ARS | Publication request: EFFECT OF DROUGHT ON THE GROWTH AND SURVIVAL OF RHIZOBIUM MELILOTI STRAINS FROM PAKISTAN AND NEPAL

Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 29, 1996
Publication Date: N/A

Interpretive Summary: Alfalfa is widely used for forage production in Pakistan and is grown in areas with prolonged drought. Rhizobia are important soil bacteria that form unique associations with alfalfa that enable alfalfa plants to biologically fix nitrogen or produce its own fertilizer. It would be beneficial to have rhizobia that are capable of surviving under drought conditions so that alfalfa plants can fix a maximum amount of nitrogen. I this study we evaluated the influence of drought on the growth and survival of 10 rhizobial strains from Pakistan and Nepal. Results showed that two rhizobia strains (UL 136 and UL 222) survived the best under drought and should be considered for commercial inoculant production in Pakistan and possibly other arid and semiarid environments.

Technical Abstract: Growth and survival of 10 competitive strains of Rhizobium meliloti Dang. from Pakistan and Nepal were evaluated for their survival under drought in vials filled with sterile soil maintained at -0.03, -1.0 and -1.5 MPa. Rhizobia in the soil-filled vials were enumerated at 0, 4, 8, 14, 21 and 28 days after inoculation. Highest number of rhizobia g-1 of soil were observed at -0.03 MPa followed by soil maintained at -1.0 and -1.5 MPa. Strains UL 136 and UL 222 survived the best under drought and should be considered for commercial inoculant production in Pakistan.