Characterization of a Rhizobium Strain AA18 Isolated from Acacia auriculiformis

耳莢相思樹根瘤茵Rhizobium茵株AA18之特性分析

王維洋(Wei-Young Wang) ； 王涼綢(Liang-Chou Wang)

《林業試驗所研究報告季刊》 9卷1期 (1994/03) Pp. 11-20

https://doi.org/10.7075/BTFRI.199403.0011

摘要

自臺東太麻里耳莢相思樹林地採集之根瘤中，分離得到一株快生型根瘤菌Rhizobium菌株AA18，並針對其生理特性包括生長速率、產酸或產鹼反應、黏質物產生、剛果紅吸收與在39℃、2%氯化鈉及對不同酸鹼值之耐受性，以及不同有機酸鹽類對其生長影響等進行分析。結果顯示菌株AA18可在含有檸檬酸鹽、乙醛酸鹽、乳酸鹽與丙酮酸鹽之基礎培養基上生長，此與其它根瘤菌不同而與Rhizobium meliloti之特徵相似。此菌株可與臺灣相思樹及耳莢相思樹共生而形成根瘤，利用種子細菌被覆法進行接種時，感染率分別為84%與77%。但直幹相思樹利用種子細菌被覆法進行接種，其感染率僅達8%，而黑栲則完全不感染。故菌株AA18之寄主範圍較狹窄且臺灣相思樹及耳莢相思樹對菌株AA18具有較高之感受性。接種並感染之相思樹幼苗，其高生長較對照組增加二至三倍，而苗木乾重則較對照組增加二至五倍。接種方式經比較，結果以種子細菌被覆法效果最佳。

關鍵字

相思樹 ； 根瘤菌 ； 生理特性 ； 接種 ； 寄主專一性

並列摘要

A fast-growing Rhizobium strain designated AA18 was isolated from Acacia auriculiformis root nodule. The physiological characteristics such as growth rate, acid production, mucoid production, sodium chloride tolerance, pH sensitivity, Congo red absorption and growth in media containing various organic acids were evaluated. The strain is unique in its ability to grow in basal salts medium containing citrate, glyoyxlate, lactate and pyruvate as compared to other rhizobia isolates. Based on these results, the strain AA18 is similar to R. meliloti. The strain formed root nodules with A. confusa and A. auriculiformis and the infection rates were 84% and 77%, respectively, when inoculated by the seed-coating method. However, the same method only produced 8% infected seedlings in A. mangium and none in A. mearnsii. These results indicated that AA18 has a narrow host range and A. confusa and A. auriculiformis are more susceptible to AA18. Seedlings inoculated with AA18 increased 2-3 folds and 3-5 folds in height and dry weinght, respectively, as compared to the non-inoculated controls. Among the four inoculation methods used in this study, seed coating with bacteria slurry was the most effective method.

並列關鍵字

Acacia ； Rhizobium strain ； physiological characteristics ； inoculation ； host specificity