Screening Indole acetic-acid over-producing rhizobacteria for improving growth of lentil under axenic conditions

Rhizobium inoculation has successfully been used for improving growth and yield of legume crops in different parts of the world. This study evaluated the in vitro auxin production of forty PGPR strains and the effect of eight selected superior strains on bacterization of lentil seeds under axenic conditions. Seed inoculation with superior IAA-producing bacterial strains and recommended Rhizobium leguminosarum biovar. viciae significantly enhanced seedling germination and vigour, root and shoot length, root and shoot fresh and dry weight The most pronounced increase in root length was observed with isolate 37P+R (7.7 cm) as compared to control (3.4cm). This increase may be attributed to the presence of IAA which increases root surface area and length, and thereby provides the plant greater access to nutrients. Similar result was found in case of shoot length where isolate 37P alone and in combination with Rhizobium boosted shoot length, maximum being 8.0 cm in comparison to control (2.1 cm). Three isolates 12B, 35P and 37P were found to be most promising in IAA, Gibberellins, Siderophore, HCN production and phosphate solubilization