培養液に添加されたフェノール物質分解菌が水耕キュウリの栄養生長に及ぼす効果

The herbicide, 2, 4-dichlorobenzoic acid (DCLBA), was administered through the nutrient solution to six cucumber seedlings grown hydroponically. DCLBA, which is also a synthetic auxin, stunts cucumber plants at a low concentration but kills at a higher one. Roots of six comparable seedlings, treated with DCLBA, were exposed to two strains of microorganisms, TS-22 and TS-29, and Rhizoplane AC1, which were isolated from soils and cucumber roots. The control cucumber seedlings, unexposed to DCLBA and the different strains of microorganisms grew vigorously, whereas those exposed to DCLBA were stunted. The stature of seedlings, exposed simultaneously to DCLBA and TS-22, TS-29, and Rhizoplane AC1, was nearly that of the control, but their fresh and dry weights were approximately 2/3 and 1/2, respectively, of the untreated control seedlings. These results demonstrate that there are microorganisms in the soil and on cucumber roots which, if added to the nutrient solution, can catabolize DCLBA.