Short Communication

Selection and evaluation of Rhizobial strains of Vigna radiata L. beneficial to biological nitrogen fixation

Neeraj¹*, Gaurav S.S.¹, Sachin² and Chandra M³

¹Department of Biotechnology, C.C.S. University, Meerut-250110 (U.P) India.

²Division-FLOF, Central Institute of Medicinal and Aromatic Plants, Lucknow- 226015 (U.P), India.

³Scientific and Applied Research Center, Meerut. U.P. INDIA

*Corresponding author. E-mail: neerajtandan@gmail.com. Tel: +91-121-2762021, (Ext-2119).

Accepted 15 August, 2008

This study aimed to select suitable strains that can be used as inoculants to enhance legume production and simultaneously reduce the use of inorganic fertilizers.  Evaluations of the selected strains of Vigna radiata on the basis of polysaccharide (exopolysaccharides and lipopolysaccharides) produced reinforced evidence that Rhizobial strains and its mutant nodulate promote growth differently under stressed environments. Strains performance evaluation demonstrated that the R0132 (1106):Tn5 inoculant of Sinorhizobium fredii (Formerly, Rhizobium fredii) is a prime candidate as a commercial inoculant. It benefited growth of V. radiata and it was more easily cultured on solid and liquid media than any of the other strains tested including R0132 (1112):Tn5, R0132 (0097):Tn5 and R0132 (1106):Tn5. Mutant R0132 (1106):Tn5 exhibited superior growth promoting ability under extreme environmental condition; therefore it has potential to be used in India.

Key words: Rhizobial mutant, biological N₂ fixation.