三種繡球屬內生菌根菌對矮性四季豆之生長與磷肥吸收的影響及菌根所利用的土壤磷源

Effects of Glomus Species Three Endomycorrhizal Fungi on the Growth and Phosphate Uptake of Bush Snap Bean (Phaseolus vulgaris var. humilis Alef) and the Source of Phosphate in Soil Absorbed by the Mycorrhizal Roots

矮性四季豆（Phaseolus vulgaris var. humilis Alef）分別接種三種內生菌根菌孢子（Glomus mosseae, Glomus fasciculatus，Glomus vesiculifer），種子播種七天後即有感染現象。施氮、磷、鉀肥的土壤情況下，菌根與非菌根株無論在豆莢產量、地上、地下部的鮮、乾重均無顯著差異。而施氮、鉀肥的土壤情況下，地下部鮮、乾重則顯示差異，即接種的植株測值較高，但未達顯著差異標準，而地上部鮮、乾重及地下部根瘤鮮重，菌根與非菌根植株間則達顯著差異標準。不施肥的情況下，土壤本身的氮、磷含量不高，菌根與非菌根植株，地上、地下部鮮重差異達顯著標準，而乾重之差異，卻未達顯著差異標準。施氮、鉀肥及不施肥的情況下，菌根植株的豆莢產量均高於非菌根植株。菌根幫助矮性四季豆吸收大量的磷肥，使植株生長得良好，且與非菌根植株呈顯著差異。此外，菌根與非菌根植株吸收及利用的土壤中磷31與磷32之比活性相近，初步判斷二者所利用的磷肥來源相同，並可認為菌根較非菌根有較大的磷吸收功能，而利於植株的生長。

The effetcs of three endotrophic mycorrhizal fungi (Glomus mosseae, Glomus fasciculatus, Glomus vesiculifer) on growth, phosphate uptake of bush beans (Phaseolus vulgaris var. humilis, Alef) were studied. When the inoculation was done during seed sowing, it was found that only after 7 days of inoculation, the bean roots were already infected by the fungi. When the bush beans were treated with N, P, K fertilizers, there were no significantly different for the number of bean pods produced, neither for the fresh and dry weight of both shoot and root of mycorrhizal and nonmycorrhizal plants. When only N and K were applied, although fresh and dry weight of root showed some differences, yet no significantly level was reached. But fresh and dry weight of shoot and fresh weight of nodule were significantly different. When no fertilizer was applied, it was found that the soil used for this experiment contained low level of N and P. The bean pods and fresh weight of both shoot and root were significantly more in the infected plants but dry weight of both shoot and root were not significantly different. The mycorrhizal plants produced significantly more dry matter and removed more phosphorus from soil than non-mycorrhizal plants. But they did not show increased ³²p activity per unit of P mass. The results suggested that both mycorrhizal and non-mycorrhizal plants took up P from the same source of the slowly-available P from the soil. The major function of mycorrhizal fungi was to obtain more efficient exploitation of the labile pool of soil phosphate.