篩選叢枝菌根菌耐磷菌種可行性探討

Study on Screening of Phosphorustolerant Arbuscular Mycorrhizal Fungi

10.7099/TMSRC.199412.0195

呂斯文(Sy-Wen Leu)；張喜寧(Doris C. N. Chang)

叢枝菌根菌 ； 耐磷性 ； 菌種篩選 ； 迴避機制 ； arbuscular mycorrhizal fungi (AMF) ； phosphorus- tolerance ； screening ； avoidance mechanism

Transactions of the Mycological Society of Republic of China

9卷3&4期（1994 / 12 / 01）

195 - 211

繁體中文

採集並分析北投地區二十處田土，發現其有效磷含量介於18至295ppm之問，而每100克田土中所含叢枝菌根菌孢子數則由0粒至325粒均有分布，然其孢子發芽率僅有3%，以水洋菜法及濾膜表面發芽法進行單孢接種均未能成功純化菌種，而將田土孢子以玉米及百喜草盆栽繼代生產新生孢子後，再進行單孢接種則成功獲得31支純系，經鑑定結果至少包含三屬五種叢枝菌根菌菌種。以9支由高磷田土或高磷施肥狀況下篩選純系進行番茄盆栽試驗，結果在施用全磷強度(62ppm)Johnson營養液下，僅有對照之Glomus etunicatum一系有3% 的最高菌根感染率，顯示即使對於較適應於高磷狀況下生產的菌種，磷素的充分施用依舊是其菌根形成之最大限制因子，因此這些菌種之耐磷機制可能是以迴避機制，而非適應機制來渡過不利的高磷狀況。

20 field soil samples collected at Bei-Tou area were analyzed to contain available phosphate ranged from 18 to 295ppm, and spore numbers of arbuscular mycorrhizal fungi from 0 to 325 per 100 grams field soil. The germination percentage of field spores were so low as 3%, that no pure line inoculum could be derived by single spore culture neither with water agar method nor millipore surface germination method. Use of field soils as inocula in pot cultures of corn and Bahia grass could produce new spores, which then could be isolated into 31 lines by single spore culture. Inoculation of 9 lines, isolated from high phosphate soils or under high phosphate application, in a tomato pot trial with application of full phosphorus strengh (62ppm) Johnson solution resulted in rare or no mycorrhizal infection, with maximum of 3% in a controlled Glomus etunicatum line. These results suggested that full phosphorus supply could still be the most limiting factor for mycorrhizal synthesis even with those fungi adapted to high phosphorus conditions, therefore an avoidance mechanism, rather than an adaptation mechanism, could be used by these fungi to survive the unfavorable high phosphorus conditions.