host for the maintenance and multiplication of the fungus. According to the greenhouse experiment, the best initial inoculum density for soybean was 200 chlamydospores/plant. The top and root growth of corn and soybean were improved when they were infected with the fungus. The presence of VA mycorrhiza in soybean enhanced the uptake of phosphorus, especially the fixed or mineral phosphorus, such as Al-P, Fe-P, Ca-P and Carbonate-P, from soil. Field experiments also proved that VA mycorrhizal fungus could improve the phosphorus uptake and yield, especially in the soil with low level of phosphorus. The corn yield increased by 8 and 26% in the plots treated with VA mycorrhizal fungus and additional phosphate as compared with those plots treated with phosphate alone and the control. Plants infected with VA mycorrhizal fungus alone also increased their yield. Soybean inoculated with the VA mycorrhizal fungus showed similar results and 5~8% increases in yield.
Key words:Vesicular-arbuscular mycorrhiza, Glomus clarum, Initial inoculum density, corn, soybean.